Hi, it’s driving me nuts, the calculation of O2 percentage is saying 32% instead of something below 21.5 at sea level.
Hardware
I’m running a Grove O2 sensor (http://wiki.seeedstudio.com/Grove-Gas_Sensor-O2/#connection), connected to an Adafruit ADS1115 (https://learn.adafruit.com/adafruit-4-channel-adc-breakouts/overview).
The sensor has been connected to its board, which I understand starts the ‘preheating’ oxidisation process. It’s been powered and running with a custom particle board via I2C for over 24 hours.
Software
Using the ADS 1x15 library I found on build.particle. I’m running a few different calculations from various sources as what google turned up was other frustrated folk because the board had changed over time and the calculation had changed.
Advice sought
- Anyone got one running with a particle?
- Suggestions on the gain setting for the ADS? Default is
ads.setGain(GAIN_TWOTHIRDS); // 2/3x gain +/- 6.144V 1 bit = 3mV 0.1875mV (DEFAULT)
- Is it just a case of leaving it a few more days to ‘preheat’ ?