The Mysterious Case of the Disappearing Noise - ESP32 Walkie Talkie Project

We've been hunting for some annoying noise in our Walkie Talkie project and I think we might have cracked it.

We've been hooking up our I2S MEMS microphone (an ICS-43434 breakout board) to an ESP32 TTGO T7_V1.5 board and it's all been working nicely apart from some strange noise we've been picking up.

I've seen this kind of noise on Electret microphones and it's always been due to noise on the 3v3 line - but in this case, I couldn't see any noise on the power lines when transmitting WiFi - so it's been a bit of a mystery.

I think we're now back on track and ready to build the Walkie Talkie software.

One of the channel listeners has also been investigating this problem and has produced a great video here - https://www.youtube.com/watch?v=BkiDfcDYZFQ&t=28s ... https://www.youtube.com/watch?v=zPd5tm6MtfM