Ubuntu Manpage: DS2760, DS2761, DS2762 - High-Precision Li+ Battery Monitor

NAME

       DS2760, DS2761, DS2762 - High-Precision Li+ Battery Monitor

SYNOPSIS

   Temperature Voltage and Current.
       30  [.]XXXXXXXXXXXX[XX][/[  amphours  |  current | currentbias | lock.[0-1|ALL] | memory |
       pages/page.[0-1|ALL] | PIO | sensed | temperature | vbias | vis | volt | volthours |
       cc | ce | coc | defaultpmod | defaultswen | dc | de | doc | mstr | ov | ps | pmod | swen |
       uv |
       address | crc8 | id | locator | r_address | r_id | r_locator | type ]]

   Thermocouple
       30   [.]XXXXXXXXXXXX[XX][/[   temperature   |   typeX/range_low   |   typeX/range_high   |
       typeX/temperature ]]

   Weather Station
       30  [.]XXXXXXXXXXXX[XX][/[  WS603/temperature  |  WS603/wind_speed  |  WS603/direction   |
       WS603/volt |
       WS603/LED/status | WS603/LED/control.ALL | WS603/LED/model |
       WS603/calibrationwind_speed | WS603/calibration/direction |
       WS603/light/intensity | WS603/light/threshold

FAMILY CODE

SPECIAL PROPERTIES

amphours
read-write, floating point
Accumulated amperage read by current sensor. Units are in Amp-hr (Assumes internal 25mOhm
resistor). Derived from volthours / Rinternal.
Formally amphours is the integral of current - currentbias over time.

current
read-only, floating point
Current reading. Units are in Amp (Assumes internal 25 mOhm resistor). Derived from vis /
Rinternal.

currentbias
read-write, floating point
Fixed offset applied to each current measurement. Used in the amphours value. Assumes
internal 25mOhm resistor. Units are Amp and range from -.08A to .08A.
Derived from vbias / Rinternal.

lock.[0-1|ALL]
read-write, yes-no
Lock either of the two eprom pages to prevent further writes. Apparently setting lock is
permanent.

memory
read-write, binary
Access to the full 256 byte memory range. Much of this space is reserved or special use.
User space is the page area.
See the DATASHEET for a full memory map.

pages/pages.[0-1|ALL]
read-write, binary Two 16 byte areas of memory for user application. The lock property can
prevent further alteration.
NOTE that the page property is different from the common OWFS implementation in that all
of memory is not accessible.

PIO
write-only, yes-no
Controls the PIO pin allowing external switching.
Writing "1" turns the PIO pin on (conducting). Writing "0" makes the pin non-conducting.
The logical state of the voltage can be read with the sensed property. This will reflect
the current voltage at the pin, not the value sent to PIO
Note also that PIO will also be altered by the power-status of the DS2670 See the
datasheet for details.

sensed
read-only, yes-no
The logical voltage at the PIO pin. Useful only if the PIO property is set to "0" (non-
conducting).
Value will be 0 or 1 depending on the voltage threshold.

temperature
read-only, floating point
Temperature read by the chip at high resolution (~13 bits). Units are selected from the
invoking command line. See owfs(1) or owhttpd(1) for choices. Default is Celsius.
Conversion is continuous.

vbias
read-write, floating point
Fixed offset applied to each vis measurement. Used for the volthours value. Units are in
Volts.
Range -2.0mV to 2.0mV

vis
read-only, floating point
Current sensor reading (unknown external resistor). Measures the voltage gradient between
the Vis pins. Units are in Volts
The vis readings are integrated over time to provide the volthours property.
The current reading is derived from vis assuming the internal 25 mOhm resistor is
employed. There is no way to know this through software.

volt
read-only, floating point
Voltage read at the voltage sensor;. This is separate from the vis voltage that is used
for current measurement. Units are Volts
Range is between 0 and 4.75V

volthours
read-write, floating point
Integral of vis - vbias over time. Units are in volthours

THERMOCOUPLE

   typeX/
       directory
       Thermocouple  circuit  using  the  DS2760  to  read  the Seebeck voltage and the reference
       temperature. Since the type interpretation of the values  read  depends  on  the  type  of
       thermocouple,  the  correct directory must be chosen. Supported thermocouple types include
       types B, E, J, K, N, R, S and T.

   typeX/range_low typeX/ranges_high
       read-only, flaoting point
       The lower and upper temperature supported by this thermocouple (at least by the conversion
       routines). In the globally chosen temperature units.

   typeX/temperature
       read-only, floating point
       Thermocouple  temperature.  Requires  a  voltage  and  temperature conversion. Returned in
       globally chosen temperature units.
       Note: there are two types of temperature measurements possible. The temperature  value  in
       the   main   device  directory  is  the  reference  temperature  read  at  the  chip.  The
       typeX/temperature value is at the thermocouple junction, probably remote from the chip.

WEATHER STATION

WS603
directory
Weather station from AAG electronica that includes temperature, wind speed, wind
direction, light sensor and LED lights.

WS603/temperature
read-only, floating-point
Uses the DS2760 temperature sensor. This is equivalent to the temperature value. Again in
the specificed temperature scale, default Celsius.

WS603/wind_speed
read_only, floating-point
Readings from the anometer, scaled using the WS603/calibration/wind_speed

WS603/direction
read_only, unsigned integer
Wind direction, using the following table

1 N

2 NNE

3 NE

4 NEE

5 E

6 EES

7 ES

8 ESS

9 S

10 SSW

11 SW

12 SWW

13 W

14 WWN

15 WN

16 WWN

Values are adjusted (internally) by the WS603/calibration/direction property

WS603/volt
read-only, unsigned integer
Voltage value from the WS603 device. Units and significance is unclear.

WS603/calibration/wind_speed
read-write, unsigned integer
Value between 1 and 200 for wind speed scaling. Values on of this range are ignored and
the default value of 100 used.

WS603/calibration/direction
read-write, unsigned integer
Adjustment of wind direction. See datasheet.

WS603/light/intensity
read-only, unsigned integer
Uncalibrated value from an internal light sensor. Used for control of LED display (daytime
vs nighttime).

WS603/light/threshold
read-only, unsigned integer
Threshold for internal light sensor. Used for control of LED display (daytime vs
nighttime).

Value is set as value 4 of the array passed to WS603/LED/control

WS603/LED/status
read-only, unsigned integer
Status of LED lights intensities. See datasheet.

Value is set as values 2 and 3 of the array passed to WS603/LED/control

WS603/LED/model
read-only, unsigned integer
What factors control LED display. See datasheet.

Value is set as value 1 of the array passed to WS603/LED/control.ALL

WS603/LED/model
write-only, unsigned integer array of 4 values
Four integers sent to control LED display. All four values must be sent, comma separated.

0 Light mode

1 Light status

2 Light level

3 Light threshold

OBSCURE PROPERTIES

   cc ce coc dc de doc mstr ov pmod swen uv
       varies, yes-no
       Bit  flags  corresponding  to  various  battery  management functions of the chip. See the
       DATASHEET for details of the identically named entries.
       In general, writing "0" corresponds to a 0 bit value, and non-zero corresponds to a 1  bit
       value.

   defaultpmod defaultswen
       read-write, yes-no
       Default power-on state for the corresponding properties.

STANDARD PROPERTIES

address
r_address
read-only, ascii
The entire 64-bit unique ID. Given as upper case hexadecimal 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 hexadecimal digits (0-9A-
F).

family
read-only, ascii
The 8-bit family code. Unique to each type of device. Given as upper case hexadecimal
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 hexadecimal 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 hexadecimal) 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

       None.

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 principle 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.

DS2760 DS2761 DS2762
The DS2760 (3) is a class of battery charging controllers. There are minor hardware
difference between the DS2760, DS2761 and DS2762 battery chip, but they are
indistiguishable to the software.

A number of interesting devices can be built with the DS276x including thermocouples.
Support for thermocouples in built into the software, using the embedded thermister as the
cold junction temperature.

For an explanation of the differences between the DS276x variants, see Dallas Application
Note 221.

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 hexadecimal, 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/DS2760.pdf
       http://pdfserv.maxim-ic.com/en/an/app221.pdf
       http://www.aag.com.mx/aagusa/contents/en-
       us/Description%20of%20WSV3%20Interface%20(1-wire).pdf

AVAILABILITY

       http://www.owfs.org

AUTHOR

       Paul Alfille (paul.alfille@gmail.com)