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DS2450(3)                    One-Wire File System                    DS2450(3)


DS2450 - Quad A/D Converter


Voltage * 4 and Memory. 20 [.]XXXXXXXXXXXX[XX][/[ PIO.[A-D|ALL] | volt.[A-D|ALL] | volt2.[A-D|ALL] ]] 20 [.]XXXXXXXXXXXX[XX][/[ 8bit/volt.[A-D|ALL] | 8bit/volt2.[A-D|ALL] ]] 20 [.]XXXXXXXXXXXX[XX][/[ memory | pages/page.[0-3|ALL] | power ] 20 [.]XXXXXXXXXXXX[XX][/[ alarm/high.[A-D|ALL] | alarm/low.[A-D|ALL] | set_alarm/high.[A-D|ALL] | set_alarm/low.[A-D|ALL] | set_alarm/unset | set_alarm/volthigh.[A-D|ALL] | set_alarm/volt2high.[A-D|ALL] | set_alarm/voltlow.[A-D|ALL] | set_alarm/volt2low.[A-D|ALL] ] 20 [.]XXXXXXXXXXXX[XX][/[ See the file man3/standard_mini.3so. ]] CO2 sensor 20 [.]XXXXXXXXXXXX[XX][/[ CO2/ppm | CO2/power | CO2/status ]




alarm/high.A ... alarm/high.D alarm.high.ALL alarm/high.A ... alarm/high.D alarm.high.ALL read-write, binary The alarm state of the voltage channel. The alarm state is set one of two ways: voltage conversion Whenever the DS2450 measures a voltage on a channel, that voltage is compared to the high and low limits set_alarm/volthigh and/or set_alarm/voltlow and if the alarm is enabled set_alarm/high and/or set_alarm/low the corresponding flag is set in alarm/high and/or alarm/low manual set The flag can be set by a direct write to alarm/high or alarm/low memory read-write, binary 32 bytes of data. Much has special implications. See the datasheet. pages/page.0 ... pages/page.3 pages/page.ALL read-write, binary Memory is split into 4 pages of 8 bytes each. Mostly for reading and setting device properties. See the datasheet for details. ALL is an aggregate of the pages. Each page is accessed sequentially. PIO.A ... PIO.D PIO.ALL read-write, yes-no Pins used for digital control. 1 turns the switch on (conducting). 0 turns the switch off (non-conducting). Control is specifically enabled. Reading volt will turn off this control. ALL is an aggregate of the voltages. Readings are made separately. power read-write, yes-no Is the DS2450 externally powered? (As opposed to parasitically powered from the data line). The analog A/D will be kept on continuously. And the bus will be released during a conversion allowing other devices to communicate. Set true (1) only if Vcc powered (not parasitically powered). Unfortunately, the DS2450 cannot sense it's powered state. This flag must be explicitly written, and thus is a potential source of error if incorrectly set. It is always safe to leave power set to the default 0 (off) state. set_alarm/high.A ... set_alarm/high.D set_alarm/high.ALL set_alarm/low.A ... set_alarm/low.D set_alarm/low.ALL read-write, yes-no Enabled status of the voltage threshold. 1 is on. 0 is off. set_alarm/volthigh.A ... set_alarm/volthigh.D set_alarm/volthigh.ALL set_alarm/volt2high.A ... set_alarm/volt2high.D set_alarm/volt2high.ALL set_alarm/voltlow.A ... set_alarm/voltlow.D set_alarm/voltlow.ALL set_alarm/volt2low.A ... set_alarm/volt2low.D set_alarm/volt2low.ALL read-write, floating point The upper or lower limit for the voltage measured before triggering an alarm. Note that the alarm must be enabled alarm/high or alarm.low and an actual reading must be requested volt for the alarm state to actually be set. The alarm state can be sensed at alarm/high and alarm/low set_alarm/unset read-write, yes-no Status of the power-on-reset (POR) flag. The POR is set when the DS2450 is first powered up, and will match the alarm state until explicitly cleared. (By writing 0 to it). The purpose of the POR is to alert the user that the chip is not yet fully configured, especially alarm thresholds and enabling. volt.A ... volt.D volt.ALL 8bit/volt.A ... 8bit/volt.D 8bit/volt.ALL read-only, floating point Voltage read, 16 bit resolution (or 8 bit for the 8bit directory). Range 0 - 5.10V. Output ( PIO ) is specifically disabled. ALL is an aggregate of the voltages. Readings are made separately. volt2.A ... volt2.D volt2.ALL 8bit/volt2.A ... 8bit/volt2.D 8bit/volt2.ALL read-only, floating point Voltage read, 16 bit resolution (or 8 bit for the 8bit directory). Range 0 - 2.55V. Output ( PIO ) is specifically disabled. ALL is an aggregate of the voltages. Readings are made separately. CO2 (Carbon Dioxide) SENSOR PROPERTIES The CO2 sensor is a device constructed from a SenseAir K30 and a DS2450 CO2/power read-only, floating point Supply voltage to the CO2 sensor (should be around 5V) CO2/ppm read-only, unsigned CO2 level in ppm (parts per million). Range 0-5000. CO2/status read-only, yes-no Is the internal voltage correct (around 3.2V)?


See the file man3/standard.3so.




See the file man3/description.3so. DS2450 The DS2450 (3) is a (supposedly) high resolution A/D converter with 4 channels. Actual resolutin is reporterd to be 8 bits. The channels can also function as switches. Voltage sensing (with temperature and current, but sometimes restricted voltrage ranges) can also be obtained with the DS2436 , DS2438 and DS276x


See the file man3/addressing.3so.


DS2450 http://pdfserv.maxim-ic.com/en/ds/DS2450.pdf CO2 sensor http://www.senseair.se/Datablad/k30%20.pdf CO2 device https://www.m.nu/co2meter-version-2-p-259.html?language=en


See the file man3/seealso.3so.




Paul Alfille (paul.alfille@gmail.com) OWFS Manpage 2003 DS2450(3)

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