We have such an abundance of computing power available to us these days that we can afford to allow for some inefficiency in how we use it. We don’t need to come up with complex and cryptic algorithms, for instance, to shave a few clock cycles or bytes of memory off of a program anymore. And as Jean-Luc Aufranc just demonstrated, many of us can even spare an entire computer to act as a Bluetooth keyboard for interacting with another computer.
Yes, it is ridiculous. I mean, it’s not like keyboards are expensive or in short supply. But it did get Aufranc out of a tough bind recently. With work piling up, lots of computers to work at, and a shortage of keyboards with which to do that work, Aufranc turned to a newly-acquired Raspberry Pi 500+. Sure, this computer alone could have been used to do much of the work, but that would involve moving lots of data and installing tons of apps.
HID device, huh? (📷: Jean-Luc Aufranc)
So rather than doing any of that, Aufranc simply hacked away at the Pi 500+ to make it present itself as a Bluetooth HID device to other machines. And as a bonus, it comes equipped with a very nice mechanical keyboard.
This was all made possible with the help of a C and Python Bluetooth interface called btferret that has been developed for Raspberry Pis. After compiling and executing a small program, the Pi 500+ will present itself to other computers as a Bluetooth keyboard. Once connected, it will transmit key presses just as you would expect any other keyboard to.
However, this method definitely falls into the category of dirty hacks. It’ll get you by in a pinch, but you’re going to find plenty to annoy you as well. Some of the keys don’t work, and if the Pi doesn’t stay on the desktop, nothing at all will work. Also, forget about using the ESC key. That will terminate the program and make your keyboard vanish.
If you do find yourself in a similar pinch, read up on the project write-up for more details. The same technique should also work with a Pi 400 or Pi 500.
