Hacking DSP-420 LCD displays

April 25, 2010

I recently found a bunch of DSP-420 LCD displays, like the ones that you see on POS terminals in grocery stores. After a fruitless battle with the proprietary protocol of an LED wallboard (that I also found at work :) ), it was good to find so much protocol documentation on these little displays. I had it up and running within a few hours, displaying the artist, title and track length from shell.fm. (Started a github repo for the code too.)

My friend suggested hacking the USB -> Serial adapter I had, and using 5v from the USB port to power the device itself. It works brilliantly. With the same friend, we’re also in the process of designing and etching a PCB for an 8 channel relay board, to be attached to my K8055, I’ll post a bit about that next..