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Table of Contents
30 [.]XXXXXXXXXXXX[XX][/[ amphours | current | currentbias
| lock.[0-1|ALL] | memory | pages/page.[0-1|ALL] | PIO | sensed | temperature | typeX/range_low
| typeX/range_high | typeX/temperature | vbias | vis | volt | volthours |
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 reading. Units are in Amp (Assumes internal 25 mOhm resistor). Derived from vis / Rinternal.
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 either of the two eprom pages to prevent further writes. Apparently setting lock is permanent.
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.
NOTE that the page property is different from the common OWFS implementation in that all of memory is not accessible.
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.
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 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.
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.
The lower and upper temperature supported by this thermocouple (at least by the conversion routines). In the globally chosen temperature units.
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.
Fixed offset applied to each vis measurement. Used for the volthours value. Units are in Volts.
Range -2.0mV to 2.0mV
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.
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
Integral of vis - vbias over time. Units are in volthours
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.
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.
The 8-bit error correction portion. Uses cyclic redundancy check. Computed from the preceeding 56 bits of the unique ID number. Given as upper case hexidecimal digits (0-9A-F).
The 8-bit family code. Unique to each type of device. Given as upper case hexidecimal digits (0-9A-F).
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.
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.
Is the device currently present on the 1-wire bus?
Note, this means that each hex byte (2 characters) is reversed, not the text string.
Part name assigned by Dallas Semi. E.g. DS2401 Alternative packaging (iButton vs chip) will not be distiguished.
Each device is uniquely unalterably numbered during manufacture. There is a wide variety of devices, including memory, sensors (humidity, temperature, voltage, contact, current), switches, timers, loggers, and more complex devices (like thermocouple sensors) can be built wit hte basic devices. There are also 1-wire devices that have encryption included.
The 1-wire bus is accessed via one of a number of serial, parallel or USB adapters.
There is optional data caching to improved performance, but possible confusion over stale data.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 explanatino of the differences between the DS276x variants, see Dallas Application Note 221.
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.http://pdfserv.maxim-ic.com/en/ds/DS2760.pdf
http://pdfserv.maxim-ic.com/en/an/app221.pdf owfs (1) owhttpd (1) owftpd (1) owserver (1) owtcl (3) owperl (3) DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3) DS2401 (3) DS1990A (3) DS1982 (3) DS1985 (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995 (3) DS1996 (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS2804 (3) DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS1822 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3) DS1922 (3) DS2450 (3) DS2890 (3) DS2436 (3) DS2438 (3) DS2760 (3) DS2423 (3) LCD (3) DS2408 (3) DS1977 (3) http://owfs.sourceforge.net