I've spent a few days trying to find why I can read TPH, but the ADC value for Gas was always zero.
The datasheet shows the 'run_gas' flag in register 71h (Ctrl_gas_1), bit postion '4'. This is incorrect - it should be bit position '5'.
Hope this saves some time for somebody!!!
Solved! Go to Solution.
Because setting Ctrl_gas_1 register (0x71) to: (BME68X_RUN_GAS_MSK & 0x20).
Produces 'gas_r' readings which vary when I introduce and remove various gases.
Setting Ctrl_gas_1 register (0x71) to: (BME68X_RUN_GAS_MSK & 0x10).
Produces zero every time.