DS2437(3) One-Wire File System DS2437(3)NAMEDS2437 - Smart Battery Monitor
SYNOPSIS
Temperature Voltages and Memory.
1E [.]XXXXXXXXXXXX[XX][/[ current | date | disconnect/date | discon‐
nect/udate | endcharge/date | endcharge/udate | Ienable |
pages/page.[0-7|ALL] | temperature | udate | VAD | VDD | ]]
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 per‐
formed 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) or owhttpd(1) 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 PROPERTIESALARMS
None.
DESCRIPTIONDS2437
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 cor‐
recting circuit nmeasurements to supply voltage and temperature. A bet‐
ter comparison is the DS276x family of chips.
ADDRESSINGDATASHEET
http://pdfserv.maxim-ic.com/en/ds/DS2437.pdf
http://pdfserv.maxim-ic.com/en/an/humsensor.pdf
SEE ALSOAVAILABILITY
http://www.owfs.org
AUTHOR
Paul Alfille (paul.alfille@gmail.com)
OWFS Manpage 2003 DS2437(3)
