As promised, I've put the keyboard scanning code covered in the last three logs online and you can download it from this page: https://dboucher.org.uk/keyboard.
Keyboard with Arduino UNO and paper pin insulator.
This version is set up for Arduino but it should work on anything Arduino compatible with enough GPIO pins. I've used it on a Teensy LC for example.
There is a README with more info in the download. I hope you find it useful.