Pomelo is a complete instrument for hobby-level gamma spectroscopy. It is built around the Pomelo Core and Physics which handle all the radiation detection, but adds a user interface and ample communication in the form of an Arduino-compatible ESP32-C6 add-on board, the Pomelo Zest.

Pomelo Zest board displaying a Th-232 spectrum in logarithmic scale

The Pomelo Zest features:

A brief user interface demo of the instrument is shown in the following video.

The Pomelo Zest can be used as a generic ESP32-C6 development board, but its mechanical design is built to match the Pomelo Core and Physics so it might not be optimal because of the battery and power button placement.

Block diagram

Detector block diagram showing available connectivity for the system components. The Pomelo Core can still be accessed from a computer through USB for control and firmware update even while it also connected to the Zest

The software on the Pomelo Zest is written in the Arduino environment so it is very easy to follow and modify, but not optimized for low power consumption. However, the Pomelo Core stays powered when the Zest is switched off, so data can still be accumulated using little power.

Schematic

Pomelo Zest schematic