I have two BME680s running on the same hardware/software platform. One is producing strange oscillations, the other is fine. Is there anything I can do to sort it out? Is it a defective unit? Samples are taken every 60 seconds, using code largely inspired by the Bosch GitHub examples, ie:
/* Set the temperature, pressure and humidity settings */ gas_sensor.tph_sett.os_hum = BME680_OS_2X; gas_sensor.tph_sett.os_pres = BME680_OS_4X; gas_sensor.tph_sett.os_temp = BME680_OS_8X; gas_sensor.tph_sett.filter = BME680_FILTER_SIZE_3; /* Set the remaining gas sensor settings and link the heating profile */ gas_sensor.gas_sett.run_gas = BME680_ENABLE_GAS_MEAS; /* Create a ramp heat waveform in 3 steps */ gas_sensor.gas_sett.heatr_temp = 320; /* degree Celsius */ gas_sensor.gas_sett.heatr_dur = 150; /* milliseconds */ /* Select the power mode */ /* Must be set before writing the sensor configuration */ gas_sensor.power_mode = BME680_FORCED_MODE;
I had question here:
Are those two BEM680 on the same board or on differnet boards?
If on the same board, then you need to double check if the correst calibration parameters used for calculate the output value. Each sensor has their own calibration parameters, you can't just use one for another.
If they are on differnet board, then one board test OK, the other board test with failure, you can consider to do the swap first. if this error is following sensors, then it might be a sensor defect. then you need send that sensor back to us for further analyze.
they are two separate boards. Note that I am using the bme680 api, not BSEC at present.
In terms of swapping the sensors, do you mean to actually desolder them and resolder on a diff board? I _could_ try that I guess, but it's a pain.
I'll check the power rails first and let you know.