who doesn’t like a great surplus store? [Tyler Bletsch] just completed up this awesome clock hack by re-purposing a scrapped medical circuit board.
Ax-Man Surplus in Minneapolis has all kinds of goodies as well as it’s been around a long time (here’s a hack from the ’90s that source from the store). one day while digging with their inventory, [Tyler] discovered a lot of scrap circuit boards with 7-segment displays. At $2 a pop, he made a decision to danger it to tinker with.
He swiftly identified the primary chip on the board to be a typical LED motorist (MAX7221) as well as began reverse engineering the board by tracing the circuit. He really has a dazzling guide on his web site about how to make circuit tracing method easier. From there it was just a matter of loading a MAX7221 library onto a ATtiny44, adding a 16MHz crystal, as well as considering that there’s an additional 2 digits offered on the display… a temperature sensor too!
It’s a excellent little hack, as well as as it turned out, there wasn’t anything wrong with the boards, except for a minor typo in the company’s name. Hooray for reusing scrapped parts!