For Tom Shaffner, it was a cold winter, and due to working from home with 24-hour heating, he needed to check whether the insulation of his house had improved.
Tom has a cooling fan device – camera in the lower right corner
An affordable solution
His initial idea was to buy an infrared thermal imager, but he found the prices were not as cheap as he hoped, ranging from thousands of dollars to hundreds of dollars, but he could rent one for 24 hours for $50 from the hardware store.
When he saw the $50, he realized he could buy a $60 (£54) MLX90640 thermal imager from Pimoroni and connect it to a Raspberry Pi 4, which was completely affordable.
A joint open source effort
After Tom’s hardware arrived, he took the opportunity to combine several other projects into a unified Python library that could be downloaded via pip and run locally and as a web server.
The heat map on the right shows that the computer screen is the hottest part of the room
Tom also published everything on GitHub, for individuals interested in further development.
Quality images
However, the biggest question was whether the image quality met practical needs. A few years ago, the cheapest infrared thermal imagers only had an 8×8 resolution – barely acceptable.The magic of the MLX90640 thermal imager is that, at the same price, the resolution jumps to 24×32, providing 768 different temperature readings per frame.
The thermal image shows – the ceiling light generates heat, which is lost through the window
By adding some interpolation and image magnification, the final result can do the job well. Streaming video over the local wireless network, you can hold the camera in one hand and use your phone as a screen in the other.
Bonus security feature
Bonus: If you keep the web server running after completing the thermal imaging, you will have an affordable infrared security camera.