Geiger counter RadiationD v1.1 (CAJOE)

With the help of Pulse Counter Sensor and the RadiationD v1.1(CAJOE) you can make your own Geiger counter, which will give you a more or less precise messurement of the current radation level. But it should be good enough to warn you about critical events.



The first step is to connect the sensor.

You just need to connect the +5V, the ground and a GPIO pin to the ESP. In my case I used the pin 34 for the signal. (The print on the PCB is wrong VIN is the signal.) This setup should give you the pulse of each messurement or count. For more information check the Video of Andreas Spiess.


I just 3D printed an small housing the avoid touching the high voltage Geiger Mueller tube. Counter Tube Case (The tube should not be in direct sunlight. So maybe you will need another case.)


The block Pulse Counter Sensor will count the radation events per minute. With the found specs of the tube you will be able to calculate the radiation in μSv/h.

It’s just the counts per minute (CPM) times the factor of your Geiger Mueller tube you’re using. It should be the J305ß, which comes with the PCB. (To make sure - check your printing on the tube)

μSv/h = (CPM - Tube noise) * Factor According to the video of Andreas Spiess the tube should have about 12 CPM as background noise.


The current version of the pack comes with the J305ß Geiger tube which detectes Beta and Gamma radiation. Specifications: Manufacturer: North Optic Radiation Detection: β, γ Length: 111mm Diameter: 11mm Recommended Voltage: 350V Plateau Voltage: 360-440V Sensitivy γ (60Co): 65cps/(μR/s) Sensitivy γ (equivalent Sievert): 108cpm / (μSv/h) Max cpm: 30000 cps/mR/h: 18 cpm/m/h: 1080 cpm/μSv/h: 123.147092360319 Factor: 0.00812037037037


  - platform: pulse_counter
    pin: 34
    name: "Radiation"
    unit_of_measurement: 'μSv/h'
     rising_edge: DISABLE
     falling_edge: INCREMENT
      - offset: -12.0 # J305ß Geiger Mueller tube background noise 0.2 pulses / sec x 60 sec = 12 CPM (Counts per Minute)
      - multiply: 0.00812037037037 # Factor: 0.00812037037037

See Also