I just set it up with ESPHome and it was very easy!
Very basic code and wiring.
This is the relevant code part of the ESPHome device, an ESP8266:
sensor:
- platform: pulse_counter
pin: GPIO4
name: "Geiger Counter"
update_interval: 15s
EDIT: I fixed the code. I realized that ESPhome calculates correctly the pulse/minute when changing the update_interval from default value.
