Momentum-Apps

flipperzero-geigercounter

☢☢ A geiger counter application for the Flipper Zero ☢☢

(banner has been made with Midjourney)

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 Sv or Rad 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)
• iodine-131 (beta & gamma)

Not really usable radioactive sources (must be in contact with the geiger tube to be detected):

• americium-241 (alpha & low gamma, some strong beta/gamma rays are emitted during radioactive cascade or due to the presence of radioisotope impurities)
• high purity metallic uranium/thorium (same as am241)

Totaly unusable radioactive sources:

• polonium-210 (pure alpha)
• tritium (very low beta)

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:

UI of the application:

CPS: counts per second (instantaneous measure of the radioactivity). CPS is alway displayed on the left corner.

CPM: counts per minute (the sum of CPS over a period of one minute). Other units of measurement can be chosen with Left/Right.

New CPS bar measure appears on the left every second.

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.

Button assignments:

button	function
Ok [long press]	Clear the graph
Left/Right [short press]	Choose unit on the right corner (cpm, μSv/h, mSv/y, Rad/h, mRad/h, uRad/h), cps on the left is always displayed
Up [long press]	Enable/disable recording, led of Flipper Zero is colored in red when recording
Up/Down [short press]	Zoom/unzoom
Down [long press]	Display version of the application
Back [long press]	Exit

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

Build has been made with official toolchain, API Mismatch error may appear if you are using custom firmware. You can bypass this error but the program may crash.

Use cases

Ambient radioactivity (descendants of radon gas are detected, not radon itself):

Measure of uranium ore piece inside a lead container:

Note: measures in Sv or Rad are not precise

Measure of uranium ore piece (the most radioactive part):

Measure of radium dial pointers:

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

Measure of uranium orange pottery:

Measure of americium-241 button from a smoke detector (descendants of americium or radioisotope impurities are detected, not americium itself):

A4 GPIO on A7 GPIO (to test this program without a geiger tube):

Zoom levels (the third picture is the default zoom):

Version of the application (press down button during 1 sec to display version):

Recording function

Output CSV files are stored at the root of SD card. Date & time are set in the name file (example: geiger-2023-07-03--23-48-15.csv)

Data sample:

epoch	cps
0	10
1	14
2	8
3	11
4	9

Atomic Dice Roller

I maintain another application that uses the geiger board to roll dice by using radioactivity: https://github.com/nmrr/flipperzero-atomicdiceroller

Gallery/video of the community

BRD8 [Reddit] - https://www.reddit.com/r/flipperzero/comments/110062z/am_i_a_hacker_now_mom/:

Funbob235 [Reddit] - https://www.reddit.com/r/flipperzero/comments/13m1qly/testing_of_the_geiger_counter/:

Axewarior [Reddit] - https://www.reddit.com/r/flipperzero/comments/14krjs2/gieger_counter/

Seanclark2409 [YouTube]:

Boboso5676 [YouTube]:

Talking Sasquach [YouTube]:

What's next ?

Here are some nice ideas to improve this app:

• Save output data in XML / JSON file DONE ! Output data are stored in CSV (lighter than XML / JSON and easier to parse)
• Use the geiger board as random number generator DONE ! A separate project uses the same geiger board to roll dice: https://github.com/nmrr/flipperzero-atomicdiceroller
• Send data on the air in real time to monitor remotly
• Buzz when it gets dangerous like a dosimeter

Changelog

• 2023-08-06

  • Code optimization (shift operation on CPS array has been removed)
  • Version section has been added

• 2023-07-03

  • Data recording function has been added

• 2023-06-25

  • Add zoom capability
  • User gallery has been added

• 2023-06-08

  • Bug fix

• 2023-04-11

  • More usable/unusable sources
  • Rad unit has been added
  • Code refactoring by replacing old mutex call by new method

• 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 now 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 has been added

• 2023-01-08

  • Initial release