MultiGeiger Documentation


What is MultiGeiger?

The MultiGeiger is a radioactivity measurement device.

Main features

multiple use cases supported

  • fixed location stations (data transfer via network)
  • mobile operations (using the OLED display and speaker)
  • (more are planned)

multiple 400V Geiger-Mueller tubes supported

  • big, sensitive tubes, like the Si21g or Si22g (for measurement stations)
  • smaller, less sensitive tubes, like the SBM21 (good for finding hot spots)


  • low parts count, simple to assemble
  • inexpensive, but still good parts
  • using ESP32, a modern and fast 32bit micro controller
  • with WiFi (WPA2) or with WiFi + LoRA
  • with OLED display


  • implemented in C
  • using the popular arduino API
  • over-the-air firmware updates

Network and Community

  • this is an Ecocurious citizen science project
  • web-based geo map for publishing measurements
  • web-based archive of historic radiation data

Free and Open

  • GPL v3 licensed
  • open development and issue tracking on GitHub