Ok, I’ve chosen a new type of keypad that is probably more suitable as it is rigid and can be incorporated in the device itself. I had tried this keypad before but could not get it to work properly, but now, using interrupts that allow me to detect rising and falling voltages, it works well. This image also shows how everything is connected up to the Teensy. I’ve build the rechargeable battery module so we’re ready to go from an electronics standpoint. Now, I just have to redesign the box it all goes into…
