DS2740 - High-Precision Coulomb Counter

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

       FamilyCode
              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.

       None.

       Paul Alfille (paul.alfille@gmail.com)

OWFS Manpage                                          2003                                             DS2740(3)

http://www.owfs.org

http://pdfserv.maxim-ic.com/en/ds/DS2740.pdf

1-Wire1-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 busmaster 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.

   OWFSdesignOWFS  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 fundamental goal has been ease of use,
       flexibility and correctness rather than speed.

   DS2740
       The DS2740(3) is a class of battery charging controllers. This chip measures voltage and volthours,  and
       has a pin that can be used for control.

36

DS2740 - High-Precision Coulomb Counter

smodread-write,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.
       Default power-on state for the corresponding properties.

Programsowfs(1)owhttpd(1)owftpd(1)owserver(1)owdir(1)owread(1)owwrite(1)owpresent(1)owtap(1)Configurationandtestingowfs(5)owtap(1)owmon(1)Languagebindingsowtcl(3)owperl(3)owcapi(3)ClocksDS1427(3)DS1904(3)DS1994(3)DS2404(3)DS2404S(3)DS2415(3)DS2417(3)IDDS2401(3)DS2411(3)DS1990A(3)MemoryDS1982(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)SwitchesDS2405(3)DS2406(3)DS2408(3)DS2409(3)DS2413(3)DS28EA00(3)InfernoEmbedded(3)TemperatureDS1822(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)MAX31826(3)HumidityDS1922(3)DS2438(3)EDS0065(3)EDS0068(3)VoltageDS2450(3)ResistanceDS2890(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)CounterDS2423(3)LCDScreenLCD(3)DS2408(3)CryptoDS1977(3)PressureDS2406(3)TAI8570(3)EDS0066(3)EDS0068(3)MoistureEEEF(3)DS2438(3)

memoryread-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.

   PIOwrite-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.

   sensedread-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.

   visread-only,floatingpoint
       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.

   vis_Bread-only,floatingpoint
       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  vis_B  is  from a different tuning of the DS2740(3) chip with faster sampling and lower resolution.
       There is no way to know this through software.

   volthoursread-write,floatingpoint
       Integral of vis over time. Units are in volthours

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

   crc8read-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).

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

   idr_idread-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).
       rid is the id in reverse order, which is often used in other applications and labeling.

   locatorr_locatorread-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 LinkLocator the locatorwillshowaunique8-bytenumber(16characterhexadecimal)startingwithfamilycodeFE.
       If no LinkLocator is between the device and the master, the locator field will be all FF.
       rlocator is the locator in reverse order.

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

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

       Voltage and Switch

       36 [.]XXXXXXXXXXXX[XX][/[ memory | PIO | sensed | vis | vis_B | volthours |
       smod |
       address | crc8 | id | locator | r_address | r_id | r_locator | type ]]