This is the second Geiger counter I have purchased from Granz Scientific; the previous one being the Raspberry Pi based ‘Mk 1’.

After initial power up, the process of using my iPhone to attach to its ‘temporary’ SSID and entering my home WiFi credentials was easy and quick.

Home assistant found it and after entering the key, all was up and running. Don’t forget the key is held in the yaml file that is linked on the Tindie page for the product.

Jan Albert | June 19, 2025

The perfect Geiger counter for sensor enthusiasts

For WiFi IoT Geiger Counter - ESPHome - Home Assistant

I'm genuinely impressed by this Geiger counter!
The sensor setup is seamless, and it integrates into Home Assistant without any hassle. The radiation readings are accurate for general monitoring, and having extra sensors (temperature, pressure, humidity, gas) in one package is a big bonus.
I appreciate the open-source nature of this project, firmware and 3D designs are available, which makes it fun to tinker with. Also: USB-C ❤️
Highly recommended for anyone into environmental sensing or just wanting a cool IoT gadget!