--- name: "DS2437" section: "3" platform: "linux" package: "owfs-doc" version: "3.2p4+dfsg1-6" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/DS2437" --- # DS2437(3) Smart Battery Monitor ## NAME **DS2437** - Smart Battery Monitor ## SYNOPSIS Temperature Voltages and Memory. **1E** \[.\]XXXXXXXXXXXX\[XX\]\[/\[ **current** \| **date** \| **disconnect/date** \| **disconnect/udate** \| **endcharge/date** \| **endcharge/udate** \| *Ienable* \| **pages/page.\[0-7\|ALL\]** \| **temperature** \| **udate** \| **VAD** \| **VDD** \| **address** \| **crc8** \| **id** \| **locator** \| **r\_address** \| **r\_id** \| **r\_locator** \| **type** \]\] ## FAMILY CODE *1E* ## SPECIAL PROPERTIES ### date *read-write, ascii*\ 26 character date representation of the *counter* value. Increments once per second.\ Setting *date* to a null string will put the current system time.\ Accepted date formats are:\ \ Sat\[urday\] March 12 12:23:59 2001\ \ Apr\[il\] 4 9:34:56 2002\ \ 3/23/04 23:34:57\ \ current locale setting (your system's format) ### current *read-only, integer*\ Current reading. Actual current depends on Rsens resistor (see datasheet).\ The formula for current is I = *current* /(4096\*Rsens)\ with units in Amps and Ohms.\ Current measurement will be temporarily enabled (see *Ienable* ) if not currently enabled (pun intended) for this reading. ### disconnect/date *read-write, ascii*\ 26 character date representation of the *disconnect/udate* value. Time when the battery pack waws removed from the charger. Format is the same as the *date* property. ### disconnect/udate *read-write, unsigned integer*\ Representation of *disconnect/date* as a number. See *udate* for details. ### endcharge/date *read-write, ascii*\ 26 character date representation of the *endcharge/udate* value. Format is the same as the *date* property. ### endcharge/udate *read-write, unsigned integer*\ Representation of *endcharge/date* as a number. See *udate* for details. ### Ienable *read-write, unsigned integer*\ Status of *current* monitoring. When enabled, current sensing is performed 36.41 times/second. Values of *Ienable* are: - **0** no current conversion - **1** current conversion enabled - **2** current conversion and accumulation - **3** current conversion and accumulation with EEPROM backup ### pages/page.0 ... pages/page.7 pages/page.ALL *read-write, binary*\ Memory is split into 8 pages of 8 bytes each. Only the pages 3-7 are really available, and some of that appears to be reserved. See the datasheet for details.\ *ALL* is an aggregate of the pages. Each page is accessed sequentially. ### 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)](/owfs/1.md)** or **[owhttpd(1)](/owhttpd/1.md)** for choices. Default is Celsius. Conversion takes ~20 msec. ### udate *read-write, unsigned integer*\ Time represented as a number. *udate* increments once per second.\ Usually set to unix time standard: number of seconds since Jan 1, 1970. The *date* field will be the unix representation (ascii text) of *udate* and setting either will change the other. ### VAD VDD *read-only, floating point*\ Voltage read (~10 bits) at the one of the chip's two supply voltages. Range VDD= 2.4V to 10V, VAD=1.5 to 10V. ## 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 fundamental goal has been ease of use, flexibility and correctness rather than speed. ### DS2437 The **DS2437 (3)** is an obsolete version of the **DS2438 (3)** battery chip. Current sensing is available, but not implemented. The major advantage compared to the **DS2436** is that two voltages can be read, allowing correcting circuit nmeasurements to supply voltage and temperature. A better comparison is the **DS276x** family of chips. ## 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/DS2437.pdf\ http://pdfserv.maxim-ic.com/en/an/humsensor.pdf ## 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) InfernoEmbedded (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) MAX31826 (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 (3) EDS0066 (3) EDS0068 (3)** ### Moisture **EEEF (3) DS2438 (3)** ## AVAILABILITY http://www.owfs.org ## AUTHOR Paul Alfille (paul.alfille@gmail.com)