This project took longer than I expected, partly because I was trying a few different ways that would allow us to unlock the office door. One such attempt was using a Lockitron, but that would have meant that we couldn't unlock the door with a key anymore and that was just not going to work.

One enhancement that I wanted to add was support for encrypted key cards, such as Oyster, Apple/Android Pay and contact less bank cards. This required removing some checks from the Adafruit PN532 library. My version ignores invalid check sums instead of crashing with an error (which happens in the original library when reading these cards).

I plan to add a Flask server to the script, which can be exposed over a public device URL and would provide an API endpoint to open the door remotely. This can be combined with our Hubot such that the door could be opened by asking it on our company chat: hubot open the office (possibly adding some magic keywords for security, such as please - or something more secret)

I might also add a front-end that shows who is in the office, based on their card login - although this may be slightly Orwellian.