Temperature Accuracy BME688

[JacRob]

Hi all,

I did my first measurements with the BME 688 Dev-Kit and noticed that the measured temperature is quite high. Instead of getting around 22°C (room temperature) the sensors measured between 42-45°C.

I can imagine it is because of the heating gas sensors. Unfortunatelly there is no heater profile with room temperatures. Is it possible to customize the heating profiles or may turn it off completely?

Best,

Jac

[Minhwan]

Hi Clemens, 

As long as you are using BSEC library, you don't have to care about BME688 mode in BME688 API since all things are controlled by library. 

Thank you. 

[jducas]

Clemens,

What you suggest seems reasonable. I would think the required heater sleep period would be a variable based on the thermal characteristics of the PCB.  This could be predetermined through testing and applied as a constant to set the sleep period.  If the period is relatively quick, the temperature could be measured in real time to determine the point of stability before applying as a control reading.  In my application (HVAC room monitoring and control) temperature would have to take priority over PM and GAS detection, so the cool down period would have to be fast to maintain room temperature.  A small fan could accelerate this.     

[Clemens]

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@Minhwan wrote:

As long as you are using BSEC library, you don't have to care about BME688 mode in BME688 API since all things are controlled by library. 

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That means the BSEC library uses the forced mode, by default or is there a flag for switching between forced and parallel mode?

[Minhwan]

Hi Clemens, 

It means that BSEC lib calls bsec_sensor_control function in running state and it decides op mode as below. 

Forced mode 

Parallel mode

Sleep mode

You don't need to select or decide op mode manually. 

Thanks,