BH1750
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claws
Improve error handling
The problem highlighted in this issue is pretty unlikely and has never been reported before so is likely very low priority.
When reading a light value there is a possibility that the data read is not the expected 2 bytes. The implementation assumes that 2 bytes are read, even if they are not, and continues progressing through the function which could then use garbage data in the uninitialised level variable.
Only a happy path is really accommodated for in the implementation and Arduino does not seem to really support error handling (e.g. exceptions). Perhaps we could consider returning a negative number to signal an error - though the existing return value type does not support that. Perhaps in this condition it could return 65535 which is well above the maximum possible lux value (which is raw/1.2 = 54612).
Maybe there is another flaw: If we use H-Resolution Mode2 we get a 0.5 resolution. Therefore we need a float as return value. And in that case we could use negative numbers
I added an else-path at BH1750.cpp:183 with
Wire.reset();
Without this the I2C bus was held down forever. It took me some hours because the problem was not easily reproducible.
Here is the PR https://github.com/claws/BH1750/pull/41
