I did something similar a while ago, made a 9-key Macropad using a Teensy. I've been wanting to try making a new one with BLE support and an integrated battery

I did something similar a while ago, made a 9-key Macropad using a Teensy. I've been wanting to try making a new one with BLE support and an integrated battery for wireless. Using Home Assistant is quite a good application for a device like this!