top of page
Arduino IDE Geiger Counter Kit with LCD

Arduino IDE Geiger Counter DIY Kit ver.2 with LCD; w/o GM Tube


Arduino IDE DIY Geiger Kit ver. 2.00 RH-K-GK-2-A with UART logging.

This is updated version 2.00 of our simplest Geiger Counter project based on Arduino IDE. All parts in the project are through-hole easy to solder. With your package you'll receive detailed printed electrical circuit to assemble the board. Microcontroller comes pre-programmed, but if you want to get source files please contact us by email to get the link for downloading files. 

We made several improvements in electrical circuit and Arduino program to upgrade this kit to the new level. Optimized code with true voltage feedback on high voltage make this project much more stable for serious experiments. With a good quality Geiger Tube (like LND-712) you can test very active samples and get maximum count rate as your tube is possible to go up.

The kit supports UART logging of CPM value and can be integrated into environment monitoring project. 

Technical specifications:

  • High Voltage PWM Converter with true voltage feedback

  • HV Converter has ability to drive 20M load, 25uA into 500V max.

  • 400V and 500V Geiger Tubes are supported

  • Dose-Rate Calculation and CPM counter

  • New Logarithmic Bargraph with CPS counter

  • Two tact buttons for controlling the software

  • Moving Average CPM calculating algorithm

  • UART logging with "Radiation Logger", require USB-TTL dongle

  • Clicker Geiger Event Sound with Mute and Two LED's

  • Supply Voltage: 5V DC

  • Supply Current: 15mA at background level

  • Dimensions: 89(L) x 39(W) x 22(H) mm

  • Shipping Weight: 180gr

  • UPC Number: 634654895707

  • SKU: RH-K-GK-2-A

The newest version 2.00 of Arduino IDE Geiger Counter Kit from RH Electronics! The board is miniature PCB with through-hole parts and Atmega-328A microcontroller with installed Arduino IDE bootloader. The kit comes with detailed electrical circuit and pre-programmed microntroller. If you want to get source files you can contact us by email to receive the download link.


What is new in this version?

  • Well-designed electrical scheme and improved PCB layout

  • True voltage feedback in PWM high voltage converter that allows now to drive 20Mega ohm load on 500V

  • Optimized software for fast count-rate condition

  • Second screen mode with CPS counter

  • Fast CPS bargraph with logarithmic scale (great for pancake tube or scint.probe)

  • Native support of 500V and 400V tubes, voltage is set with jumper switch

  • Two LED's with buzzer clicker and mute button

  • Switch between CPM or CPS screen with button


The kit is robust hardware that designed to drive a Geiger Tube while high voltage and pulse counting are controlled by one microcontroller. This is simple and educational project, however load capability and performance of the circuit allows to use this board also in more serious applications, like scientific research or extreme enthusiast tests. Second CPS screen mode with bargraph can be used with sensitive pancake GM tube or with externally connected scintillation probe. 

As the previous version it still has:

  • Dose-Rate calculation and ability to calibrate through Arduino sketch

  • Moving average CPM counter UART Logs of CPM value every 10 seconds

  • 16x2 LCD Screen

  • Friendly Arduino IDE source files, open source with buyer




Unlike the previous edition ver.1.00 RH-K-GK-1-A  that was limited in maximum count rate, the new version 2.00 RH-K-GK-2-A is able to work at the maximum count-rate your tube is able to provide. We tested it with LND-712 new tube and DP-2 Sr-90 source back to back where maximum CPS reading was recorded is 5000 CPS (300K CPM on LND-712). The DP-2 Sr-90 test source is known as one of the hottest test sources that usually cause old stock tubes like SBM-20 to ignite and enter current mode. So if you planning to run the counter in extreme contidion please be sure you have a new quality tube that able to work on it's maximum count-rate.

Measuring and adjusting high voltage:

Default PWM settings in software should work fine for both modes: 400V or 500V. If required, you can adjust PWM percentage ratio through sketch update. The kit has installed 10Mega ohm load resistor with output on terminal block. When you apply 10Mega ohm voltmeter on terminal block then load resistor creates voltage divider with internal impedance of voltmeter. That's why 400V will read as 200V and 500V will read as 250V. Total maximum allowed load on 500V is 25uA. 


To switch 400V/500V settings of PWM set Jumper-1 and restart the power of the kit. With jumper installed it has 500V output, with jumper removed it has 400V output.


Compatible Geiger Tubes:

Default software settings of gamma doserate are for SBM-20.If you struggle to deal with Arduino IDE sketches please let us know when you purchase in PayPal comments of your order and we'll set the gamma coefficient for different tube you have.Usually the coefficient can be extracted from tube datasheet, in the PDF manual you can find the most commond values. Some old stock tubes hasn't any useful doserate conversion information in their datasheet, in that case we'll use default SBM-20 settings.

The kit supports following GM tubes: SBM-20, STS-5, SBM-19, LND-712, LND-7312, SBT-9, SBT-11A, SI-180G, Philips 18504, Beta-1, Beta-2, Gamma-7C, Vacutec-70019A and more. 


Purchase Include:

  • High Quality PCB Board

  • 16x2 LCD Screen

  • Electronics components with detailed electrical circuit

Arduino Counter Kit sold without a Geiger tube, but you can add SBM-20 or STS-5 GM Tube to your shopping cart.

The kit can be pleasure to solder even for a beginner. Electrical circuit design made simple and clear as possible. If you need assembled version then for additional cost you can purchase soldered version of the kit, please tick "Soldering Service" option before you add it to the cart.

If you need Geiger tube, we offer tested samples of SBM-20 tubes that comes from trusted old stock supplier and passed our quality control tests. These tubes usually can count up to 180K CPM before internal gas discharge force ignition current mode.

3D designed Enclosure:

Special thanks to Marc for sharing his project - Arduino Geiger with LND7231 tube. You can download it here:

    bottom of page