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Good morning,

Did anyone managed to have an air quality MQ135 sensor work on the Z-Uno? I have it working correctly on Arduino, but not on the Z-Uno.

With this code: https://create.arduino.cc/projecthub/am ... uno-69805c
I still have 0 as a sensor value.

With this code: https://www.instructables.com/id/Easy-A ... 35Cayenne/
it doesn't compile on the Z-Uno (error in the lib MQ135).

Any idea, please?

Did you power the sensor with 5V?
With 3.3V its not going to work.
You need as well a voltage divider to get output down to 3.3V

https://www.olimex.com/Products/Compone ... -MQ135.pdf

Thanks a lot! I'll do like this and will let you know how it goes.