Hey BSTRobin,
apologies for the delayed response. In the original firmware we did not log gas resistance at all. I have been experiementing both in Arduino and esp-idf and have found the BSEC_OUTPUT_RAW_GAS measurement to be static.
I have also tried running the stock arduino bsec library example https://github.com/BoschSensortec/BSEC-Arduino-library/blob/master/examples/basic/basic.ino and got the same results on our custom hardware and on a adafruit bme680 dev board found at https://www.mouser.co.uk/new/adafruit/adafruit-bme680-dev-board/
The following is a sample arduino example output
Time ,raw Temp, Press,raw Hum, Gas resistance, IAQ, acc, temp, humidity, static iaq, co2equiv, breathVocEquivalent
1737036, 23.75, 101385.00, 36.38, 12887828.00, 85.26, 1, 23.69, 36.52, 51.32, 605.30, 0.74
1740036, 23.75, 101379.00, 36.36, 12887828.00, 85.71, 1, 23.69, 36.50, 51.52, 606.09, 0.75
1743036, 23.75, 101379.00, 36.35, 12887828.00, 86.16, 1, 23.69, 36.49, 51.72, 606.87, 0.75
1746036, 23.75, 101379.00, 36.34, 12887828.00, 86.60, 1, 23.69, 36.48, 51.91, 607.64, 0.75
1749036, 23.74, 101379.00, 36.34, 12887828.00, 87.04, 1, 23.68, 36.50, 52.10, 608.41, 0.75
1752037, 23.74, 101383.00, 36.34, 12887828.00, 87.46, 1, 23.68, 36.50, 52.28, 609.13, 0.76
1755037, 23.75, 101381.00, 36.34, 12887828.00, 87.84, 1, 23.69, 36.47, 52.45, 609.79, 0.76
1758036, 23.74, 101383.00, 36.36, 12887828.00, 88.20, 1, 23.68, 36.51, 52.61, 610.43, 0.76
1761036, 23.74, 101383.00, 36.36, 12887828.00, 88.54, 1, 23.68, 36.51, 52.76, 611.03, 0.76
1764037, 23.74, 101381.00, 36.36, 12887828.00, 88.87, 1, 23.68, 36.51, 52.90, 611.60, 0.76
1767037, 23.74, 101381.00, 36.37, 12887828.00, 89.17, 1, 23.68, 36.52, 53.03, 612.13, 0.76
1770037, 23.74, 101381.00, 36.38, 12887828.00, 89.45, 1, 23.68, 36.52, 53.15, 612.62, 0.77
1773037, 23.74, 101381.00, 36.40, 12887828.00, 89.70, 1, 23.68, 36.55, 53.26, 613.04, 0.77
1776037, 23.74, 101383.00, 36.40, 12887828.00, 89.93, 1, 23.68, 36.54, 53.36, 613.46, 0.77
1779037, 23.75, 101385.00, 36.41, 12887828.00, 90.12, 1, 23.69, 36.53, 53.45, 613.79, 0.77
1782037, 23.74, 101385.00, 36.44, 12887828.00, 90.30, 1, 23.68, 36.58, 53.52, 614.09, 0.77
1785037, 23.74, 101385.00, 36.44, 12887828.00, 90.46, 1, 23.68, 36.59, 53.59, 614.38, 0.77
1788037, 23.74, 101383.00, 36.44, 12887828.00, 90.61, 1, 23.68, 36.59, 53.66, 614.64, 0.77
1791037, 23.74, 101385.00, 36.45, 12887828.00, 90.74, 1, 23.68, 36.60, 53.72, 614.88, 0.77
1794037, 23.74, 101385.00, 36.45, 12887828.00, 90.88, 1, 23.68, 36.59, 53.78, 615.11, 0.77
1797037, 23.73, 101383.00, 36.45, 12887828.00, 91.02, 1, 23.67, 36.61, 53.84, 615.36, 0.77
1800037, 23.73, 101383.00, 36.43, 12887828.00, 91.19, 1, 23.67, 36.58, 53.91, 615.65, 0.77
1803037, 23.73, 101383.00, 36.42, 12887828.00, 91.36, 1, 23.67, 36.57, 53.99, 615.95, 0.77
1806037, 23.72, 101383.00, 36.40, 12887828.00, 91.55, 1, 23.66, 36.57, 54.07, 616.29, 0.78
1809037, 23.72, 101387.00, 36.41, 12887828.00, 91.74, 1, 23.66, 36.57, 54.15, 616.61, 0.78
1812037, 23.73, 101383.00, 36.41, 12887828.00, 91.88, 1, 23.67, 36.55, 54.22, 616.87, 0.78
1815036, 23.72, 101387.00, 36.38, 12887828.00, 92.08, 1, 23.66, 36.54, 54.30, 617.21, 0.78
1818037, 23.72, 101387.00, 36.40, 12887828.00, 92.25, 1, 23.66, 36.55, 54.38, 617.51, 0.78
1821037, 23.72, 101387.00, 36.39, 12887828.00, 92.42, 1, 23.66, 36.54, 54.45, 617.80, 0.78
1824037, 23.71, 101385.00, 36.40, 12887828.00, 92.60, 1, 23.65, 36.56, 54.53, 618.11, 0.78
1827037, 23.72, 101385.00, 36.38, 12887828.00, 92.76, 1, 23.66, 36.53, 54.60, 618.40, 0.78
As you can see the gas resistance does not change even though the co2 and voc is updated and should be based on the gas resistance?
Note even after several days of running the gas resistance does not change.
All these tests have been run on ESP-32 microcontrollers.
Thank you,
Liam
Hi liamm36,
Thanks for your feedback.
After our internal discussion, it look likes gas is in resistant saturation situation, please check below information,
1.Check the sensor heater if work or not, or use different heater temperature to check.
2.Use another BME680 sensor to check if have same phenomenon.
Hi liamm36,
Do you have further feedback?
Since there was no feedback for a long time, we close this topic first. You could update feedback in the future if you have.