The driver was developed using the Veris CWLSHTA CO2 Gas sensor. The
'T' variant supports a temperature sensor, and the 'H' variant
supports a humidity sensor.
All 3 signals are provided by the device as analog 0-5Vdc, 0-10Vdc, or
4-20ma loop current outputs. For devices supporting temperature, the
valid temperature range is 10C to 50C. The humidity ranges from 0% to
100% (non-condensing). The CO2 sensor ranges from 0 to 2000 ppm.
This driver was developed using the 5Vdc outputs and the 4-20ma
outputs. For voltage outputs, your MCU must be configured for 5V
operation. In addition, you must configure the sensor (via it's
configuration switches) to output 0-5VDC only. Using any other analog
reference voltage will require the appropriate external circuitry
(such as a voltage divider) in order to interface safely with your
MCU.
In addition, the sensor can be configured for 4-20ma usage, by
specifying the correct receiver resistance (in ohms) in the
constructor. This sensor was tested with a Cooking Hacks (Libelium)
4-channel 4-20ma Arduino interface shield. For this interface, the
receiver resistance was specified as 165.0 ohms.
Signed-off-by: Jon Trulson <jtrulson@ics.com>
Signed-off-by: Abhishek Malik <abhishek.malik@intel.com>
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