Provided by: pigpio-tools_1.78-1.1build1_amd64 
      
    
NAME
       pigs - command line socket access to the pigpio daemon.
       /dev/pigpio - command line pipe access to the pigpio daemon.
SYNOPSIS
       sudo pigpiod
       then
       pigs {command}+
       or
       echo {command}+ >/dev/pigpio
DESCRIPTION
       The socket and pipe interfaces allow control of the Pi's GPIO by passing messages to the running pigpio
       library.
       The normal way to start the pigpio library would be as a daemon during boot.
       sudo pigpiod
   Features
       o hardware timed PWM on any of GPIO 0-31
       o hardware timed servo pulses on any of GPIO 0-31
       o reading/writing all of the GPIO in a bank as one operation
       o individually setting GPIO modes, reading and writing
       o notifications when any of GPIO 0-31 change state
       o the construction of output waveforms with microsecond timing
       o I2C, SPI, and serial link wrappers
       o creating and running scripts on the pigpio daemon
   GPIO
       ALL GPIO are identified by their Broadcom number.
   Usage
       pigs is a program and internally uses the socket interface to pigpio whereas /dev/pigpio uses the pipe
       interface.
       pigs and the pipe interface share the same commands and are invoked in a similar fashion from the command
       line.
       The pigpio library must be running, either by running a program linked with the library or starting the
       pigpio daemon (sudo pigpiod).
       pigs {command}+
       echo "{command}+" >/dev/pigpio
       pigs will show the result of the command on screen.
       The pigs process returns an exit status (which can be displayed with the command echo $?).
       PIGS_OK            0
       PIGS_CONNECT_ERR 255
       PIGS_OPTION_ERR  254
       PIGS_SCRIPT_ERR  253
       The results of /dev/pigpio commands need to be read from /dev/pigout, e.g. cat /dev/pigout (try cat
       /dev/pigout& so that all subsequent results are shown on screen).
       In both cases if an error was detected a message will have been written to /dev/pigerr (try cat
       /dev/pigerr&).  This is likely to be more informative than the message returned by pigs or the error code
       returned by the pipe interface.
       Several commands may be entered on a line.  If present PROC and PARSE must be the last command on a line.
       E.g.
       pigs w 22 1 mils 1000 w 22 0
       is equivalent to
       pigs w 22 1
       pigs mils 1000
       pigs w 22 0
       and
       echo "m 4 w w 4 0 mils 250 m 4 r r 4" >/dev/pigpio
       is equivalent to
       echo "m 4 w"    >/dev/pigpio
       echo "w 4 0"    >/dev/pigpio
       echo "mils 250" >/dev/pigpio
       echo "m 4 r"    >/dev/pigpio
       echo "r 4"      >/dev/pigpio
   Notes
       The examples from now on will show the pigs interface but the same commands will also work on the pipe
       interface.
       pigs does not show the status of successful commands unless the command itself returns data.  The status
       (0) will be returned to pigs but will be discarded.
       The status/data of each command sent to the pipe interface should be read from /dev/pigout.
       When a command takes a number as a parameter it may be entered as hex (precede by 0x), octal (precede by
       0), or decimal.
       E.g. 23 is 23 decimal, 0x100 is 256 decimal, 070 is 56 decimal.
       Some commands can return a variable number of data bytes.  By default this data is displayed as decimal.
       The pigs -a option can be used to force the display as ASCII and the pigs -x option can be used to force
       the display as hex.
       E.g. assuming the transmitted serial data is the letters ABCDEONM
       $ pigs slr 4 100
       8 65 66 67 68 69 79 78 77
       $ pigs -a slr 4 100
       8 ABCDEONM
       $ pigs -x slr 4 100
       8 41 42 43 44 45 4f 4e 4d
OVERVIEW
   BASIC
       M/MODES g m Set GPIO mode
       MG/MODEG g Get GPIO mode
       PUD g p Set GPIO pull up/down
       R/READ g Read GPIO level
       W/WRITE g L Write GPIO level
   PWM (overrides servo commands on same GPIO)
       P/PWM u v Set GPIO PWM value
       PFS u v Set GPIO PWM frequency
       PRS u v Set GPIO PWM range
       GDC u Get GPIO PWM dutycycle
       PFG u Get GPIO PWM frequency
       PRG u Get GPIO PWM range
       PRRG u Get GPIO PWM real range
   Servo (overrides PWM commands on same GPIO)
       S/SERVO u v Set GPIO servo pulsewidth
       GPW u Get GPIO servo pulsewidth
   INTERMEDIATE
       TRIG u pl L Send a trigger pulse
       WDOG u v Set GPIO watchdog
       BR1 Read bank 1 GPIO
       BR2 Read bank 2 GPIO
       BC1 bits Clear specified GPIO in bank 1
       BC2 bits Clear specified GPIO in bank 2
       BS1 bits Set specified GPIO in bank 1
       BS2 bits Set specified GPIO in bank 2
   ADVANCED
       NO Request a notification
       NC h Close notification
       NB h bits Start notification
       NP h Pause notification
       HC g cf Set hardware clock frequency
       HP g pf pdc Set hardware PWM frequency and dutycycle
       FG u stdy Set a glitch filter on a GPIO
       FN u stdy actv Set a noise filter on a GPIO
       PADS pad padma Set pad drive strength
       PADG pad Get pad drive strength
       SHELL name str Execute a shell command
   Custom
       CF1 uvs Custom function 1
       CF2 uvs Custom function 2
   Events
       EVM h bits Set events to monitor
       EVT event Trigger event
   Scripts
       PROC t Store script
       PROCR sid pars Run script
       PROCU sid pars Set script parameters
       PROCP sid Get script status and parameters
       PROCS sid Stop script
       PROCD sid Delete script
       PARSE t Validate script
   I2C
       I2CO ib id if Open I2C bus and device with flags
       I2CC h Close I2C handle
       I2CWQ h bit smb Write Quick: write bit
       I2CRS h smb Read Byte: read byte
       I2CWS h bv smb Write Byte: write byte
       I2CRB h r smb Read Byte Data: read byte from register
       I2CWB h r bv smb Write Byte Data: write byte to register
       I2CRW h r smb Read Word Data: read word from register
       I2CWW h r wv smb Write Word Data: write word to register
       I2CRK h r smb Read Block Data: read data from register
       I2CWK h r bvs smb Write Block Data: write data to register
       I2CWI h r bvs smb Write I2C Block Data
       I2CRI h r num smb Read I2C Block Data: read bytes from register
       I2CRD h num i2c Read device
       I2CWD h bvs i2c Write device
       I2CPC h r wv smb Process Call: exchange register with word
       I2CPK h r bvs smb Block Process Call: exchange data bytes with register
       I2CZ h bvs Performs multiple I2C transactions
   I2C BIT BANG
       BI2CO sda scl b Open bit bang I2C
       BI2CC sda Close bit bang I2C
       BI2CZ sda bvs I2C bit bang multiple transactions
   I2C/SPI SLAVE
       BSCX bctl bvs BSC I2C/SPI transfer
   SERIAL
       SERO dev b sef Open serial device dev at baud b with flags
       SERC h Close serial handle
       SERRB Read byte from serial handle
       SERWB h bv Write byte to serial handle
       SERR h num Read bytes from serial handle
       SERW h bvs Write bytes to serial handle
       SERDA h Check for serial data ready to read
   SERIAL BIT BANG (read only)
       SLRO u b db Open GPIO for bit bang serial data
       SLRC u Close GPIO for bit bang serial data
       SLRI u v Sets bit bang serial data logic levels
       SLR u num Read bit bang serial data from GPIO
   SPI
       SPIO c b spf SPI open channel at baud b with flags
       SPIC h SPI close handle
       SPIR h num SPI read bytes from handle
       SPIW h bvs SPI write bytes to handle
       SPIX h bvs SPI transfer bytes to handle
   SPI BIT BANG
       BSPIO cs miso mosi sclk b spf Open bit bang SPI
       BSPIC cs Close bit bang SPI
       BSPIX cs bvs SPI bit bang transfer
   FILES
       FO file mode Open a file in mode
       FC h Close file handle
       FR h num Read bytes from file handle
       FW h bvs Write bytes to file handle
       FS h num from Seek to file handle position
       FL pat num List files which match pattern
   WAVES
       WVCLR Clear all waveforms
       WVNEW Initialise a new waveform
       WVAG trips Add generic pulses to waveform
       WVAS u b db sb o bvs Add serial data to waveform
       WVCRE Create a waveform
       WVCAP percent Create a waveform of fixed size
       WVDEL wid Delete selected waveform
       WVTX wid Transmits waveform once
       WVTXM wid wmde Transmits waveform using mode
       WVTXR wid Transmits waveform repeatedly
       WVCHA bvs Transmits a chain of waveforms
       WVTAT Returns the current transmitting waveform
       WVBSY Check if waveform is being transmitted
       WVHLT Stop waveform
       WVSC ws Get waveform DMA CB stats
       WVSM ws Get waveform time stats
       WVSP ws Get waveform pulse stats
   UTILITIES
       H/HELP Display command help
       HWVER Get hardware version
       MICS v Microseconds delay
       MILS v Milliseconds delay
       PIGPV Get pigpio library version
       T/TICK Get current tick
   CONFIGURATION
       CGI Configuration get internals
       CSI v Configuration set internals
COMMANDS
       BC1 bits - Clear specified GPIO in bank 1
           This command clears (sets low) the GPIO specified by bits in bank 1.  Bank 1 consists of GPIO 0-31.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs bc1 0x400010 # clear GPIO 4 (1<<4) and 22 (1<<22)
           $ pigs bc1 32 # clear GPIO 5 (1<<5)
           -42
           ERROR: no permission to update one or more GPIO
       BC2 bits - Clear specified GPIO in bank 2
           This command clears (sets low) the GPIO specified by bits in bank 2.  Bank 2 consists of GPIO 32-53.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs bc2 0x8000 # clear GPIO 47 (activity LED on A+/B+/Pi2/Pi3)
           $ pigs bc2 1 # clear GPIO 32 (first in bank 2)
           -42
           ERROR: no permission to update one or more GPIO
       BI2CC sda - Close bit bang I2C
           This command signals that bit banging I2C on sda (and scl) is no longer required.
           Example
           $ pigs bi2cc 5
       BI2CO sda scl b - Open bit bang I2C
           This command signals that GPIO sda and scl are to be used for bit banging I2C at b baud.
           Bit banging I2C allows for certain operations which are not possible with the standard I2C driver.
           o baud rates as low as 50
           o repeated starts
           o clock stretching
           o I2C on any pair of spare GPIO
           The baud rate may be between 50 and 500000 bits per second.
           The  GPIO used for SDA and SCL must have pull-ups to 3V3 connected.  As a guide the hardware pull-ups
           on pins 3 and 5 are 1k8 in value.
       BI2CZ sda bvs - I2C bit bang multiple transactions
           This function executes a sequence of bit banged I2C operations.  The operations to be  performed  are
           specified by the contents of bvs which contains the concatenated command codes and associated data.
           The following command codes are supported:
           Name      Cmd & Data     Meaning
           End       0              No more commands
           Escape    1              Next P is two bytes
           Start     2              Start condition
           Stop      3              Stop condition
           Address   4 P            Set I2C address to P
           Flags     5 lsb msb      Set I2C flags to lsb + (msb << 8)
           Read      6 P            Read P bytes of data
           Write     7 P ...        Write P bytes of data
           The  address,  read,  and write commands take a parameter P.  Normally P is one byte (0-255).  If the
           command is preceded by the Escape command then P  is  two  bytes  (0-65535,  least  significant  byte
           first).
           The  address  and  flags  default  to  0.   The address and flags maintain their previous value until
           updated.
           No flags are currently defined.
           Example
           Set address 0x53
           start, write 0x32, (re)start, read 6 bytes, stop
           Set address 0x1E
           start, write 0x03, (re)start, read 6 bytes, stop
           Set address 0x68
           start, write 0x1B, (re)start, read 8 bytes, stop
           End
           0x04 0x53
           0x02 0x07 0x01 0x32   0x02 0x06 0x06 0x03
           0x04 0x1E
           0x02 0x07 0x01 0x03   0x02 0x06 0x06 0x03
           0x04 0x68
           0x02 0x07 0x01 0x1B   0x02 0x06 0x08 0x03
           0x00
       BR1  - Read bank 1 GPIO
           This command read GPIO 0-31 (bank 1) and returns the levels as a 32-bit hexadecimal value.
           Example
           $ pigs br1
           1001C1CF
       BR2  - Read bank 2 GPIO
           This command read GPIO 32-53 (bank 2) and returns the levels as a 32-bit hexadecimal value.
           Example
           $ pigs br2
           003F0000
       BS1 bits - Set specified GPIO in bank 1
           This command sets (sets high) the GPIO specified by bits in bank 1.  Bank 1 consists of GPIO 0-31.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs bs1 16 # set GPIO 4 (1<<4)
           $ pigs bs1 1 # set GPIO 1 (1<<0)
           -42
           ERROR: no permission to update one or more GPIO
       BS2 bits - Set specified GPIO in bank 2
           This command sets (sets high) the GPIO specified by bits in bank 2.  Bank 2 consists of GPIO 32-53.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs bs2 0x40 # set GPIO 38 (enable high current mode A+/B+/Pi2/Pi3)
           $ pigs bs2 1 # set GPIO 32 (first in bank 2)
           -42
           ERROR: no permission to update one or more GPIO
       BSCX bctl bvs - BSC I2C/SPI transfer
           This command performs a BSC I2C/SPI slave transfer as defined by bctl with data bvs.
           This function provides a low-level interface to the SPI/I2C Slave peripheral on the BCM chip.
           This peripheral allows the Pi to act as a hardware slave device on an I2C or SPI bus.
           This is not a bit bang version and as such is OS  timing  independent.  The  bus  timing  is  handled
           directly by the chip.
           The output process is simple. You simply append data to the FIFO buffer on the chip.  This works like
           a queue, you add data to the queue and the master removes it.
           I can't get SPI to work properly.  I tried with a control word of 0x303 and swapped MISO and MOSI.
           The  command sets the BSC mode and writes any data bvs to the BSC transmit FIFO.  It returns the data
           count (at least 1 for the status word), the status word, followed by any data bytes read from the BSC
           receive FIFO.
           Note that the control word sets the BSC mode.  The BSC will stay  in  that  mode  until  a  different
           control word is sent.
           For I2C use a control word of (I2C address << 16) + 0x305.
           E.g. to talk as I2C slave with address 0x13 use 0x130305.
           GPIO used for models other than those based on the BCM2711.
                 SDA   SCL   MOSI   SCLK   MISO   CE
           I2C   18    19    -      -      -      -
           SPI   -     -     18     19     20     21
           GPIO used for models based on the BCM2711 (e.g. the Pi4B).
                 SDA   SCL   MOSI   SCLK   MISO   CE
           I2C   10    11    -      -      -      -
           SPI   -     -     10     11     9      8
           When a zero control word is received the used GPIO will be reset to INPUT mode.
           The control word consists of the following bits.
           22 21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            a  a  a  a  a  a  a  -  - IT HC TF IR RE TE BK EC ES PL PH I2 SP EN
           Bits 0-13 are copied unchanged to the BSC CR register.  See pages 163-165 of the Broadcom peripherals
           document for full details.
           aaaaaaa   defines the I2C slave address (only relevant in I2C mode)
           IT        invert transmit status flags
           HC        enable host control
           TF        enable test FIFO
           IR        invert receive status flags
           RE        enable receive
           TE        enable transmit
           BK        abort operation and clear FIFOs
           EC        send control register as first I2C byte
           ES        send status register as first I2C byte
           PL        set SPI polarity high
           PH        set SPI phase high
           I2        enable I2C mode
           SP        enable SPI mode
           EN        enable BSC peripheral
           The returned status has the following format
           20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            S  S  S  S  S  R  R  R  R  R  T  T  T  T  T RB TE RF TF RE TB
           Bits  0-15  are  copied  unchanged  from  the  BSC  FR  register.   See pages 165-166 of the Broadcom
           peripherals document for full details.
           SSSSS   number of bytes successfully copied to transmit FIFO
           RRRRR   number of bytes in receieve FIFO
           TTTTT   number of bytes in transmit FIFO
           RB      receive busy
           TE      transmit FIFO empty
           RF      receive FIFO full
           TF      transmit FIFO full
           RE      receive FIFO empty
           TB      transmit busy
           This example assumes that GPIO 2/3 are connected to GPIO 18/19 (GPIO 10/11 on the BCM2711).
           Example
           $ pigs bscx 0x130305 # start BSC as I2C slave 0x13
           1 18
           $ i2cdetect -y 1
                0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
           00:          -- -- -- -- -- -- -- -- -- -- -- -- --
           10: -- -- -- 13 -- -- -- -- -- -- -- -- -- -- -- --
           20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
           30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
           40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
           50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
           60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
           70: -- -- -- -- -- -- -- --
           $ pigs i2co 1 0x13 0 # get handle for device 0x13 on bus 1
           0
           $ pigs i2cwd 0 90 87 51 9 23 # write 5 bytes
           $ pigs bscx 0x130305 # check for data
           6 18 90 87 51 9 23
           $ pigs bscx 0x130305 11 13 15 17 # check for data and send 4 bytes
           1 262338
           $ pigs i2crd 0 4 # read 4 bytes
           4 11 13 15 17
           $ pigs i2cwd 0 90 87 51 9 23 # write 5 bytes
           $ pigs bscx 0x130305 11 13 15 17 # check for data and send 4 bytes
           6 262338 90 87 51 9 23
           $ pigs i2crd 0 4
           4 11 13 15 17
           $ pigs bscx 0x130305 22 33 44 55 66
           1 327938
           $ pigs i2crd 0 5
           5 22 33 44 55 66
       BSPIC cs - Close bit bang SPI
           This command stops bit banging SPI on a set of GPIO opened with BSPIO.
           The set of GPIO is specifed by cs.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs bspic 10
           $ pigs bspic 10
           -142
           ERROR: no bit bang SPI in progress on GPIO
       BSPIO cs miso mosi sclk b spf - Open bit bang SPI
           This command starts bit banging SPI on a group of GPIO with slave select cs, MISO  miso,  MOSI  mosi,
           and clock sclk.
           Data will be transferred at baud b bits per second (which may be set in the range 50-250000).
           The flags spf may be used to modify the default behaviour of mode 0, active low chip select.
           The flags consists of the least significant 22 bits.
           21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            0  0  0  0  0  0  R  T  0  0  0  0  0  0  0  0  0  0  0  p  m  m
           mm defines the SPI mode.
           Mode POL PHA
            0    0   0
            1    0   1
            2    1   0
            3    1   1
           p is 0 if CS is active low (default) and 1 for active high.
           T  is  1  if  the least significant bit is transmitted on MOSI first, the default (0) shifts the most
           significant bit out first.
           R is 1 if the least significant bit is received on MISO first, the  default  (0)  receives  the  most
           significant bit first.
           The other bits in flags should be set to zero.
           Upon success 0 is returned.  On error a negative status code will be returned.
           If  more than one device is connected to the SPI bus (defined by SCLK, MOSI, and MISO) each must have
           its own CS.
           Example
           $ pigs bspio  9 11 12 13 50000 0
           $ pigs bspio 10 11 12 13 50000 0
           $ pigs bspio 29 19 20 21 50000 0 # GPIO 29 not avaialble on this Pi
           -41
           ERROR: no permission to update GPIO
       BSPIX cs bvs - SPI bit bang transfer
           This command writes bytes bvs to the bit bang SPI device associated with slave select cs.  It returns
           the same number of bytes read from the device.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           Example
           $ pigs bspio 5 13 19 12 10000 0 # MCP4251 DAC
           $ pigs bspio 6 13 19 12 20000 3 # MCP3008 ADC
           $ pigs bspix 5 0 16             # set DAC to 16
           2 255 255
           $ pigs bspix 5 12 0             # read back DAC
           2 254 16
           $ pigs bspix 6 1 128 0          # read ADC input 0
           3 0 3 184                       # 952
           $ pigs bspix 5 0 240            # set DAC to 240
           2 255 255
           $ pigs bspix 5 12 0             # read back DAC
           2 254 240
           $ pigs bspix 6 1 128 0          # read ADC input 0
           3 0 0 63                        # 63
           $ pigs bspix 5 0 128            # set DAC to 128
           2 255 255
           $ pigs bspix 5 12 0             # read back DAC
           2 254 128
           $ pigs bspix 6 1 128 0          # read ADC input 0
           3 0 1 255                       # 511
           $ pigs bspic 5                  # close SPI CS 5
           $ pigs bspic 6                  # close SPI CS 6
           $ pigs bspic 5                  # try to close SPI CS 5 again
           -142
           ERROR: no bit bang SPI in progress on GPIO
       CF1 uvs - Custom function 1
           This  command calls a user customised function.  The meaning of any paramaters and the returned value
           is defined by the customiser.
       CF2 uvs - Custom function 2
           This command calls a user customised function.  The meaning of any paramaters and the returned  value
           is defined by the customiser.
       CGI  - Configuration get internals
           This command returns the value of the internal library configuration settings.
       CSI v - Configuration set internals
           This command sets the value of the internal library configuration settings to v.
       EVM h bits - Set events to monitor
           This command starts event reporting on handle h (returned by a prior call to NO).
           Upon success nothing is returned.  On error a negative status code will be returned.
           The notification gets reports for each event specified by bits.
           Example
           $ pigs evm 0 -1 # Shorthand for events 0-31.
           $ pigs evm 0 0xf0 # Get notifications for events 4-7.
           $ pigs evm 1 0xf
           -25
           ERROR: unknown handle
       EVT event - Trigger event
           This command triggers event event.
           One event, number 31, is predefined.  This event is auto generated on BSC slave activity.
           Example
           $ pigs evt 12
           $ pigs evt 5
           $ pigs evt 32
           -143
           ERROR: bad event id
       FC h - Close file handle
           This command closes a file handle h previously opened with FO.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs fc 0 # First close okay.
           $ pigs fc 0 # Second fails.
           -25
           ERROR: unknown handle
       FG u stdy - Set a glitch filter on a GPIO
           Level  changes  on  the  GPIO  u  are not reported unless the level has been stable for at least stdy
           microseconds.  The level is then reported.  Level changes of less than stdy microseconds are ignored.
           The filter only affects callbacks (including pipe notifications).
           The R/READ, BR1, and BR2 commands are not affected.
           Note, each (stable) edge will be timestamped stdy microseconds after it was first detected.
           Example
           $ pigs fg 4 250
           $ pigs fg 4 1000000
           -125
           ERROR: bad filter parameter
       FL pat num - List files which match pattern
           This command returns a list of the files matching pat. Up to num bytes may be returned.
           Upon success the count of returned bytes followed by the matching files  is  returned.   On  error  a
           negative status code will be returned.
           A newline (0x0a) character separates each file name.
           Only files which have a matching entry in /opt/pigpio/access may be listed.
           Suppose /opt/pigpio/access contains
           /sys/bus/w1/devices/28*/w1_slave r
           Example
           $ pigs -a fl "/sys/bus/w1/devices/28*/w1_slave" 5000
           90 /sys/bus/w1/devices/28-000005d34cd2/w1_slave
           /sys/bus/w1/devices/28-001414abbeff/w1_slave
           $ pigs -a fl "/sys/bus/*" 5000
           ERROR: no permission to access file
           -137
       FN u stdy actv - Set a noise filter on a GPIO
           Level  changes on the GPIO u are ignored until a level which has been stable for stdy microseconds is
           detected.  Level changes on the GPIO are then reported for actv microseconds after which the  process
           repeats.
           The filter only affects callbacks (including pipe notifications).
           The R/READ, BR1, and BR2 commands are not affected.
           Note,  level  changes  before  and  after  the  active period may be reported.  Your software must be
           designed to cope with such reports.
           Example
           $ pigs fn 7 250 1000
           $ pigs fn 7 2500000 1000
           -125
           ERROR: bad filter parameter
       FO file mode - Open a file in mode
           This function returns a handle to a file file opened in a specified mode mode.
           Upon success a handle (>=0) is returned.  On error a negative status code will be returned.
           File
           A file may only be opened if permission is granted  by  an  entry  in  /opt/pigpio/access.   This  is
           intended to allow remote access to files in a more or less controlled manner.
           Each  entry  in /opt/pigpio/access takes the form of a file path which may contain wildcards followed
           by a single letter permission.  The permission may be R for read, W for write, U for read/write,  and
           N for no access.
           Where  more than one entry matches a file the most specific rule applies.  If no entry matches a file
           then access is denied.
           Suppose /opt/pigpio/access contains the following entries
           /home/* n
           /home/pi/shared/dir_1/* w
           /home/pi/shared/dir_2/* r
           /home/pi/shared/dir_3/* u
           /home/pi/shared/dir_1/file.txt n
           Files may be written in directory dir_1 with the exception of file.txt.
           Files may be read in directory dir_2.
           Files may be read and written in directory dir_3.
           If a directory allows read, write, or read/write access then files may be created in that directory.
           In an attempt to prevent risky permissions the following paths are ignored in /opt/pigpio/access.
           a path containing ..
           a path containing only wildcards (*?)
           a path containing less than two non-wildcard parts
           Mode
           The mode may have the following values.
                   Value   Meaning
           READ      1     open file for reading
           WRITE     2     open file for writing
           RW        3     open file for reading and writing
           The following values may be or'd into the mode.
                    Value   Meaning
           APPEND     4     All writes append data to the end of the file
           CREATE     8     The file is created if it doesn't exist
           TRUNC     16     The file is truncated
           Newly created files are owned by root with permissions owner read and write.
           Example
           $ ls /ram/*.c
           /ram/command.c      /ram/pigpiod.c  /ram/pigs.c
           /ram/x_pigpiod_if.c /ram/pig2vcd.c  /ram/pigpiod_if2.c
           /ram/x_pigpio.c     /ram/x_repeat.c /ram/pigpio.c
           /ram/pigpiod_if.c   /ram/x_pigpiod_if2.c
           # assumes /opt/pigpio/access contains the following line
           # /ram/*.c r
           $ pigs fo /ram/pigpio.c 1
           0
           $ pigs fo /ram/new.c 1
           -128
           ERROR: file open failed
           $ pigs fo /ram/new.c 9
           1
           $ ls /ram/*.c -l
           -rw-r--r-- 1 joan joan  42923 Jul 10 11:22 /ram/command.c
           -rw------- 1 root root      0 Jul 10 16:54 /ram/new.c
           -rw-r--r-- 1 joan joan   2971 Jul 10 11:22 /ram/pig2vcd.c
           -rw------- 1 joan joan 296235 Jul 10 11:22 /ram/pigpio.c
           -rw-r--r-- 1 joan joan   9266 Jul 10 11:22 /ram/pigpiod.c
           -rw-r--r-- 1 joan joan  37331 Jul 10 11:22 /ram/pigpiod_if2.c
           -rw-r--r-- 1 joan joan  33088 Jul 10 11:22 /ram/pigpiod_if.c
           -rw-r--r-- 1 joan joan   7990 Jul 10 11:22 /ram/pigs.c
           -rw-r--r-- 1 joan joan  19970 Jul 10 11:22 /ram/x_pigpio.c
           -rw-r--r-- 1 joan joan  20804 Jul 10 11:22 /ram/x_pigpiod_if2.c
           -rw-r--r-- 1 joan joan  19844 Jul 10 11:22 /ram/x_pigpiod_if.c
           -rw-r--r-- 1 joan joan  19907 Jul 10 11:22 /ram/x_repeat.c
       FR h num - Read bytes from file handle
           This command returns up to num bytes of data read from the file associated with handle h.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           Example
           $ pigs fr 0 10
           5 48 49 128 144 255
           $ pigs fr 0 10
           0
       FS h num from - Seek to file handle position
           This command seeks to a position within the file associated with handle h.
           The  number of bytes to move is num.  Positive offsets move forward, negative offsets backwards.  The
           move start position is determined by from as follows.
               From
           0   start
           1   current position
           2   end
           Upon success the new byte position within the file (>=0) is returned.  On  error  a  negative  status
           code will be returned.
           Example
           $ pigs fs 0 200 0 # Seek to start of file plus 200
           200
           $ pigs fs 0 0 1 # Return current position
           200
           $ pigs fs 0 0 2 # Seek to end of file, return size
           296235
       FW h bvs - Write bytes to file handle
           This command writes bytes bvs to the file associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs fw 0 23 45 67 89
       GDC u - Get GPIO PWM dutycycle
           This command returns the PWM dutycycle in use on GPIO u.
           Upon success the dutycycle is returned.  On error a negative status code will be returned.
           For normal PWM the dutycycle will be out of the defined range for the GPIO (see PRG).
           If a hardware clock is active on the GPIO the reported dutycycle will be 500000 (500k) out of 1000000
           (1M).
           If hardware PWM is active on the GPIO the reported dutycycle will be out of a 1000000 (1M).
           Example
           $ pigs p 4 129
           $ pigs gdc 4
           129
           pigs gdc 5
           -92
           ERROR: GPIO is not in use for PWM
       GPW u - Get GPIO servo pulsewidth
           This command returns the servo pulsewidth in use on GPIO u.
           Upon success the servo pulsewidth is returned.  On error a negative status code will be returned.
           Example
           $ pigs s 4 1235
           $ pigs gpw 4
           1235
           $ pigs gpw 9
           -93
           ERROR: GPIO is not in use for servo pulses
       H/HELP  - Display command help
           This command displays a brief list of the commands and their parameters.
           Example
           $ pigs h
           $ pigs help
       HC g cf - Set hardware clock frequency
           This  command sets the hardware clock associated with GPIO g to frequency cf. Frequencies above 30MHz
           are unlikely to work.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs hc 4 5000 # start a 5 KHz clock on GPIO 4 (clock 0)
           $ pigs hc 5 5000000 # start a 5 MHz clcok on GPIO 5 (clock 1)
           -99
           ERROR: need password to use hardware clock 1
           The same clock is available on multiple GPIO.  The latest frequency setting will be used by all  GPIO
           which share a clock.
           The GPIO must be one of the following.
           4   clock 0  All models
           5   clock 1  All models but A and B (reserved for system use)
           6   clock 2  All models but A and B
           20  clock 0  All models but A and B
           21  clock 1  All models but A and B Rev.2 (reserved for system use)
           32  clock 0  Compute module only
           34  clock 0  Compute module only
           42  clock 1  Compute module only (reserved for system use)
           43  clock 2  Compute module only
           44  clock 1  Compute module only (reserved for system use)
           Access  to  clock  1 is protected by a password as its use will likely crash the Pi.  The password is
           given by or'ing 0x5A000000 with the GPIO number.
       HP g pf pdc - Set hardware PWM frequency and dutycycle
           This command sets the hardware PWM associated with  GPIO  g  to  frequency  pf  with  dutycycle  pdc.
           Frequencies above 30MHz are unlikely to work.
           NOTE: Any waveform started by WVTX, WVTXR, or WVCHA will be cancelled.
           This  function is only valid if the pigpio main clock is PCM.  The main clock defaults to PCM but may
           be overridden when the pigpio daemon is started (option -t).
           Upon success nothing is returned.  On error a negative status code will be returned.
           $ pigs hp 18 100 800000 # 80% dutycycle
           $ pigs hp 19 100 200000 # 20% dutycycle
           $ pigs hp 19 400000000 100000
           -96
           ERROR: invalid hardware PWM frequency
           The same PWM channel is available on multiple GPIO.  The latest frequency and dutycycle setting  will
           be used by all GPIO which share a PWM channel.
           The GPIO must be one of the following.
           12  PWM channel 0  All models but A and B
           13  PWM channel 1  All models but A and B
           18  PWM channel 0  All models
           19  PWM channel 1  All models but A and B
           40  PWM channel 0  Compute module only
           41  PWM channel 1  Compute module only
           45  PWM channel 1  Compute module only
           52  PWM channel 0  Compute module only
           53  PWM channel 1  Compute module only
           The  actual  number of steps beween off and fully on is the integral part of 250M/pf (375M/pf for the
           BCM2711).
           The actual frequency set is 250M/steps (375M/steps for the BCM2711).
           There will only be a million steps for a pf of 250 (375 for the BCM2711). Lower frequencies will have
           more steps and higher frequencies will have fewer steps.  pdc is automatically scaled  to  take  this
           into account.
       HWVER  - Get hardware version
           This command returns the hardware revision of the Pi.
           The hardware revision is found in the last 4 characters on the revision line of /proc/cpuinfo.
           If the hardware revision can not be found or is not a valid hexadecimal number the command returns 0.
           The revision number can be used to determine the assignment of GPIO to pins (see g).
           There are currently three types of board.
           Type 1 boards have hardware revision numbers of 2 and 3.
           Type 2 boards have hardware revision numbers of 4, 5, 6, and 15.
           Type 3 boards have hardware revision numbers of 16 or greater.
           for "Revision : 0002" the command returns 2.
           for "Revision : 000f" the command returns 15.
           for "Revision : 000g" the command returns 0.
           Example
           $ pigs hwver # On a B+
           16
       I2CC h - Close I2C handle
           This command closes an I2C handle h previously opened with I2CO.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs i2cc 0 # First close okay.
           $ pigs i2cc 0 # Second fails.
           -25
           ERROR: unknown handle
       I2CO ib id if - Open I2C bus and device with flags
           This command returns a handle to access device id on I2C bus ib.  The device is opened with flags if.
           Physically  buses  0  and  1  are  available on the Pi.  Higher numbered buses will be available if a
           kernel supported bus multiplexor is being used.
           The GPIO used are given in the following table.
                   SDA   SCL
           I2C 0    0     1
           I2C 1    2     3
           No flags are currently defined.  The parameter if should be 0.
           Upon success the next free handle (>=0) is returned.   On  error  a  negative  status  code  will  be
           returned.
           Example
           $ pigs i2co 1 0x70 0 # Bus 1, device 0x70, flags 0.
           0
           $ pigs i2co 1 0x53 0 # Bus 1, device 0x53, flags 0.
           1
       I2CPC h r wv - smb Process Call: exchange register with word
           This  command writes wv to register r of the I2C device associated with handle h and returns a 16-bit
           word read from the device.
           Upon success a value between 0 and 65535 will be returned.  On error a negative status code  will  be
           returned.
           Example
           $ pigs i2cpc 0 37 43210
           39933
           $ pigs i2cpc 0 256 43210
           ERROR: bad i2c/spi/ser parameter
           -81
       I2CPK h r bvs - smb Block Process Call: exchange data bytes with register
           This  command  writes the data bytes bvs to register r of the I2C device associated with handle h and
           returns a device specific number of bytes.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           Example
           $ pigs i2cpk 0 0 0x11 0x12
           6 0 0 0 0 0 0
       I2CRB h r - smb Read Byte Data: read byte from register
           This command returns a single byte read from register r of the I2C device associated with handle h.
           Upon  success  a  value  between 0 and 255 will be returned.  On error a negative status code will be
           returned.
           Example
           $ pigs i2crb 0 0
           6
       I2CRD h num - i2c Read device
           This command returns num bytes read from the I2C device associated with handle h.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           This  command operates on the raw I2C device.  The maximum value of the parameter num is dependent on
           the I2C drivers and the device itself. pigs imposes a limit of about 8000 bytes.
           Example
           $ pigs i2crd 0 16
           16 6 24 0 0 0 0 0 0 0 0 0 0 0 0 32 78
       I2CRI h r num - smb Read I2C Block Data: read bytes from register
           This command returns num bytes from register r of the I2C device associated with handle h.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           The parameter num may be 1-32.
           Example
           $ pigs i2cri 0 0 16
           16 237 155 155 155 155 155 155 155 155 155 155 155 155 155 155 155
       I2CRK h r - smb Read Block Data: read data from register
           This  command  returns  between 1 and 32 bytes read from register r of the I2C device associated with
           handle h.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           The number of bytes of returned data is specific to the device and register.
           Example
           $ pigs i2crk 0 0
           6 0 0 0 0 0 0
           $ pigs i2crk 0 1
           24 0 0 0 0 0 0 0 0 0 0 0 0 120 222 105 215 128 87 195 217 0 0 0 0
       I2CRS h - smb Read Byte: read byte
           This command returns a single byte read from the I2C device associated with handle h.
           Upon  success  a  value  between 0 and 255 will be returned.  On error a negative status code will be
           returned.
           Example
           $ pigs i2crs 0
           0
       I2CRW h r - smb Read Word Data: read word from register
           This command returns a single 16 bit word read from register r of  the  I2C  device  associated  with
           handle h.
           Upon  success  a value between 0 and 65535 will be returned.  On error a negative status code will be
           returned.
           Example
           $ pigs i2crw 0 0
           6150
       I2CWB h r bv - smb Write Byte Data: write byte to register
           This command writes a single byte bv to register r of the I2C device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs i2cwb 0 10 0x54
       I2CWD h bvs - i2c Write device
           This command writes a block of bytes bvs to the I2C device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The number of bytes which may be written in one transaction is dependent on the I2C drivers  and  the
           device itself.  pigs imposes a limit of about 500 bytes.
           This command operates on the raw I2C device.
           Example
           $ pigs i2cwd 0 0x01 0x02 0x03 0x04
       I2CWI h r bvs - smb Write I2C Block Data
           This command writes between 1 and 32 bytes bvs to register r of the I2C device associated with handle
           h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs i2cwi 0 4 0x01 0x04 0xc0
       I2CWK h r bvs - smb Write Block Data: write data to register
           This command writes between 1 and 32 bytes bvs to register r of the I2C device associated with handle
           h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           pigs i2cwk 0 4 0x01 0x04 0xc0
       I2CWQ h bit - smb Write Quick: write bit
           This command writes a single bit to the I2C device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs i2cwq 0 1
       I2CWS h bv - smb Write Byte: write byte
           This command writes a single byte bv to the I2C device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs i2cws 0 0x12
           $ pigs i2cws 0 0xff
           -82
           ERROR: I2C write failed
       I2CWW h r wv - smb Write Word Data: write word to register
           This command writes a single 16 bit word wv to register r of the I2C device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs i2cww 0 0 0xffff
       I2CZ h bvs - Performs multiple I2C transactions
           This  command executes a sequence of I2C operations.  The operations to be performed are specified by
           the contents of bvs which contains the concatenated command codes and associated data.
           The following command codes are supported:
           Name      Cmd & Data   Meaning
           End       0            No more commands
           Escape    1            Next P is two bytes
           On        2            Switch combined flag on
           Off       3            Switch combined flag off
           Address   4 P          Set I2C address to P
           Flags     5 lsb msb    Set I2C flags to lsb + (msb << 8)
           Read      6 P          Read P bytes of data
           Write     7 P ...      Write P bytes of data
           The address, read, and write commands take a parameter P.  Normally P is one byte  (0-255).   If  the
           command  is  preceded  by  the  Escape  command  then P is two bytes (0-65535, least significant byte
           first).
           The address defaults to that associated with the handle h.  The flags default to 0.  The address  and
           flags maintain their previous value until updated.
           Example
           Set address 0x53, write 0x32, read 6 bytes
           Set address 0x1E, write 0x03, read 6 bytes
           Set address 0x68, write 0x1B, read 8 bytes
           End
           0x04 0x53   0x07 0x01 0x32   0x06 0x06
           0x04 0x1E   0x07 0x01 0x03   0x06 0x06
           0x04 0x68   0x07 0x01 0x1B   0x06 0x08
           0x00
       M/MODES g m - Set GPIO mode
           This command sets GPIO g to mode m, typically input (read) or output (write).
           Upon success nothing is returned.  On error a negative status code will be returned.
           Each  GPIO  can  be  configured to be in one of 8 different modes. The modes are named Input, Output,
           ALT0, ALT1, ALT2, ALT3, ALT4, and ALT5.
           To set the mode use the code for the mode.
           Mode  Input Output ALT0 ALT1 ALT2 ALT3 ALT4 ALT5
           Code      R      W    0    1    2    3    4    5
           Example
           $ pigs m 4 r # Input (read)
           $ pigs m 4 w # Output (write)
           $ pigs m 4 0 # ALT 0
           $ pigs m 4 5 # ALT 5
       MG/MODEG g - Get GPIO mode
           This command returns the current mode of GPIO g.
           Upon success the value of the GPIO mode is returned.   On  error  a  negative  status  code  will  be
           returned.
           Value      0      1    2    3    4    5    6    7
           Mode   Input Output ALT5 ALT4 ALT0 ALT1 ALT2 ALT3
           Example
           $ pigs mg 4
           1
       MICS v - Microseconds delay
           This command delays execution for v microseconds.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The main use of this command is expected to be within Scripts.
           Example
           $ pigs mics 20 # Delay 20 microseconds.
           $ pigs mics 1000000 # Delay 1 second.
           $ pigs mics 2000000
           -64
           ERROR: bad MICS delay (too large)
       MILS v - Milliseconds delay
           This command delays execution for v milliseconds.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs mils 2000 # Delay 2 seconds.
           $ pigs mils 61000
           -65
           ERROR: bad MILS delay (too large)
       NB h bits - Start notification
           This command starts notifications on handle h returned by a prior call to NO.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The notification gets state changes for each GPIO specified by bits.
           Example
           $ pigs nb 0 -1 # Shorthand for GPIO 0-31.
           $ pigs nb 0 0xf0 # Get notifications for GPIO 4-7.
           $ pigs nb 1 0xf
           -25
           ERROR: unknown handle
       NC h - Close notification
           This  command  stops notifications on handle h returned by a prior call to NO and releases the handle
           for reuse.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs nc 0 # First call succeeds.
           $ pigs nc 1 # Second call fails.
           -25
           ERROR: unknown handle
       NO  - Request a notification
           This command requests a free notification handle.
           A notification is a method for being notified of GPIO state changes via a pipe.
           Upon success the command returns a handle greater than or equal to zero.  On error a negative  status
           code will be returned.
           Notifications  for  handle  x will be available at the pipe named /dev/pigpiox (where x is the handle
           number).
           E.g. if the command returns 15 then the notifications must be read from /dev/pigpio15.
           Example
           $ pigs no
           0
       NP h - Pause notification
           This command pauses notifications on handle h returned by a prior call to NO.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Notifications for the handle are suspended until a new NB command is given for the handle.
           Example
           $ pigs np 0
       P/PWM u v - Set GPIO PWM value
           This command starts PWM on GPIO u with dutycycle v.  The dutycycle  varies  from  0  (off)  to  range
           (fully on).  The range defaults to 255.
           Upon success nothing is returned.  On error a negative status code will be returned.
           This  and  the servo functionality use the DMA and PWM or PCM peripherals to control and schedule the
           pulsewidths and dutycycles.
           The PRS command may be used to change the default range of 255.
           Example
           $ pigs p 4 64  # Start PWM on GPIO 4 with 25% dutycycle
           $ pigs p 4 128 # 50%
           $ pigs p 4 192 # 75%
           $ pigs p 4 255 # 100%
       PADG pad - Get pad drive strength
           This command gets the pad drive strength padma in mA.
           Returns the pad drive strength if OK.  On error a negative status code will be returned.
           Pad   GPIO
           0     0-27
           1     28-45
           2     46-53
           Example
           $ pigs padg 0
           8
           $ pigs pads 0 16
           $ pigs padg 0
           16
           pigs padg 3
           -126
           ERROR: bad pad number
       PADS pad padma - Set pad drive strength
           This command sets the pad drive strength padma in mA.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Pad   GPIO
           0     0-27
           1     28-45
           2     46-53
           Example
           $ pigs pads 0 16
           $ pigs padg 0
           16
           $ pigs pads 0 17
           -127
           ERROR: bad pad drive strength
       PARSE t - Validate script
           Validates the text t of a script without storing the script.
           Upon success nothing is returned.  On error a list of detected script errors will be given.
           See Scripts.
           This command may be used to find script syntax faults.
           Example
           $ pigs parse tag 100 w 22 1 mils 200 w 22 0 mils 800 jmp 100
           $ pigs parse tag 0 w 22 1 mills 50 w 22 0 dcr p10 jp 99
           Unknown command: mills
           Unknown command: 50
           Bad parameter to dcr
           Can't resolve tag 99
       PFG u - Get GPIO PWM frequency
           This command returns the PWM frequency in Hz used for GPIO u.
           Upon success the PWM frequency is returned.  On error a negative status code will be returned.
           For normal PWM the frequency will be that defined for the GPIO by PFS.
           If a hardware clock is active on the GPIO the reported frequency will be that set by HC.
           If hardware PWM is active on the GPIO the reported frequency will be that set by HP.
           Example
           $ pigs pfg 4
           800
           $ pigs pfg 34
           ERROR: GPIO not 0-31
           -2
       PFS u v - Set GPIO PWM frequency
           This command sets the PWM frequency v to be used for GPIO u.
           The numerically closest frequency to v will be selected.
           Upon success the new frequency is returned.  On error a negative status code will be returned.
           If PWM is currently active on the GPIO it will be switched off and then back on at the new frequency.
           Each GPIO can be independently set to one of 18 different PWM frequencies.
           The selectable frequencies depend upon the sample rate which may be 1, 2, 4, 5, 8, or 10 microseconds
           (default 5).  The sample rate is set when the pigpio daemon is started.
           The frequencies for each sample rate are:
                                  Hertz
                  1: 40000 20000 10000 8000 5000 4000 2500 2000 1600
                      1250  1000   800  500  400  250  200  100   50
                  2: 20000 10000  5000 4000 2500 2000 1250 1000  800
                       625   500   400  250  200  125  100   50   25
                  4: 10000  5000  2500 2000 1250 1000  625  500  400
                       313   250   200  125  100   63   50   25   13
           sample
            rate
            (us)  5:  8000  4000  2000 1600 1000  800  500  400  320
                       250   200   160  100   80   50   40   20   10
                  8:  5000  2500  1250 1000  625  500  313  250  200
                       156   125   100   63   50   31   25   13    6
                 10:  4000  2000  1000  800  500  400  250  200  160
                       125   100    80   50   40   25   20   10    5
           Example
           pigs pfs 4 0 # 0 selects the lowest frequency.
           10
           $ pigs pfs 4 1000 # Set 1000Hz PWM.
           1000
           $ pigs pfs 4 100000 # Very big number selects the highest frequency.
           8000
       PIGPV  - Get pigpio library version
           This command returns the pigpio library version.
           Example
           $ pigs pigpv
           17
       PRG u - Get GPIO PWM range
           This command returns the dutycycle range for GPIO u.
           Upon success the range is returned.  On error a negative status code will be returned.
           If a hardware clock or hardware PWM is active on the GPIO the reported range will be 1000000 (1M).
           Example
           $ pigs prg 4
           255
       PROC t - Store script
           This command stores a script t for later execution.
           If the script is valid a script id (>=0) is returned which is passed to the other script commands. On
           error a negative status code will be returned.
           See Scripts.
           Example
           $ pigs proc tag 123 w 4 0 mils 200 w 4 1 mils 300 dcr p0 jp 123
           0
           $ pigs proc tag 123 w 4 0 mils 5 w 4 1 mils 5 jmp 12
           ERROR: script has unresolved tag
           -63
       PROCD sid - Delete script
           This command deletes script sid.
           Upon success nothing is returned.  On error a negative status code will be returned.
           See Scripts.
           Example
           $ pigs procd 1
           $ pigs procd 1
           ERROR: unknown script id
           -48
       PROCP sid - Get script status and parameters
           This command returns the status of script sid as well as the current value of its 10 parameters.
           Upon success the script status and parameters are  returned.  On error a negative status code will be
           returned.
           The script status may be one of
           0   being initialised
           1   halted
           2   running
           3   waiting
           4   failed
           See Scripts.
           Example
           $ pigs procp 0
           1 0 0 0 0 0 0 0 0 0 0
       PROCR sid pars - Run script
           This command runs stored script sid passing it up to 10 optional parameters.
           Upon success nothing is returned.  On error a negative status code will be returned.
           See Scripts.
           Example
           $ pigs proc tag 123 w 4 0 mils 200 w 4 1 mils 300 dcr p0 jp 123
           0
           $ pigs procr 0 50 # Run script 0 with parameter 0 of 50.
           $ pigs procp 0
           2 44 0 0 0 0 0 0 0 0 0
           $ pigs procp 0
           2 37 0 0 0 0 0 0 0 0 0
           $ pigs procp 0
           2 10 0 0 0 0 0 0 0 0 0
           $ pigs procp 0
           2 5 0 0 0 0 0 0 0 0 0
           $ pigs procp 0
           2 2 0 0 0 0 0 0 0 0 0
           $ pigs procp 0
           1 -1 0 0 0 0 0 0 0 0 0
       PROCS sid - Stop script
           This command stops a running script sid.
           Upon success nothing is returned.  On error a negative status code will be returned.
           See Scripts.
           Example
           $ pigs procs 0
           $ pigs procs 1
           -48
           ERROR: unknown script id
       PROCU sid pars - Set script parameters
           This command sets the parameters of a stored script sid passing it up to 10 parameters.
           Upon success nothing is returned.  On error a negative status code will be returned.
           See Scripts.
           Example
           $ pigs proc tag 0 hp 18 p0 p1 mils 1000 jmp 0
           0
           $ pigs procu 0 50 500000
           $ pigs procr 0
           $ pigs procu 0 100
           $ pigs procu 0 200
           $ pigs procu 0 200 100000
       PRRG u - Get GPIO PWM real range
           This command returns the real underlying range used by GPIO u.
           If a hardware clock is active on the GPIO the reported real range will be 1000000 (1M).
           If hardware PWM is active on the GPIO the reported real range will be approximately 250M  divided  by
           the set PWM frequency.
           On error a negative status code will be returned.
           See PRS.
           Example
           $ pigs prrg 17
           250
           $ pigs pfs 17 0
           10
           $ pigs prrg 17
           20000
           $ pigs pfs 17 100000
           8000
           $ pigs prrg 17
           25
       PRS u v - Set GPIO PWM range
           This command sets the dutycycle range v to be used for GPIO u.  Subsequent uses of command P/PWM will
           use a dutycycle between 0 (off) and v (fully on).
           Upon success the real underlying range used by the GPIO is returned.  On error a negative status code
           will be returned.
           If PWM is currently active on the GPIO its dutycycle will be scaled to reflect the new range.
           The  real  range,  the number of steps between fully off and fully on for each frequency, is given in
           the following table.
            #1   #2   #3   #4   #5   #6   #7    #8    #9
            25   50  100  125  200  250  400   500   625
           #10  #11  #12  #13  #14  #15  #16   #17   #18
           800 1000 1250 2000 2500 4000 5000 10000 20000
           The real value set by PRS is (dutycycle * real range) / range.
           See PRRG
           Example
           $ pigs prs 18 1000
           250
       PUD g p - Set GPIO pull up/down
           This command sets the internal pull/up down for GPIO g to mode p.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The mode may be pull-down (D), pull-up (U), or off (O).
           Example
           $ pigs pud 4 d # Set pull-down on GPIO 4.
           $ pigs pud 4 u # Set pull-up on GPIO 4.
           $ pigs pud 4 o # No pull-up/down on GPIO 4.
       R/READ g - Read GPIO level
           This reads the current level of GPIO g.
           Upon success the current level is returned.  On error a negative status code will be returned.
           Example
           $ pigs r 17 # Get level of GPIO 17.
           0
           $ pigs r 4 # Get level of GPIO 4.
           1
       S/SERVO u v - Set GPIO servo pulsewidth
           This command starts servo pulses of v microseconds on GPIO u.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The servo pulsewidth may be 0 (off), 500 (most anti-clockwise) to 2500 (most clockwise).
           The range supported by servos varies and should  probably  be  determined  by  experiment.  Generally
           values  between  1000-2000  should be safe.  A value of 1500 should always be safe and represents the
           mid-point of rotation.
           You can DAMAGE a servo if you command it to move beyond its limits.
           Example
           $ pigs SERVO 17 1500
           This example causes an on pulse of 1500 microseconds duration to be transmitted on GPIO 17 at a  rate
           of 50 times per second.
           This will command a servo connected to GPIO 17 to rotate to its mid-point.
           Example
           pigs s 17 0 # Switch servo pulses off.
       SERC h - Close serial handle
           This command closes a serial handle h previously opened with SERO.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs serc 0 # First close okay.
           $ pigs serc 0 # Second close gives error.
           -25
           ERROR: unknown handle
       SERDA h - Check for serial data ready to read
           This  command  returns  the  number  of  bytes  of  data  available to be read from the serial device
           associated with handle h.
           Upon success the count of bytes available to be read is returned  (which  may  be  0).   On  error  a
           negative status code will be returned.
           Example
           $ pigs serda 0
           0
       SERO dev b sef - Open serial device dev at baud b with flags
           This command opens the serial dev at b bits per second.
           No flags are currently defined.  sef should be set to zero.
           Upon success a handle (>=0) is returned.  On error a negative status code will be returned.
           The device name must start with /dev/tty or /dev/serial.
           The  baud  rate  must  be  one of 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600,
           19200, 38400, 57600, 115200, or 230400.
           Example
           $ pigs sero /dev/ttyAMA0 9600 0
           0
           $ pigs sero /dev/tty1 38400 0
           1
       SERR h num - Read bytes from serial handle
           This command returns up to num bytes of data read from the serial device associated with handle h.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           Example
           $ pigs serr 0 10
           5 48 49 128 144 255
           $ pigs serr 0 10
           0
       SERRB  - Read byte from serial handle
           This command returns a byte of data read from the serial device associated with handle h.
           Upon  success  a  number  between  0  and  255  is returned.  On error a negative status code will be
           returned.
           Example
           $ pigs serrb 0
           23
           $ pigs serrb 0
           45
       SERW h bvs - Write bytes to serial handle
           This command writes bytes bvs to the serial device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs serw 0 23 45 67 89
       SERWB h bv - Write byte to serial handle
           This command writes a single byte bv to the serial device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs serwb 0 23
           $ pigs serwb 0 0xf0
       SHELL name str - Execute a shell command
           This command uses the system call to execute a shell script name with the given  string  str  as  its
           parameter.
           The exit status of the system call is returned if OK, otherwise PI_BAD_SHELL_STATUS.
           name must exist in /opt/pigpio/cgi and must be executable.
           The  returned  exit  status is normally 256 times that set by the shell script exit function.  If the
           script can't be found 32512 will be returned.
           The following table gives some example returned statuses.
           Script exit status   Returned system call status
           1                    256
           5                    1280
           10                   2560
           200                  51200
           script not found     32512
           Example
           # pass two parameters, hello and world
           $ pigs shell scr1 hello world
           256
           # pass three parameters, hello, string with spaces, and world
           $ pigs shell scr1 "hello 'string with spaces' world"
           256
           # pass one parameter, hello string with spaces world
           $ pigs shell scr1 "
           256
           # non-existent script
           $ pigs shell scr78 par1
           32512
       SLR u num - Read bit bang serial data from GPIO
           This command returns up to num bytes of bit bang serial data read from GPIO u.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           The GPIO u should have been initialised with the SLRO command.
           The  bytes  returned  for each character depend upon the number of data bits db specified in the SLRO
           command.
           For db 1-8 there will be one byte per character.
           For db 9-16 there will be two bytes per character.
           For db 17-32 there will be four bytes per character.
           Example
           $ pigs slr 15 20
           6 1 0 23 45 89 0
       SLRC u - Close GPIO for bit bang serial data
           This command closes GPIO u for reading bit bang serial data.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs slrc 23
           $ pigs slrc 23
           -38
           ERROR: no serial read in progress on GPIO
       SLRI u v - Sets bit bang serial data logic levels
           This command sets the logic level for reading bit bang serial data on GPIO u.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The invert parameter v is 1 for inverted signal, 0 for normal.
           Example
           $ pigs slri 17 1 # invert logic on GPIO 17
           $ pigs slri 23 0 # use normal logic on GPIO 23
       SLRO u b db - Open GPIO for bit bang serial data
           This command opens GPIO u for reading bit bang serial data at b baud and db data bits.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The baud rate may be between 50 and 250000 bits per second.
           The received data is held in a cyclic buffer.
           It is the user's responsibility to read the data (with SLR) in a timely fashion.
           Example
           $ pigs slro 23 19200 8
           $ pigs slro 23 19200 8
           -50
           ERROR: GPIO already in use
       SPIC h - SPI close handle
           This command closes the SPI handle h returned by a prior call to SPIO.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs spic 1
           $ pigs spic 1
           -25
           ERROR: unknown handle
       SPIO c b spf - SPI open channel at baud b with flags
           This command returns a handle to a SPI device on channel c.
           Data will be transferred at b bits per second.  The flags spf may  be  used  to  modify  the  default
           behaviour of 4-wire operation, mode 0, active low chip select.
           Speeds between 32kbps and 125Mbps are allowed.  Speeds above 30Mbps are unlikely to work.
           The Pi has two SPI peripherals: main and auxiliary.
           The main SPI has two chip selects (channels), the auxiliary has three.
           The auxiliary SPI is available on all models but the A and B.
           The GPIO used are given in the following table.
                      MISO   MOSI   SCLK   CE0   CE1   CE2
           Main SPI      9     10     11     8     7     -
           Aux SPI      19     20     21    18    17    16
           The flags consists of the least significant 22 bits.
           21 20 19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
            b  b  b  b  b  b  R  T  n  n  n  n  W  A u2 u1 u0 p2 p1 p0  m  m
           mm defines the SPI mode.
           Warning:  modes 1 and 3 do not appear to work on the auxiliary SPI.
           Mode POL PHA
            0    0   0
            1    0   1
            2    1   0
            3    1   1
           px is 0 if CEx is active low (default) and 1 for active high.
           ux is 0 if the CEx GPIO is reserved for SPI (default) and 1 otherwise.
           A is 0 for the main SPI, 1 for the auxiliary SPI.
           W is 0 if the device is not 3-wire, 1 if the device is 3-wire.  Main SPI only.
           nnnn defines the number of bytes (0-15) to write before switching the MOSI line to MISO to read data.
           This field is ignored if W is not set.  Main SPI only.
           T  is  1  if  the least significant bit is transmitted on MOSI first, the default (0) shifts the most
           significant bit out first.  Auxiliary SPI only.
           R is 1 if the least significant bit is received on MISO first, the  default  (0)  receives  the  most
           significant bit first.  Auxiliary SPI only.
           bbbbbb  defines  the  word size in bits (0-32).  The default (0) sets 8 bits per word.  Auxiliary SPI
           only.
           The SPIR, SPIW, and SPIX commands transfer data packed into 1, 2, or 4 bytes according  to  the  word
           size in bits.
           For bits 1-8 there will be one byte per character.
           For bits 9-16 there will be two bytes per character.
           For bits 17-32 there will be four bytes per character.
           Multi-byte transfers are made in least significant byte first order.
           E.g. to transfer 32 11-bit words 64 bytes need to be sent.
           E.g. to transfer the 14 bit value 0x1ABC send the bytes 0xBC followed by 0x1A.
           The other bits in flags should be set to zero.
           Upon success a handle (>=0) is returned.  On error a negative status code will be returned.
           Example
           $ pigs spio 0 100000 3 # Open channel 0 at 100kbps in mode 3.
           0
           $ pigs spio 0 32000 256 # Open channel 0 of auxiliary spi at 32kbps.
           1
       SPIR h num - SPI read bytes from handle
           This command returns num bytes read from the SPI device associated with handle h.
           Upon  success  the  count of returned bytes followed by the bytes themselves is returned.  On error a
           negative status code will be returned.
           Example
           $ pigs spir 0 10 # Read 10 bytes from the SPI device.
           10 0 0 0 0 0 0 0 0 0 0
       SPIW h bvs - SPI write bytes to handle
           This command writes bytes bvs to the SPI device associated with handle h.
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs spiw 0 0x22 0x33 0xcc 0xff
       SPIX h bvs - SPI transfer bytes to handle
           This command writes bytes bvs to the SPI device associated with handle h.  It returns the same number
           of bytes read from the device.
           Upon success the count of returned bytes followed by the bytes themselves is returned.   On  error  a
           negative status code will be returned.
           Example
           $ pigs spix 0 0x22 0x33 0xcc 0xff
           4 0 0 0 0
       T/TICK  - Get current tick
           This command returns the current system tick.
           Tick is the number of microseconds since system boot.
           As  tick  is  an  unsigned  32  bit  quantity  it  wraps  around  after  2^32  microseconds, which is
           approximately 1 hour 12 minutes.
           Example
           $ pigs t mils 1000 t
           3691823946
           3692833987
       TRIG u pl L - Send a trigger pulse
           This command sends a trigger pulse of pl microseconds at level L to GPIO u.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The GPIO is set to not level at the end of the pulse.
           Example
           $ pigs trig 4 10 1
           $ pigs trig 4 51 1
           -46
           ERROR: trigger pulse > 50 microseconds
       W/WRITE g L - Write GPIO level
           This command sets GPIO g to level L.  The level may be 0 (low, off, clear) or 1 (high, on, set).
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs w 23 0
           $ pigs w 23 1
           $ pigs w 23 2
           -5
           ERROR: level not 0-1
       WDOG u v - Set GPIO watchdog
           This command sets a watchdog of v milliseconds on GPIO u.
           Upon success nothing is returned.  On error a negative status code will be returned.
           The watchdog is nominally in milliseconds.
           One watchdog may be registered per GPIO.
           The watchdog may be cancelled by setting timeout to 0.
           Once a watchdog has been started monitors of the GPIO will be triggered every timeout interval  after
           the last GPIO activity.  The watchdog expiry will be indicated by a special TIMEOUT value.
           Example
           $ pigs wdog 23 90000
           -15
           ERROR: timeout not 0-60000
           $ pigs wdog 23 9000
           This  example  causes  a report to be written to any notification pipes listening on GPIO 23 whenever
           GPIO 23 changes state or approximately every 9000 ms.
       WVAG trips - Add generic pulses to waveform
           This command adds 1 one or more triplets trips of GPIO on, GPIO off, delay to the  existing  waveform
           (if any).
           Upon  success  the  total  number  of pulses in the waveform so far is returned.  On error a negative
           status code will be returned.
           The triplets will be added at the start of the existing waveform.  If they are to start  offset  from
           the start then the first triplet should consist solely of a delay i.e. 0 0 offset.
           Example
           $ pigs wvag 0x10 0x80 1000 0x80 0x10 9000
           2
           $ pigs wvag 0 0 10000 0x10 0x80 1000 0x80 0x10 9000
           4
       WVAS u b db sb o bvs - Add serial data to waveform
           This  command  adds  a  waveform  representing  serial  data  bvs to GPIO u at b baud to the existing
           waveform (if any).  The serial data starts o microseconds from the start of the waveform.
           Upon success the total number of pulses in the waveform so far is  returned.   On  error  a  negative
           status code will be returned.
           The serial data is formatted as one start bit, db data bits, and sb/2 stop bits.
           The baud rate may be between 50 and 1000000 bits per second.
           It is legal to add serial data streams with different baud rates to the same waveform.
           The bytes required for each character depend upon db.
           For db 1-8 there will be one byte per character.
           For db 9-16 there will be two bytes per character.
           For db 17-32 there will be four bytes per character.
           Example
           $ pigs wvas 4 9600 8 2 0 0x30 0x31 0x32 0x33
           23
           $ pigs wvas 7 38400 8 2 0 0x41 0x42
           35
       WVTAT  - Returns the current transmitting waveform
           This  command  returns  the  id  of  the waveform currently being transmitted.  Chained waves are not
           supported.
           Returns the waveform id or one of the following special values:
           9998 - transmitted wave not found
           9999 - no wave being transmitted
           Example
           $ pigs wvtat
           9999
       WVBSY  - Check if waveform is being transmitted
           This command checks to see if a waveform is currently being transmitted.
           Returns 1 if a waveform is currently being transmitted, otherwise 0.
           Example
           $ pigs wvbsy
           0
       WVCHA bvs - Transmits a chain of waveforms
           This command transmits a chain of waveforms.
           NOTE: Any hardware PWM started by HP will be cancelled.
           The waves to be transmitted are specified by the contents of bvs which contains an  ordered  list  of
           wave_ids and optional command codes and related data.
           Upon success 0 is returned.  On error a negative status code will be returned.
           Each wave is transmitted in the order specified.  A wave may occur multiple times per chain.
           A  blocks  of  waves  may  be  transmitted  multiple  times  by using the loop commands. The block is
           bracketed by loop start and end commands.  Loops may be nested.
           Delays between waves may be added with the delay command.
           The following command codes are supported:
           Name           Cmd & Data   Meaning
           Loop Start     255 0        Identify start of a wave block
           Loop Repeat    255 1 x y    loop x + y*256 times
           Delay          255 2 x y    delay x + y*256 microseconds
           Loop Forever   255 3        loop forever
           If present Loop Forever must be the last entry in the chain.
           The code is currently dimensioned to support a chain with roughly 600 entries and 20 loop counters.
           Example
           #!/bin/bash
           GPIO=4
           WAVES=5
           pigs m $GPIO w
           for ((i=0; i<$WAVES; i++))
           do
              pigs wvag $((1<<GPIO)) 0 20 0 $((1<<GPIO)) $(((i+1)*200))
              w[i]=$(pigs wvcre)
           done
           # transmit waves 4+3+2
           # loop start
           #    transmit waves 0+0+0
           #    loop start
           #       transmit waves 0+1
           #       delay 5000us
           #    loop end (repeat 30 times)
           #    loop start
           #       transmit waves 2+3+0
           #       transmit waves 3+1+2
           #    loop end (repeat 10 times)
           # loop end (repeat 5 times)
           # transmit waves 4+4+4
           # delay 20000us
           # transmit waves 0+0+0
           pigs wvcha .br
              ${w[4]} ${w[3]} ${w[2]} .br
              255 0 .br
                 ${w[0]} ${w[0]} ${w[0]} .br
                 255 0 .br
                    ${w[0]} ${w[1]} .br
                    255 2 0x88 0x13 .br
                 255 1 30 0 .br
                 255 0 .br
                    ${w[2]} ${w[3]} ${w[0]} .br
                    ${w[3]} ${w[1]} ${w[2]} .br
                 255 1 10 0 .br
              255 1 5 0 .br
              ${w[4]} ${w[4]} ${w[4]} .br
              255 2 0x20 0x4E .br
              ${w[0]} ${w[0]} ${w[0]}
           while [[ $(pigs wvbsy) -eq 1 ]]; do sleep 0.1; done
           for ((i=0; i<$WAVES; i++)); do echo ${w[i]}; pigs wvdel ${w[i]}; done
       WVCLR  - Clear all waveforms
           This command clears all waveforms.
           Nothing is returned.
           Example
           $ pigs wvclr
       WVCRE  - Create a waveform
           This command creates a waveform from the data provided by the  prior  calls  to  the  WVAG  and  WVAS
           commands.
           Upon success a wave id (>=0) is returned.  On error a negative status code will be returned.
           The data provided by the WVAG and WVAS commands is consumed by this command.
           As many waveforms may be created as there is space available.  The wave id is passed to WVTX or WVTXR
           to specify the waveform to transmit.
           Normal usage would be
           Step 1. WVCLR to clear all waveforms and added data.
           Step 2. WVAG/WVAS calls to supply the waveform data.
           Step 3. WVCRE to create the waveform and get a unique id.
           Repeat steps 2 and 3 as needed.
           Step 4. WVTX or WVTXR with the id of the waveform to transmit.
           A waveform comprises of one or more pulses.
           A pulse specifies
           1) the GPIO to be switched on at the start of the pulse.
           2) the GPIO to be switched off at the start of the pulse.
           3) the delay in microseconds before the next pulse.
           Any  or  all  the  fields  can be zero.  It doesn't make any sense to set all the fields to zero (the
           pulse will be ignored).
           When a waveform is started each pulse is executed in order with the specified delay between the pulse
           and the next.
           Example
           $ pigs wvas 4 9600 0 23 45 67 89 90
           37
           $ pigs wvcre
           0
           $ pigs wvcre
           -69
           ERROR: attempt to create an empty waveform
       WVCAP percent - Create a waveform of fixed size
           Create a waveform of fixed size. Similar to WVCRE, this command  creates  a  waveform  but  pads  the
           consumed  resources  to  a fixed size, specified as a percent of the total resources. Padded waves of
           equal size can be re-cycled efficiently allowing newly created  waves  to  re-use  the  resources  of
           deleted waves of the same dimension.
           Upon success a wave id (>=0) is returned. On error a negative status code will be returned.
           The data provided by the WVAG and WVAS commands are consumed by this command.
           As  many waveforms may be created as there is space available. The wave id is passed to WVTX or WVTXR
           to specify the waveform to transmit.
           Normal usage would be
           Step 1. WVCLR to clear all waveforms and added data.
           Step 2. WVAG/WVAS calls to supply the waveform data.
           Step 3. WVCAP to create a waveform of a uniform size.
           Step 4. WVTX or WVTXR with the id of the waveform to transmit.
           Repeat steps 2 - 4 as needed.
           Step 5. Any wave id can now be deleted and another wave of the same size can be created in its place.
           Example
           Example
           # Create a wave that consumes 50% of the total resource:
           $ pigs wvag 16 0 5000000 0 16 5000000
           2
           $ pigs wvcap 50
           0
           $ pigs wvtx 0
           11918
       WVDEL wid - Delete selected waveform
           This command deletes the waveform with id wid.
           The wave is flagged for deletion.  The resources used by the wave will only be reused when either  of
           the following apply.
           - all waves with higher numbered wave ids have been deleted or have been flagged for deletion.
           -  a  new wave is created which uses exactly the same resources as the current wave (see the C source
           for gpioWaveCreate for details).
           Upon success nothing is returned.  On error a negative status code will be returned.
           Example
           $ pigs wvdel 0
           $ pigs wvdel 0
           -66
           ERROR: non existent wave id
       WVHLT  - Stop waveform
           This command aborts the transmission of the current waveform.
           Nothing is returned.
           This command is intended to stop a waveform started in the repeat mode.
           Example
           $ pigs wvhlt
       WVNEW  - Initialise a new waveform
           This clears any existing waveform data ready for the creation of a new waveform.
           Nothing is returned.
           Example
           $ pigs wvnew
       WVSC ws - Get waveform DMA CB stats
           The statistic requested by ws is returned.
           ws identifies the subcommand as follows.
           0 Get Cbs
           1 Get High Cbs
           2 Get Max Cbs
           Example
           $ pigs wvas 4 9600 0 23 45 67 89 90
           37
           $ pigs wvsc 0
           74
           $ pigs wvsc 1
           74
           $ pigs wvsc 2
           25016
       WVSM ws - Get waveform time stats
           The statistic requested by ws is returned.
           ws identifies the subcommand as follows.
           0 Get Micros
           1 Get High Micros
           2 Get Max Micros
           Example
           $ pigs wvsm 0
           5314
           $ pigs wvsm 1
           5314
           $ pigs wvsm 2
           1800000000
       WVSP ws - Get waveform pulse stats
           The statistic requested by ws is returned.
           ws identifies the subcommand as follows.
           0 Get Pulses
           1 Get High Pulses
           2 Get Max Pulses
           Example
           $ pigs wvsp 0
           37
           $ pigs wvsp 1
           37
           $ pigs wvsp 2
           12000
       WVTX wid - Transmits waveform once
           This command transmits the waveform with id wid once.
           NOTE: Any hardware PWM started by HP will be cancelled.
           Upon success the number of DMA control blocks in the waveform  is  returned.   On  error  a  negative
           status code will be returned.
           Example
           $ pigs wvtx 1
           75
           $ pigs wvtx 2
           -66
           ERROR: non existent wave id
       WVTXM wid wmde - Transmits waveform using mode
           This command transmits the waveform with id wid using mode wmde.
           The  mode may be send once (0), send repeatedly (1), send once but first sync with previous wave (2),
           or send repeatedly but first sync with previous wave (3).
           WARNING: bad things may happen if you delete the previous waveform before it has been synced  to  the
           new waveform.
           NOTE: Any hardware PWM started by HP will be cancelled.
           Upon  success  the  number  of  DMA  control blocks in the waveform is returned.  On error a negative
           status code will be returned.
           Example
           $ pigs wvtxm 1 3
           75
           $ pigs wvtxm 2 0
           -66
           ERROR: non existent wave id
       WVTXR wid - Transmits waveform repeatedly
           This command transmits the waveform with id wid repeatedly.
           NOTE: Any hardware PWM started by HP will be cancelled.
           Upon success the number of DMA control blocks in the waveform  is  returned.   On  error  a  negative
           status code will be returned.
           Example
           $ pigs wvtxr 1
           75
           $ pigs wvtxr 2
           -66
           ERROR: non existent wave id
PARAMETERS
       actv - 0-1000000
       The number of microseconds level changes are reported for once a noise filter has been triggered (by stdy
       microseconds of a stable level).
       b - baud
       The  command expects the baud rate in bits per second for the transmission of serial data (I2C/SPI/serial
       link, waves).
       bctl - BSC control word
       The command expects a BSC control word, see BSCX.
       bit - bit value (0-1)
       The command expects 0 or 1.
       bits - a bit mask
       A mask is used to select one or more GPIO.  A GPIO is selected if bit (1<<GPIO) is set in the mask.
       E.g. a mask of 6 (binary 110) select GPIO 1 and 2, a mask of 0x103 (binary 100000011) selects GPIO 0,  1,
       and 8.
       bv - a byte value (0-255)
       The command expects a byte value.
       bvs - byte values (0-255)
       The command expects one or more byte values.
       c - SPI channel (0-1)
       The command expects a SPI channel.
       cf - hardware clock frequency (4689-250M, 13184-375M for the BCM2711)
       The command expects a frequency.
       cs - GPIO (0-31)
       The GPIO used for the slave select signal when bit banging SPI.
       db - serial data bits (1-32)
       The command expects the number of data bits per serial character.
       dev - a tty serial device (/dev/tty* or /dev/serial*)
       The command expects the name of a tty serial device, e.g.
       /dev/ttyAMA0
       /dev/ttyUSB0
       /dev/tty0
       /dev/serial0
       event - 0-31
       An event is a signal used to inform one or more consumers to start an action.
       file - a file name
       The file name must match an entry in /opt/pigpio/access.
       from - 0-2
       Position to seek from FS.
           From
       0   start
       1   current position
       2   end
       g - GPIO (0-53)
       The command expects a GPIO.
       There are 54 General Purpose Input Outputs (GPIO) named gpio0 through gpio53.
       They  are  split  into  two  banks.   Bank 1 consists of gpio0 through gpio31.  Bank 2 consists of gpio32
       through gpio53.
       All the GPIO which are safe for the user to read and write are in bank 1.  Not all GPIO  in  bank  1  are
       safe though. Type 1 boards have 17 safe GPIO.  Type 2 boards have 21. Type 3 boards have 26.
       See HWVER.
       The user GPIO are marked with an X in the following table.
                 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
       Type 1    X  X  -  -  X  -  -  X  X  X  X  X  -  -  X  X
       Type 2    -  -  X  X  X  -  -  X  X  X  X  X  -  -  X  X
       Type 3          X  X  X  X  X  X  X  X  X  X  X  X  X  X
                16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
       Type 1    -  X  X  -  -  X  X  X  X  X  -  -  -  -  -  -
       Type 2    -  X  X  -  -  -  X  X  X  X  -  X  X  X  X  X
       Type 3    X  X  X  X  X  X  X  X  X  X  X  X  -  -  -  -
       You are not prevented from writing to unsafe GPIO.  The consequences of doing so range from no effect, to
       a crash, or corrupted data.
       h - handle (>=0)
       The command expects a handle.
       A handle is a number referencing an object opened by one of FO, I2CO, NO, SERO, SPIO.
       ib - I2C bus (>=0)
       The command expects an I2C bus number.
       id - I2C device (0-0x7F)
       The command expects the address of an I2C device.
       if - I2C flags (0)
       The command expects an I2C flags value.  No flags are currently defined.
       L - level (0-1)
       The command expects a GPIO level.
       m - mode (RW540123)
       The command expects a mode character.
       Each  GPIO  can be configured to be in one of 8 different modes. The modes are named Input, Output, ALT0,
       ALT1, ALT2, ALT3, ALT4, and ALT5.
       To set the mode use the code for the mode.
       The value is returned by the mode get command.
       Mode    Input   Output   ALT0   ALT1   ALT2   ALT3   ALT4   ALT5
       Code      R        W       0      1      2      3      4      5
       Value     0        1       4      5      6      7      3      2
       miso - GPIO (0-31)
       The GPIO used for the MISO signal when bit banging SPI.
       mode - file open mode
       One of the following values.
               Value   Meaning
       READ      1     open file for reading
       WRITE     2     open file for writing
       RW        3     open file for reading and writing
       The following values can be or'd into the mode.
                Value   Meaning
       APPEND   4       All writes append data to the end of the file
       CREATE   8       The file is created if it doesn't exist
       TRUNC    16      The file is truncated
       mosi - GPIO (0-31)
       The GPIO used for the MOSI signal when bit banging SPI.
       name - the name of a script
       Only alphanumeric characters, '-' and '_' are allowed in the name.
       num - maximum number of bytes to return (1-)
       The command expects the maximum number of bytes to return.
       For the I2C and SPI commands the requested number of bytes will always be returned.
       For the serial and file commands the smaller of the number of bytes available to be read  (which  may  be
       zero) and num bytes will be returned.
       o - offset (>=0)
       Serial data is stored offset microseconds from the start of the waveform.
       p - PUD (ODU)
       The command expects a PUD character.
       Each  GPIO can be configured to use or not use an internal pull up or pull down resistor.  This is useful
       to provide a default state for inputs.
       A pull up will default the input to 1 (high).
       A pull down will default the input to 0 (low).
       To set the pull up down state use the command character for the state.
       Pull Up Down      Off Pull Down Pull Up
       Command Character   O         D       U
       There is no mechanism to read the pull up down state.
       pad - 0-2
       A set of GPIO which share common drivers.
       Pad   GPIO
       0     0-27
       1     28-45
       2     46-53
       padma - 1-16
       The mA which may be drawn from each GPIO whilst still guaranteeing the high and low levels.
       pars - script parameters
       The command expects 0 to 10 numbers as parameters to be passed to the script.
       pat - a file name pattern
       A file  path  which  may  contain  wildcards.   To  be  accessible  the  path  must  match  an  entry  in
       /opt/pigpio/access.
       pdc - hardware PWM dutycycle (0-1000000)
       The command expects a dutycycle.
       percent - percent (1-100)
       The  percent of wave resources to allocate to a wave.  It can be useful to create waves of fixed sizes to
       prevent wave fragmentation (where there are plenty of resources but not a large enough contiguous space).
       pf - hardware PWM frequency (1-125M, 1-187.5M for the BCM2711)
       The command expects a frequency.
       pl - pulse length (1-100)
       The command expects a pulse length in microseconds.
       r - register (0-255)
       The command expects an I2C register number.
       sb - serial stop (half) bits (2-8)
       The command expects the number of stop (half) bits per serial character.
       scl - user GPIO (0-31)
       The command expects the number of the GPIO to be used for SCL when bit banging I2C.
       sclk - user GPIO (0-31)
       The GPIO used for the SCLK signal when bit banging SPI.
       sda - user GPIO (0-31)
       The command expects the number of the GPIO to be used for SDA when bit banging I2C.
       sef - serial flags (32 bits)
       The command expects a flag value.  No serial flags are currently defined.
       sid - script id (>= 0)
       The command expects a script id as returned by a call to PROC.
       spf - SPI flags (32 bits)
       See SPIO and BSPIO.
       stdy - 0-300000
       The number of microseconds level changes must be stable for before reporting the level  changed  (FG)  or
       triggering the active part of a noise filter (FN).
       str - a string
       The command expects a string.
       t - a string
       The command expects a string.
       trips - triplets
       The command expects 1 or more triplets of GPIO on, GPIO off, delay.
       E.g. 0x400000 0 100000 0 0x400000 900000 defines two pulses as follows
            GPIO on           GPIO off           delay
       0x400000 (GPIO 22)           0 (None) 100000 (1/10th s)
                 0 (None) 0x400000 (GPIO 22) 900000 (9/10th s)
       u - user GPIO (0-31)
       The command expects the number of a user GPIO.
       A number of commands are restricted to GPIO in bank 1, in particular the PWM commands, the servo command,
       the watchdog command, and the notification command.
       It is your responsibility to ensure that the PWM and servo commands are only used on safe GPIO.
       See g
       uvs - values
       The  command  expects an arbitrary number of >=0 values (possibly none).  Any after the first two must be
       <= 255.
       v - value
       The command expects a number.
       wid - wave id (>=0)
       The command expects a wave id.
       When a waveform is created it is given an id (0, 1, 2, ...).
       wmde - mode (0-3)
       The command expects a wave transmission mode.
       0 = send once
       1 = send repeatedly
       2 = send once but first sync with previous wave
       3 = send repeatedly but first sync with previous wave
       ws - wave stats sucommand (0-2)
       The command expects a subcommand.
       0 = current value.
       1 = highest value so far.
       2 = maximum possible value.
       wv - word value (0-65535)
       The command expects a word value.
SCRIPTS
       Scripts are programs to be stored and executed by the pigpio daemon.  They are intended to  mitigate  any
       performance problems associated with the pigpio daemon server/client model.
   Example
       A trivial example might be useful.  Suppose you want to toggle a GPIO on and off as fast as possible.
       From the command line you could write
       for ((i=0; i<1000;i++)); do pigs w 22 1 w 22 0; done
       Timing that you will see it takes about 14 seconds, or roughly 70 toggles per second.
       Using the pigpio Python module you could use code such as
       #!/usr/bin/env python
       import time
       import pigpio
       PIN=4
       TOGGLE=10000
       pi = pigpio.pi() # Connect to local Pi.
       s = time.time()
       for i in range(TOGGLE):
          pi.write(PIN, 1)
          pi.write(PIN, 0)
       e = time.time()
       print("pigpio did {} toggles per second".format(int(TOGGLE/(e-s))))
       pi.stop()
       Timing that shows a speed improvement to roughly 800 toggles per second.
       Now let's use a script.
       pigs proc tag 999 w 22 1 w 22 0 dcr p0 jp 999
       Ignore the details for now.
       Let's time the script running.
       Again, ignore the details for now.
       time (pigs procr 0 10000000; while a=$(pigs procp 0); [[ ${a::1} -eq 2 ]];.br
        do sleep 0.2; done)
       The script takes roughly 12 seconds to complete, or 800,000 toggles per second.
       That is the advantage of a stored script.
       Some details.
       pigs proc tag 999 w 22 1 w 22 0 dcr p0 jp 999
       proc introduces a script.  Everything after proc is part of the script.
       tag 999 names the current position in the script.
       w 22 1 writes 1 to GPIO 22.
       w 22 0 writes 0 to GPIO 22.
       dcr p0 decrements parameter 0.
       jp 999 jumps to tag 999 if the result is positive.
       time (pigs procr 0 10000000; while a=$(pigs procp 0); [[ ${a::1} -eq 2 ]];.br
        do sleep 0.2; done)
       pigs procr 0 10000000 starts script 0 with parameter 0 of 10 million.
       The rest is bash apart from
       pigs  procp  0  asks for the status and parameters of script 0.  The status will be 2 while the script is
       running and 1 when it is complete.
   Virtual machine
       A script runs within a virtual machine with
       a 32 bit accumulator A.
       a flags register F.
       a program counter PC.
       Each script has
       10 parameters named 0 through 9.
       150 variables named 0 through 149.
       50 labels which are named by any unique number.
   Commands
       Many pigpio commands may be used within a script.  However some commands do not work  within  the  script
       model as designed and are not permitted.
       The following commands are not permitted within a script:
       File - FL FO FR FW
       I2C - BI2CZ I2CPK I2CRD I2CRI I2CRK I2CWD I2CWI I2CWK I2CZ
       Misc - BSCX CF1 CF2 SHELL
       Script control - PARSE PROC PROCD PROCP PROCR PROCS PROCU
       Serial - SERO SERR SERW SLR
       SPI - BSPIO BSPIX SPIR SPIW SPIX
       Waves - WVAG WVAS WVCHA WVGO WVGOR
       The following commands are only permitted within a script:
       Command Description                                   Definition
       ADD x   Add x to accumulator                          A+=x; F=A
       AND x   And x with accumulator                        A&=x; F=A
       CALL L  Call subroutine at tag L                      push(PC+1); PC=L
       CMP x   Compare x with accumulator                    F=A-x
       DCR y   Decrement register                            --*y; F=*y
       DCRA    Decrement accumulator                         --A; F=A
       DIV x   Divide x into accumulator                     A/=x; F=A
       EVTWT   Wait for an event to occur                    A=wait(x); F=A
       HALT    Halt                                          Halt
       INR y   Increment register                            ++*y; F=*y
       INRA    Increment accumulator                         ++A; F=A
       JM L    Jump if minus to tag L                        if (F<0) PC=L
       JMP L   Jump to tag L                                 PC=L
       JNZ L   Jump if non-zero to tag L                     if (F) PC=L
       JP L    Jump if positive to tag L                     if (F>=0) PC=L
       JZ L    Jump if zero to tag L                         if (!F) PC=L
       LD y x  Load register with x                          *y=x
       LDA x   Load accumulator with x                       A=x
       MLT x   Multiply x with accumulator                   A*=x; F=A
       MOD x   Modulus x with accumulator                    A%=x; F=A
       OR x    Or x with accumulator                         A|=x; F=A
       POP y   Pop register                                  y=pop()
       POPA    Pop accumulator                               A=pop()
       PUSH y  Push register                                 push(y)
       PUSHA   Push accumulator                              push(A)
       RET     Return from subroutine                        PC=pop()
       RL y x  Rotate left register x bits                   *y<<=x; F=*y
       RLA x   Rotate left accumulator x bits                A<<=x; F=A
       RR y x  Rotate right register x bits                  *y>>=x; F=*y
       RRA x   Rotate right accumulator x bits               A>>=x; F=A
       STA y   Store accumulator in register                 y=A
       SUB x   Subtract x from accumulator                   A-=x; F=A
       SYS str Run external script (/opt/pigpio/cgi/str)     system(str); F=A
       TAG L   Label the current script position             N/A
       WAIT x  Wait for a GPIO in x to change state          A=wait(x); F=A
       X y1 y2 Exchange contents of registers y1 and y2      t=*y1;*y1=*y2;*y2=t
       XA y    Exchange contents of accumulator and register t=A;A=*y;*y=t
       XOR x   Xor x with accumulator                        A^=x; F=A
       x may be a constant, a parameter (p0-p9), or a variable (v0-v149).
       y  may  be  a parameter (p0-p9), or a variable (v0-v149).  If p or v isn't specified y is assumed to be a
       variable.
       The EVTWT command parameter is a bit-mask with 1 set for events of interest.
       The WAIT command parameter is a bit-mask with 1 set for GPIO of interest.
       The SYS script receives two unsigned parameters: the accumulator A and the current GPIO levels.
SEE ALSO
       pigpiod(1), pig2vcd(1), pigpio(3), pigpiod_if(3), pigpiod_if2(3)
AUTHOR
       joan@abyz.me.uk
Linux                                               2012-2020                                            pigs(1)