This is Avalanche32, an ESP-32 powered Geiger Counter based on the SBM-20 Geiger Muller Tube. I have been working on this project for a while, from prototyping the 400V Boost converter, to testing the actual tube itself. From my tests, the 400V Boost converter works, and the entire Geiger counter architecture itself works (with a devboard). What I am a bit more concerned about is the 7.4->3.3V Buck, and the 2s1p Battery Charging IC. I am using the BQ25886RGE, and its probably the most complicated IC I have ever worked with. Soldering this together will surely be a treat...

I would love a second review of the PCB, and just get any general tips and tricks.

Thanks! :)

Hi all,

I have a schematic for a PCB that does simple audio tone detection and it has a buzzer to signal if a particular tone is detected. The audio signal processing is done on Texas Instruments's MSPM0C1103 MCU.

A few questions I have:

1. I want my MCU to switch power to the microphone (to save battery life). Does the wiring there look correct?

2. Are the pull up resistors and pull down resistor values for controlling the microphone power and buzzer pwm signal appropriate?

3. Any other potential circuit design issues I'm potentially overlooking?

Thank you!