@piconomix wrote:
I suspect that my Makefile did not pick up the change to the "bsec_serialized_configurations_iaq.c" file and used an old object file. After fixing it, the BSEC lib expects to be called every 300 seconds.
Good to hear 🙂
@piconomix wrote:
Why does the IAQ value vary so much between readings?
Honestly hard to say from 3 data points, and without knowing the environmental conditions during the 15 minutes observed here. What I can tell from this little amount data is that:
The IAQ is reacting to stimuli in the raw rag resistance signal, thus it seems to behave as expected,
It looks like IAQ accuracy is still at 1. This typically indicates that BSEC hasn't experienced significant enough stimuli (yet?), thus the self-calibration status is uncertain and could explain such variations. If the second value shows sIAQ with less significant variations, this could consolidate this hypothesis.
@piconomix wrote:
If we were not interrested in IAQ, because of the excessive calculation burden, but only eCO2 and VOC, would there be a simpler formula / procedure available to calculate it from the gas resistance?
Which outputs are enabled will not impact the integration efforts. In fact, eCO2 and bVOC eq are derived from the sIAQ output, thus the same internal calculations would still be needed.
@piconomix wrote:
FYI: we are using the BME680 in a battery powered IoT device that must take a measurement and send an RF packet with the data to a gateway that relays the info to a server. It is vital that the device's battery last as long as possible.
Since you mention it, a valid integration is also to collect only raw BME680 data at the edge, and run BSEC in your gateway or server. Of course of the BME680 needs to be operated with the appropriate settings, and an absolute timestamp is still mandatory. If BSEC outputs are still needed at the edge (e.g. to be displayed on a screen), you would need to consider how to stream the relevant data back to your device though. Pros and cons must be defined for your specific use-case.
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