After the dissolution of the Soviet Union, the world has enjoyed a period relatively free from the fear of military nuclear weapon use. Unfortunately, between the slow propogation of these weapons along with political bluster, this once again seems like a real possibility. While YouTuber Andreas Spiess hopes that he's built an extremely unnecessary device, his connected Geiger counter will allow you to monitor radiation levels for around $50.
The DIY Geiger counter has long-term monitoring capabilities using ThingSpeak and IFTTT. (📷: Andreas Spiess)
The heart of his device is a counter purchased from a Chinese supplier, which ticks usefully via a built-in speaker. To increase the device's cusefulness, an ESP32 module is added with a display that shows radiation ticks per minute. Along with local display, the module connects to the Internet, turning this information into an alarm via ThingSpeak and IFTTT. If radiation levels spike, you can duck into a fallout shelter or other protective bunker, warning others to follow you as their "nerd hero."
While hopefully these devices will never be needed, it's interesting to see Spiess' testing at 4:20, showing the difference between the first floor and basement of his house. It would be interesting to see a network of similar devices deployed in order to determine regional differences in radioactivity depending on the time or weather.