Momentum-Apps

flipperzero-geigercounter

A geiger counter application for the Flipper Zero

You need a geiger counter board to run this application. This board can be used : https://aliexpress.com/item/1005004074447209.html

You also need jumper wires to connect the board on the Flipper Zero.

Note 1 : this board uses a J305 geiger tube. According this website gamma conversion factor is 0.0081 for this tube. This value has been declared in the header of the source file so you can change it easily if needed. Incorrect conversion factor will give false measurements when μSv/h / mSv/y is selected.

Note 2 : J305 geiger tube is only sensible to beta and gamma rays. Alpha rays cannot be detected.

Usable radioactive sources :

• natural uranium (alpha, beta, gamma)
• natural thorium (alpha, beta, gamma)
• radium-226 (alpha, beta, gamma)
• cobalt-60 (beta, gamma)

Unusable radioactive sources :

• americium-241 (alpha)
• polonium-210 (alpha)
• tritium (very low beta)
• high purity metallic uranium/thorium (alpha)

The geiger counter board can be powered with +5V power pin of the Flipper Zero. This pin will automatically be enabled when the program is launched.

Output pin for measure on arduino cannot be used on the Flipper Zero because output voltage is too low. You can use jack out port instead. Just cut audio jack cable and connect audio channel (left, right or both together) with a cut half male jumper wire to A7 GPIO :

Black wire is usually used for the ground (sleeve on the schematic). You can use a multimeter to be sure or simply test other wires.

Global schema :

Build the program

Assuming the toolchain is already installed, copy flipper_geiger directory to applications_user

Plug your Flipper Zero and build the geiger counter :

./fbt launch_app APPSRC=applications_user/flipper_geiger

The program will automatically be launched after compilation

A4 GPIO can be connected on A7 GPIO to test this application without using a geiger tube. A4 GPIO is generating a signal whose frequency changes every second.

Press Ok button to clear the graph, press Left/Right to choose unit (cpm, μSv/h, mSv/y), press Back button to quit

If you don't want to build this application, just simply copy flipper_geiger.fap on your Flipper Zero

Use cases

Ambient radioactivity (descendants of radon gas are detected) :

Note : measures in μSv/h / mSv/y are not precise

Measure of uranium ore piece inside a lead container :

Measure of uranium ore piece (the most radioactive part) in contact with the geiger tube :

Measure of radium dial pointers in contact with the geiger tube :

All previous measures in a row (the scale of the graph is automatically adjusted) :

A4 GPIO on A7 GPIO :

Changelog

• 2023-03-01

  • Usable/unusable sources have been added

• 2023-02-26

  • More clarity about how to connect audio jack cable on A7 GPIO

• 2023-02-02

  • μSv/h and mSv/y have been added
  • 5V pin is automatically enabled when the program is launched

• 2023-01-15

  • Code fix & optimizations
  • More events can be handled without any issue

• 2023-01-09

  • Code fix
  • Global schema was added

• 2023-01-08

  • Initial release