Making cool projects on the Raspberry Pi is more often than not the whole point of having one. The single-board computer's 40 GPIO pins make it possible to attach a seemingly endless selection of external sensors, buttons and more but maker Mcllrn decided this was no longer necessary. Using nothing more than the CPU by itself, Mcllrn has managed to turn the processor into a functioning button you can use for input in any Python program.
Add this to our list of things you can do with a Raspberry Pi that you probably should not do. In the spirit of pushing the Pi to its limits, we had to feature this project as it’s one of the most clever uses of the CPU we’ve seen so far.
The button “presses” are registered by constantly monitoring the temperature of the CPU. When Mcllrn touches the processor with a bare finger, the temperature lowers. This temperature change is enough to detect and register a specific response. A simple Python script demonstrates the input recognition in the demo video shared by Mcllrn.
Some of the best Raspberry Pi projects are the ones you can recreate at home but you may want to slow down before you begin poking your processor. It’s definitely impressive that something like the CPU can be used in such a way that deviates so far from its original purpose. However, this setup is far from optimal in a practical setting. Continuous use could damage the processor, especially when factoring in hazards like static.
Check out the original Reddit thread to get a closer look at this awesome CPU button project and see it in action.