Broken microphone on Enviro+ FeatherWing

Support
1

I’ve noticed for a while that my Enviro+ FeatherWing always plots a flat line for mic/sound. I’ve just checked and the standard deviation sits around 55 regardless of audio level in room which suggests it’s just reading electrical noise rather than sound although the level is around 32768 (half way)? I’ve even tried tapping it with same result. Is my microphone broken?

Adafruit CircuitPython 6.0.0 on 2020-11-16; Adafruit Feather nRF52840 Express with nRF52840
>>>
>>> import analogio, time
>>> import pimoroni_physical_feather_pins
>>> import ulab
>>> import ulab.numerical
>>> mic = analogio.AnalogIn(pimoroni_physical_feather_pins.pin8())
>>> samples = ulab.array([mic.value for _ in range(10000)])
>>> ulab.numerical.mean(samples)
32841.8
>>> ulab.numerical.std(samples)
53.2202
>>> ulab.numerical.max(samples)
33088.0
>>> ulab.numerical.min(samples)
32624.0

microphone.py example also doesn’t work but that’s not surprising given the above.

2

got the same situation. How did you deal with it in the end?

3

I didn’t make any progress on the microphone and had almost forgotten about that!

I spent some time making the libraries more robust (PR #8 and PR #24) and am currently distracted by soil moisture and a few other things.

Would be useful to know if anyone has one that works?

4

I just got a new one and it works! I have the plotter example running with interval changed to 1 second. One thing to note is it’s not very sensitive. I can play music nearby and it doesn’t pick it up. If I repeatedly clap above the board I can get 0.20 to 0.30 readings and some points that show up on the plot. Worth checking that then contacting support: Contact Us for Raspberry Pi Technical Support – Pimoroni