Purpose

GGreg20_V3 Ionizing Radiation Geiger Counter is an electronic sensor module for building a personal counter of ionizing radiation level. For this purpose, the detector has an impulse counting output to the main controller. Arduino, Adafruit, ESP8266, ESP32, and others can be used as a host controller.

The radiation level is indicated by light and sound signals. The user can mute sounds (jumper J1 - buzzer on/off).

GGreg20_V3 is an inexpensive and useful device for checking the “purity” of:

• mushrooms,
• berries,
• vegetables,
• firewood, etc.

This module is useful for creating smart measurement devices for determining the power of ionizing radiation indoors or outdoors, and is available in both portable/pocket style and stationary mode. The only thing you need to start measuring ionizing radiation with the GGreg20 is any microcontroller that can count the number of pulses per unit time on GPIO.

Specifications

• Module dimensions - 30 x 126 x 12 mm. Weight 30 g.

• Power supply:

  • a rechargeable battery or a battery: 1 cell Li (3.7V) battery, 2 cell Ni (2.4V) battery, 3 cells (4.5V) battery connecting to port "Bat";
  • a 5 Volt charger.

• Power supply of the SBM-20 tube is a built-in adjustable high voltage DC-DC converter. The target voltage level of 400 V is regulated by a potentiometer. The module is fine-tuned and ready for use.

• The module also works with the J305 tube and there is an option to choose a configuration with this tube when ordering.

WARNING! From September 1, 2022, the function of high voltage regulation has been removed. The voltage level of 400 volts is fixed by hardware means. At the same time, if you need a module with high voltage regulation for your project, please consider the module DCDC_3V3_400V_V1: High Voltage Module

February 2023 Update: The feedback we receive from customers about the planned implementation of the changes has led us to the decision not to rush to fix the voltage level on the module, as this limits the possibility of using other tubes compatible with the module. Therefore, we have decided not to make any changes at all and are supplying the module in its original configuration.

• Consumption current - 18 mA at 5V or 30 mA at 3.7V via LiIon.
• GGreg20_v3 is compatible with the ESP8266/ESP32 logic signal levels (3V3 ACTIVE-LOW: 3 to 3.3V HIGH and about 0.7V LOW), and will work even with the 5V logic input.

Dimensions and Pin assignments

GGreg20_V3 module pin assignments are as follows:

• BAT - Power supply input 2.2V - 5.5 V;
• ON/OFF - Main switch on/off;
• OUT - Pulse output, active-low;
• BUZ - Buzzer enable jumper.

The dimensions of the GGreg20_V3 module are as follows:

• X: 126 mm;
• Y: 30 mm;
• Z: 12 mm.

Differences and compatibility with previous versions of GGreg20

Note 1 The GGreg20_V2 module version has not been included in the comparison because it was developed for other design solutions (and did not provide space for the SBM-20 tube on the module board).

Note 2 The module board has a default protection diode against erroneous pole reversal when connecting the battery. Such protection will be appropriate despite the fact that it slightly narrows the voltage range of the input power supply which will be 3-5.5 volts.

Note 3 If you want to power the GGreg20_V3 from a 2.4 volt source, you need to short the Schottky diode shown in the photo with a wire or replace it with a 0 ohm resistor. Note, however, that such a correction will disable the module's reverse polarity protection.

Switching-on and measurements

This module is ready for use. The GGreg20_V3 modules are adjusted, configured and tested for compliance with the declared technical data before being shipped. Any adjustments or settings made by the customer may damage the module or introduce technical inconsistencies.

Connect the power input from the selected power source.

Turn on the power supply. After 10-15 seconds, you will hear a sound and see light signals when the active particles enter the tube.

At normal background radiation, the tube registers and generates 20-30 pulses per minute. The number of pulses can vary depending on weather or cosmic radiation. Consider the average number of signals per minute.

If you receive more than 60 signals per minute, be careful: your detector has “felt” a dangerous level of ionizing radiation from the environment or food, mushrooms, wood, etc

In short, the formula is simple: you need to accumulate the number of ingoing GPIO pulses per minute and then multiply by a factor. Like this:

microsieverts per hour = (impulses per minute) * 0.0092

where 0.0092 is a coefficient obtained from the tube manufacturer's documentation.

Tubes can vary (+ -20%), so we recommend using a conversion factor of 0.0054 to 0.0092 and calibrating the calculations with a trusted (certified) device.

Note: The differences between the tubes are: conversion factor for J305 is 0.00812, deadtime: 180 microseconds. Drivers and examples for SBM20 are compatible, but require replacement of the specified coefficients. It is recommended to operate the tube in a casing, as its bulb is transparent and measurements may be affected by photons of sunlight and similar factors.

Product kit sets

GGreg20_V3 basic

1. GGreg20_V3 module --- 1 pc.

GGreg20_V3 basic and SBM-20 or J305 tube

1. GGreg20_V3 module --- 1 pc.
2. SBM-20 or J305 tube --- 1 pc.

Connectors (installed) and cables

1. Connectors JST XH 2P male straight --- 2 pcs. for installation on the module board;

2. Pulse output cable 15 cm with connectors --- 1 pc:

   • JST XH 2P female on one side and;
   • Dupont 2x1P female on the other side.

3. Power supply input cable 15 cm with JST XH 2P female connector on one side --- 1 pc.

GGreg20_V3 Case 3d-printed option