Gamma Spectrometry Forum

Hi everyone,

I’ve put together a small open-source gamma spectrometer project for the ESP32 "Cheap Yellow Display" (a popular "arduno ESP32 board" with a touchscreen that cost about 15 euros).
It uses a Theremino PMT Adapter with a cheap I2S ADC board, and displays the spectrum, pulse view, and basic oscilloscope directly on the touchscreen. It also includes simple filtering options, CPS display, RGB led activity indication, and a short beep option :) on detected pulses.

This is still a modest experimental project, but it may be useful to others who want to try a compact ESP32-based gamma spectroscopy setup.

Code and documentation are available here:
https://github.com/sylvainf/ESP32-Gamma-Spectrometer
Feedback, corrections, and suggestions are very welcome.

Nice job,

Many years ago I was also playing around with an Arduino, I made this budget version of a spectrometer.

https://www.youtube.com/watch?v=qcwWh61sAhw

It was just a fun project and a completely useless display.

Steven

Thanks Steven — neat setup! The UI is really nice.
On my side it’s a bit different. I’m using the Arduino framework for the software, but running on an ESP32, which is way more capable than a typical Arduino board. You get dual cores and proper floating-point support, so you can start doing some fairly serious signal processing. By the way, I’m pretty happy with the trapezoidal filter, it seems to be working nicely on the pulses.
Also, the ESP32 has I2S bus channel that made possible to hook up a fast good quality ADC. With DMA handling the data stream, the CPU doesn’t have to babysit every sample, which is great for keeping things efficient :).

Hi everyone,

I’ve just uploaded a new version of my small ESP32/CYD gamma spectrometer project.

This update adds a few useful spectrum display features:
- two-point energy calibration
- bin or keV display mode
- optional smoothed spectrum curve over the raw histogram
- automatic peak markers
- LogX / LogY display options
- separate toggles for raw bars and smoothed curve display
- persistent spectrum settings stored on the ESP32

The project is still experimental and very much a hobby build, but it is becoming more usable...