BME680 module initial commit

[vsky279]

Fixes #2114.

Make sure all boxes are checked (add x inside the brackets) when you submit your contribution, remove this sentence before doing so.

• 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/en/*.

This is a simple driver of the Bosch's BME680 sensor. In addition to the BME280 it is able to measure the indoor air quality. Unfortunately the IAQ (Indoor Air Quality) Index calculation algorithm is not publicly available. So we need to live with the gas resistance value which should still be some proxy to the IAQ.

Definitely it would be good if someone can further test the module before it is merged.

[marcelstoer]

What is this copyright for?

[vsky279]

I'm using parts of the bme680.c driver from Bosch - it says we should retain the copyright. I think maybe just one line should be enough.

[marcelstoer]

I saw that, yes. However, I thought leaving the copyright in the source code would be enough. It feels somewhat out of place here and makes it look like Bosch contributed the NodeMCU module (and wrote this documentation).

[vsky279]

This seems reasonable. I will make a block in the code with these functions and will put the (c) note there.

[marcelstoer]

it would be good if someone can further test the module

I'm afraid that due to lack of hardware this will probably not happen. However, a code review can still be conducted.

[pjsg]

I see that this uses doubles to perform calculations... Does this work in an integer build?

[vsky279]

Yes, it does. This is even tested in the BME280 module.