I was interested in how the board in my new K40 laser cutter was laid out and functioned.
A mystery chip is always a puzzle that can be fun to crack :)
Very simple design. Although they could have used more of the error checking on the CH314A. Best discovery is the possibility of there being a uart port to exploit :D Sadly all but 1 of the pins on the mystery chip are used and nothing traces out to anything useable for extra end stop switches.