Provided by: owfs-doc_2.8p13+dfsg1-5build1_all bug

NAME

       DS2408 - 1-Wire 8 Channel Addressable Switch

SYNOPSIS

       8 port switch

       29   [.]XXXXXXXXXXXX[XX][/[  latch.[0-7|ALL|BYTE]  |  LCD_M/[clear|home|screen|message]  |
       LCD_H/[clear|home|yxscreen|screen|message|onoff]   |   PIO.[0-7|ALL|BYTE]   |   power    |
       sensed.[0-7|ALL|BYTE]  |  strobe  |  por  |  set_alarm  |  address | crc8 | id | locator |
       r_address | r_id | r_locator | type ]]

FAMILY CODE

       29

SPECIAL PROPERTIES

   latch.0 ... latch.7 latch.ALL latch.BYTE
       read-write, binary
       The 8 pins (PIO) latch a bit when their state changes, either  externally,  or  through  a
       write to the pin.
       Reading the latch property indicates that the latch has been set.
       Writing "true" (non-zero) to ANY latch will reset them all. (This is the hardware design).
       ALL is all latch states, accessed simultaneously, comma separated.
       BYTE references all channels simultaneously as a single byte. Channel 0 is bit 0.

   PIO.0 ... PIO.7 PIO.ALL PIO.BYTE
       read-write, yes-no
       State of the open-drain output ( PIO ) pin. 0 = non-conducting (off), 1 = conducting (on).
       Writing  zero  will turn off the switch, non-zero will turn on the switch. Reading the PIO
       state will return the switch setting. To determine the actual logic level at  the  switch,
       refer to the sensed.0 ... sensed.7 sensed.ALL sensed.BYTE property.
       ALL references all channels simultaneously, comma separated.
       BYTE references all channels simultaneously as a single byte. Channel 0 is bit 0.

   power
       read-only, yes-no
       Is the DS2408 powered parasitically (0) or separately on the Vcc pin (1)?

   sensed.0 ... sensed.7 sensed.ALL
       read-only, yes-no
       Logic level at the PIO pin. 0 = ground. 1 = high (~2.4V - 5V ). Really makes sense only if
       the PIO state is set to zero (off), else will read zero.
       ALL references all channels simultaneously, comma separated.
       BYTE references all channels simultaneously as a single byte. Channel 0 is bit 0.

   strobe
       read-write, yes-no
       RSTZ Pin Mode Control. Configures RSTZ as either RST input or STRB output:

       0      configured as RST input (default)

       1      configured as STRB output

   por
       read-write, yes-no
       Specifies whether the device has performed power-on reset. This bit can only be cleared to
       0  under  software  control. As long as this bit is 1 the device will allways respond to a
       conditional search.

   set_alarm
       read-write, integer unsigned (0-333333333)
       A number consisting of 9 digits XYYYYYYYY, where:

       X      select source and logical term
              0 PIO   OR
              1 latch OR
              2 PIO   AND
              3 latch AND

       Y      select channel and polarity
              0 Unselected (LOW)
              1 Unselected (HIGH)
              2 Selected    LOW
              3 Selected    HIGH

       All digits will be truncated to the 0-3 range.  Leading  zeroes  are  optional.  Low-order
       digit is channel 0.

       Example:

       100000033
              Responds on Conditional Search when latch.1 or latch.0 are set to 1.

       222000000
              Responds on Conditional Search when sensed.7 and sensed.6 are set to 0.

       000000000 (0)
              Never responds to Conditional Search.

LCD_H LCD SCREEN PROPERITES

       This  mode uses the DS2408 attached to a Hitachi HD44780 LCD controller in 4-bit mode. See
       DATASHEET for published details. Based on a commercial product from  HobbyBoards  by  Erik
       Vickery.

   LCD_H/clear
       write-only, yes-no
       This will clear the screen and place the cursor at the start.

   LCD_H/home
       write-only, yes-no
       Positions  the  cursor  in  the  home  (upper  left) position, but leaves the current text
       intact.

   LCD_H/screen
       write-only, ascii text
       Writes to the LCD screen at the current position.

   LCD_H/screenyc
       write-only, ascii text
       Writes to an LCD screen at a specified location. The controller doesn't know the true  LCD
       dimensions, but typical selections are: 2x16 2x20 4x16 and 4x20.

       Y (row)
              range 1 to 2 (or 4)

       X (column)
              range 1 to 16 (or 20)

       There  are  two  formats  allowed for the screenyx text, either ascii (readable text) or a
       binary form.

       2 binary bytes
              The two first characters  of  the  passed  string  have  the  line  and  row:  e.g.
              "\x02\x04string" perl string writes "string" at line 2 column 4.

       ascii 2,12:
              Two  numbers  giving line and row:  Separate with a comma and end with a colon e.g.
              "2,4:string" writes "string" at line 2 column 4.

       ascii 12:
              Single column  number  on  the  (default)  first  line:   End  with  a  colon  e.g.
              "12:string" writes "string" at line 1 column 12.

       The positions are 1-based (i.e. the first position is 1,1).

   LCD_H/onoff
       write-only, unsigned
       Sets several screen display functions. The selected choices should be added together.

       4      Display on

       2      Cursor on

       1      Cursor blinking

   LCD_H/message
       write-only, ascii text
       Writes  a  message to the LCD screen after clearing the screen first.  This is the easiest
       way to display a message.

LCD_M LCD SCREEN PROPERITES

       This mode uses the DS2408 attached to a Hitachi HD44780 LCD controller in 8-bit mode.  See
       DATASHEET  for  published  details.  Based on a design from Maxim and a commercial product
       from AAG.

   LCD_M/clear
       write-only, yes-no
       This will clear the screen and place the cursor at the start.

   LCD_M/home
       write-only, yes-no
       Positions the cursor in the home (upper  left)  position,  but  leaves  the  current  text
       intact.

   LCD_M/screen
       write-only, ascii text
       Writes to the LCD screen at the current position.

   LCD_M/screenyc
       write-only, ascii text
       Writes  to an LCD screen at a specified location. The controller doesn't know the true LCD
       dimensions, but typical selections are: 2x16 2x20 4x16 and 4x20.

       Y (row)
              range 1 to 2 (or 4)

       X (column)
              range 1 to 16 (or 20)

       There are two formats allowed for the screenyx text, either ascii  (readable  text)  or  a
       binary form.

       2 binary bytes
              The  two  first  characters  of  the  passed  string  have  the  line and row: e.g.
              "\x02\x04string" perl string writes "string" at line 2 column 4.

       ascii 2,12:
              Two numbers giving line and row:  Separate with a comma and end with a  colon  e.g.
              "2,4:string" writes "string" at line 2 column 4.

       ascii 12:
              Single  column  number  on  the  (default)  first  line:   End  with  a  colon e.g.
              "12:string" writes "string" at line 1 column 12.

       The positions are 1-based (i.e. the first position is 1,1).

   LCD_M/onoff
       write-only, unsigned
       Sets several screen display functions. The selected choices should be added together.

       4      Display on

       2      Cursor on

       1      Cursor blinking

   LCD_M/message
       write-only, ascii text
       Writes a message to the LCD screen after clearing the screen first.  This is  the  easiest
       way to display a message.

STANDARD PROPERTIES

   address
   r_address
       read-only, ascii
       The entire 64-bit unique ID. Given as upper case hexidecimal digits (0-9A-F).
       address starts with the family code
       r  address  is the address in reverse order, which is often used in other applications and
       labeling.

   crc8
       read-only, ascii
       The 8-bit error correction portion.  Uses  cyclic  redundancy  check.  Computed  from  the
       preceding  56  bits of the unique ID number. Given as upper case hexidecimal digits (0-9A-
       F).

   family
       read-only, ascii
       The 8-bit family code. Unique to each type of device.  Given  as  upper  case  hexidecimal
       digits (0-9A-F).

   id
   r_id
       read-only, ascii
       The  48-bit  middle  portion  of the unique ID number. Does not include the family code or
       CRC. Given as upper case hexidecimal digits (0-9A-F).
       r id is the id in reverse order, which is often used in other applications and labeling.

   locator
   r_locator
       read-only, ascii
       Uses an extension of the 1-wire design from iButtonLink  company  that  associated  1-wire
       physical connections with a unique 1-wire code. If the connection is behind a Link Locator
       the locator will show a unique 8-byte number  (16  character  hexidecimal)  starting  with
       family code FE.
       If no Link Locator is between the device and the master, the locator field will be all FF.
       r locator is the locator in reverse order.

   present (DEPRECATED)
       read-only, yes-no
       Is the device currently present on the 1-wire bus?

   type
       read-only, ascii
       Part  name  assigned  by Dallas Semi. E.g.  DS2401 Alternative packaging (iButton vs chip)
       will not be distiguished.

ALARMS

       Use the set_alarm property to set the alarm triggering criteria.

DESCRIPTION

   1-Wire
       1-wire is a wiring protocol and series of devices  designed  and  manufactured  by  Dallas
       Semiconductor,  Inc.  The bus is a low-power low-speed low-connector scheme where the data
       line can also provide power.

       Each device is uniquely and unalterably numbered during  manufacture.  There  are  a  wide
       variety  of  devices,  including memory, sensors (humidity, temperature, voltage, contact,
       current), switches, timers and data  loggers.  More  complex  devices  (like  thermocouple
       sensors)  can  be  built with these basic devices. There are also 1-wire devices that have
       encryption included.

       The 1-wire scheme uses a single bus master and multiple slaves on the same wire.  The  bus
       master  initiates  all  communication.  The  slaves  can  be  individually  discovered and
       addressed using their unique ID.

       Bus masters come in a variety of configurations including serial, parallel,  i2c,  network
       or USB adapters.

   OWFS design
       OWFS  is  a  suite of programs that designed to make the 1-wire bus and its devices easily
       accessible. The underlying priciple is to create a virtual filesystem, with the unique  ID
       being the directory, and the individual properties of the device are represented as simple
       files that can be read and written.

       Details of the individual slave or master design are hidden behind a consistent interface.
       The  goal  is to provide an easy set of tools for a software designer to create monitoring
       or control applications. There are some performance enhancements  in  the  implementation,
       including  data  caching,  parallel  access  to  bus  masters,  and  aggregation of device
       communication.  Still  the  fundemental  goal  has  been  ease  of  use,  flexibility  and
       correctness rather than speed.

   DS2408
       The  DS2408  (3)  allows  control  of  other devices, like LEDs and relays. It extends the
       DS2406 to 8 channels and includes memory.
       Alternative switches include the DS2406, DS2407 and even DS2450

ADDRESSING

       All 1-wire devices are factory assigned a unique 64-bit address. This address  is  of  the
       form:

       Family Code
              8 bits

       Address
              48 bits

       CRC    8 bits

       Addressing under OWFS is in hexidecimal, of form:

              01.123456789ABC

       where 01 is an example 8-bit family code, and 12345678ABC is an example 48 bit address.

       The dot is optional, and the CRC code can included. If included, it must be correct.

DATASHEET

       http://pdfserv.maxim-ic.com/en/ds/DS2408.pdf
       http://www.hobby-boards.com/catalog/howto_lcd_driver.php
       http://www.maxim-ic.com/appnotes.cfm/appnote_number/3286

SEE ALSO

   Programs
       owfs  (1)  owhttpd  (1) owftpd (1) owserver (1) owdir (1) owread (1) owwrite (1) owpresent
       (1) owtap (1)

   Configuration and testing
       owfs (5) owtap (1) owmon (1)

   Language bindings
       owtcl (3) owperl (3) owcapi (3)

   Clocks
       DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)

   ID
       DS2401 (3) DS2411 (3) DS1990A (3)

   Memory
       DS1982 (3) DS1985 (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995  (3)  DS1996  (3)
       DS2430A (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS28E04 (3) DS28EC20 (3)

   Switches
       DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)

   Temperature
       DS1822  (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3)
       DS28EA00 (3) DS28E04 (3) EDS0064 (3) EDS0065 (3)  EDS0066  (3)  EDS0067  (3)  EDS0068  (3)
       EDS0071 (3) EDS0072 (3)

   Humidity
       DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (3)

   Voltage
       DS2450 (3)

   Resistance
       DS2890 (3)

   Multifunction (current, voltage, temperature)
       DS2436  (3)  DS2437  (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3)
       DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)

   Counter
       DS2423 (3)

   LCD Screen
       LCD (3) DS2408 (3)

   Crypto
       DS1977 (3)

   Pressure
       DS2406 (3) -- TAI8570 EDS0066 (3) EDS0068 (3)

AVAILABILITY

       http://www.owfs.org

AUTHOR

       Paul Alfille (paul.alfille@gmail.com)