Build Your Own WiFi-Equipped and Feature-Packed Geiger Counter

Ambient radiation is naturally surrounding you at all times, but it’s almost never dangerous. The radiation levels are too low to be a problem. But there are areas where it is higher than normal and potentially-dangerous. Those areas are almost always clearly marked by the country’s government, but it can be fun to see if you can find “hot spots.” To do that, you’ll need a way to measure radiation. Instructables user prabhat_ has a tutorial explaining how to build one of the most feature-packed Geiger counters we’ve ever seen.

This is actually a multi-function device that combines a Geiger counter, dosimeter, and radiation monitoring station. Geiger counters show the current radiation levels over a revolving amount of time—usually by chirping whenever a “pulse” is detected, while dosimeters show the accumulation of radiation over a duration of exposure. This device contains both functions, and also has built-in WiFi so you can leave it somewhere to monitor radiation over a long period of time while sending the recorded data out over the internet. The device has an integrated touchscreen display with a very nice-looking GUI (Graphical User Interface) that you can use to navigate through the various functions and to change settings.

This device uses a Wemos D1 Mini ESP8266 development board, which connects to custom PCB. A readily-available SBM-20 Geiger tube is used to detect radiation, and it costs just a few dollars online. The display is a 2.8” SPI touchscreen, and power is provided by a LiPo battery through a 3.7V LiPo charger and protection board. Assembling the electronics will require SMD soldering, but the SMD components aren’t too small. The enclosure is 3D-printable, and is designed to use heat set threaded inserts. The custom software can be uploaded using the Arduino IDE. The total cost to build this Geiger counter should be less than $50, and it offers more features and customizability than the cheap Geiger counters on the market today.