Sensor driver for BME680 sensor - update to version 3.5.9

[vsky279]

Fixes #2944.

• This PR is for the dev branch rather than for master.
• This PR is compliant with the other contributing guidelines as well (if not, please describe why).
• I have thoroughly tested my contribution.
• The code changes are reflected in the documentation at docs/*.

Solves the issue where the air pressure, humidity and gas resistance are not compensated during ambient temperature changes.

Updates the Bosh BME680 driver from version 3.5.1 to current version 3.5.9.

[marcelstoer]

@Michal78S it would be great to get your confirmation that this fix solves the issue. Can you build a firmware from @vsky279's branch for testing?

[vsky279]

I agree that it is good idea to know whether it solves @Michal78S's issue.
But even if it doesn't we should merge as it upgrades the driver and solves the same issue in my case.

[Michal78S]

It is an honor for me, but since I have started nodemcu i build firmware with cloud builder...

[vsky279]

@Michal78S What modules do you need? I will compile the fw for you. Floating version?

[Michal78S]

The standard modules: GPIO, net, node, timer, uart, wifi and of course i2c, BME680.
The open issue is IAQ. Is it possible to add it to BME680 module? There is on the market one solution which uses STM32 and Bme680 and provides both: IAQ index and gas resistance.

[vsky279]

Please find the compiled module here: https://github.com/vsky279/bme680_bin/blob/master/nodemcu_float_bme680_20191203-0946.bin.

The issue with IAQ calculation is that the algorithm has not been published by Bosh. Please see module documentation:

This module is able to measure the gas resistance (see Bosch's datasheet). The gas resistance is not the IAQ (Indoor Air Quality) Index. But apparently it can be used as some proxy. The value still should somehow reflect the air quality. It seems that the higher value the air quality is better.

The algorithm for IAQ calculation from the gas restistances (probably measured at different temperatures) is not publicly available. Bosch says that at this point of time the calculations for the Indoor Air Quality index are offered only as a pre-compiled library (see discussion here: BoschSensortec/BME680_driver#6). It is available as the BSEC Library. The algorithm is implemented in the library bsec/algo/bin/ESP8266/libalgobsec.a. Unfortunately I did not even manage to run the Bosch BSEC example on ESP8266 using this library.

If you find somewhere module implementing IAQ calculation then we can replicate it here.

[shimosaurus]

I made the Lua code for reading data from module GY-MCU680V1 with sensor BME680 and STM32. It reads IAQ and gas resistance values: https://github.com/shimosaurus/mcu680

[marcelstoer]

@shimosaurus Woah, you even used our documentation template in your README 😄 Great job. Is that really all the code it takes? Were your inspired by this gist https://gist.github.com/xxlukas42/a878f5c44f1ec108a460e9b9500b79f5 ?

[vsky279]

I made the Lua code for reading data from module GY-MCU680V1 with sensor BME680 and STM32. It reads IAQ and gas resistance values: https://github.com/shimosaurus/mcu680

Have you tested it? I can't imagine this can be the way to get the IAQ value. Bosch's documentations says the IAQ calculation is made available through the BSEC library which is not open-sourced.

The code you provide is a bit weak as the commands sent to the sensor are not documented.

[Michal78S]

I made the Lua code for reading data from module GY-MCU680V1 with sensor BME680 and STM32. It reads IAQ and gas resistance values: https://github.com/shimosaurus/mcu680

Nice job :) but it works only with module GY-MCU680 where are STM32 and BME680. Main job and calculations provides STM32. This solution has groving number of ussers because is one of few available so adding Lua code for it is good idea.

[shimosaurus]

@shimosaurus Woah, you even used our documentation template in your README smile Great job. Is that really all the code it takes? Were your inspired by this gist https://gist.github.com/xxlukas42/a878f5c44f1ec108a460e9b9500b79f5 ?

I was inspired here: https://forum.mysensors.org/post/94736 but @xxlukas42 used probably the same source.

Have you tested it? I can't imagine this can be the way to get the IAQ value. Bosch's documentations says the IAQ calculation is made available through the BSEC library which is not open-sourced.
The code you provide is a bit weak as the commands sent to the sensor are not documented.

As @Michal78S wrote - my code doesn't count IAQ, but reads "only" the STM32 output on the GY-MCU680 board where BSEC is running. But as long as the BSEC library is closed-source, this solution is a way to obtain IAQ values ​​into the NodeMCU Lua.

My comment was not directed mainly to this pull request but to query @Michal78S how to get IAQ values.

[vsky279]

My comment was not directed mainly to this pull request but to query @Michal78S how to get IAQ values.

Oh, I see that puzzled me.

[Michal78S]

I can confirm, new BME680 driver works better. I got the same readings of pressure from BME680 and BME280. During weekend I'm going to make outdoor tests (wider temp. range).

Other importatnt thing is @shimosaurus solution. Many NodeMCU users don't konow about it, so how about add it to the cloud builder?

[marcelstoer]

...@shimosaurus solution. Many NodeMCU users don't konow about it

Jan could make a PR to have the script hosted at https://github.com/nodemcu/nodemcu-firmware/tree/master/lua_modules - that's up to him. It would then also show up under the Lua modules at https://nodemcu.readthedocs.io/en/latest/.

so how about add it to the cloud builder?

Contrary to C modules Lua modules are not built into the firmware binary. You need to provision them separately via SPIFFS or LFS.

[Michal78S]

Checked. New driver gives stable and reliable readings air pressure from BME680. Yesterday in the afternoon pressure rapidly dropped. It was registered by BME680, and values are near identical with the forecast and readings from BME280 and amateur weather station.