This is a forked firmware for Cajoe Geiger counter boards to be compatible with GMCServer
Original README:
Arduino project to count pulses from an 'Arduino compatible' Geiger counter radiation detection kit.
- geiger: geiger counter using an AVR-based Arduino, transmitting counts using a NRF24L01+ transceiver
- geiger_esp: geiger counter using an ESP8266, sending counts directly over wifi using MQTT
The particular geiger counter board that this was developed with is: https://github.com/SensorsIot/Geiger-Counter-RadiationD-v1.1-CAJOE-
The counter is connected to a Wemos D1 mini ESP8266 board using the 3-pin connector (Vin, +5V, GND) The Wemos D1 mini receives the tick and power signals from the geiger board on pins D4, GND, +5V. Take care to wire it up correctly, there is a twist in the three wires from the Geiger board to the Wemos D1 mini.
Resistor R19 (470k) was bypassed with a 1k resistor to get a more reliable reading on the ESP8266. A side effect is that you can hear the counter tick while the ESP8266 is being programmed.
See also https://revspace.nl/Geigercounter