Add mask for feature set check.

[caternuson]

Potential fix for #19. Adds mask to only check partial feature set value result.

[caternuson]

@ladyada for review. UNTESTED (don't have any newer variant boards)

[Cardenas-Synth]

thank you for trying to address this. you have the .mpy update for this? i tried using an init.py version on my esp32 and i'm getting this error after that line of the feature passes (BTW, thank you for looking into this):

File "", line 1, in
File "/lib/adafruit_sgp40/init.py", line 123, in init
File "/lib/adafruit_sgp40/init.py", line 146, in initialize
File "/lib/adafruit_sgp40/init.py", line 293, in _read_word_from_command
OSError: [Errno 116] ETIMEDOUT

[caternuson]

Using the .py version is OK. The .mpy is just a "compiled" version that helps for memory constrained boards. If the .py imported without errors, then it's working. You'd want to remove the .mpy version from the CIRCUITPY lib folder though, since .mpy has import precedence over .py.

The ETIMEDOUT issue may be indicating there is more going on. :(

[Cardenas-Synth]

Great to know! Thank you for responding so quickly.

In case this helps, my team has ordered from digikey/adafruit about a couple months back and all spg40s (~10) operated smoothly. We recently ordered from mouser/digikey and all of the boards (16 boards) all failed. Currently, the older ones we still have still work, the newer ones do not. Possibly a bad PCB print? we're returning the ones that didnt work. The position we're at is time sensitive, so we plan on attempting to order some more from a source capable of overnighting to see if we have better luck

Thanks!

Damon

[ladyada]

@caternuson can merge this to at least resolve the feature change. do you wanna pick up an SGP40 from the shop to try and repro the timeout

[caternuson]

@ladyada yep. will do. will wanna check arduino also.

[Cardenas-Synth]

I believe i resolved the issue (for at least the code for circuitpython bundle for esp32...maybe similar for RPI)! Please double check, though. I have not verified compatibility with older chipset nor have i fully vetted impact on readings (i assume there will be none, so far it looks good).

With the new chipset, the timeout : self_test = self._read_word_from_command(delay_ms=250)
needed to be extended to 500ms. This was changed with a note in the arduino code (see link below) but not in the circuitpython init.py script. I made the update and my code works now! (*Note, you also have to broaden the acceptable chipsets in another line)

I changed lines 140, 146, and 207 to the following:
{{
140| if featureset[0] & 0xFF00 != 0x3200:
146| self_test = self._read_word_from_command(delay_ms=500)
207| read_value = self._read_word_from_command(delay_ms=500)
}}

I changed the time instance in two locations, although i dont know if both are necessary.

Arduino Change notes
adafruit/Adafruit_SGP40@14449d7

[ladyada]

oh yeah that does sound familar! ok new PR made, please take a look!
#21