Read the BME680 sensor with the BSEC library on Linux (e.g. Raspberry Pi)
Working example of fully using the BME680 sensor on Linux (e.g. Raspberry Pi) with the precompiled BSEC library, which allows to read calibrated environment values including an actual Indoor Air Quality (IAQ) score.
It makes use of Bosch's provided driver and can be configured in terms of it. Readings will be directly output to stdout in a loop.
Includes edits from BME680 using the official Bosch Sensortec BSEC Library
Download the BSEC software package from Bosch wget https://www.bosch-sensortec.com/media/boschsensortec/downloads/bsec/bsec_1-4-7-4_generic_release.zip
and put it into ./src, then unpack unzip bsec_1-4-7-4_generic_release.zip.
Optionally make changes to make.config.
Depending on how your sensor is embedded it might be surrounded by other
components giving off heat. Use an offset in °C in bsec_bme680.c to
compensate. Current value for my setup is 0.8 °C:
#define temp_offset (0.8f)
To compile: ./make.sh
Output will be similar to this:
$ ./bsec_bme680
{"IAQ_Accuracy": 0,"IAQ":25.00,"Temperature": 21.71,"Humidity": 39.26,"Pressure": 1009.72,"Gas": 96989,"bVOCe ppm": 0.5000,"Status": 0}
{"IAQ_Accuracy": 0,"IAQ":25.00,"Temperature": 21.71,"Humidity": 39.21,"Pressure": 1009.66,"Gas": 98240,"bVOCe ppm": 0.5000,"Status": 0}
{"IAQ_Accuracy": 0,"IAQ":25.00,"Temperature": 21.71,"Humidity": 39.23,"Pressure": 1009.68,"Gas": 98240,"bVOCe ppm": 0.5000,"Status": 0}
- IAQ (n) - Accuracy of the IAQ score from 0 (low) to 3 (high).
- S: n - Return value of the BSEC library
It can easily be modified in the output_ready function.
The BSEC library is supposed to create an internal state of calibration with
increasing accuracy over time. Each 10.000 samples it will save the internal
calibration state to ./bsec_iaq.state (or wherever you specify the config
directory to be) so it can pick up where it was after interruption.
The output of the sensor can easily be sent to MQTT using Mosquitto
First, install Mosquitto Client sudo apt-get install mosquitto-clients
Launch the program and send the standard output to your Mosquitto broker
./bsec_bme680 | mosquitto_pub -h 192.168.1.XXX -u "your broker user" -P "your broker password" -p 1883 -t home/pizero/bme680 -l
This can be automated launching bme680_mosquitto.sh using crontab, with the below command
@reboot bash /home/pi/bsec_bme680_linux/bme680_mosquitto.sh >> /home/pi/bsec_bme680_linux/log 2>&1
You can find a growing list of tools to further use and visualize the data here.
Your bsec_iaq.state file might be corrupt or incompatible after an update of the BSEC library. Try (re)moving it.