Page 1 of 1

Getting Started with Matrix LED Displays...

Posted: Mon Apr 29, 2013 11:45 pm
by DavidMil
Mr. Henry suggested a CD4017, but I used three 74LS154's (4 to 16 demultiplexer) when I built a scrolling sign about 12 years ago. It was something I had always wanted to do. And yes; I actually soldered 294 (7 x 42 rows) individual LED's, 42 2N2222 transistors, 42 3K resistors, seven 74LS04 Hex Inverters and three 74LS154's and a few other components to protect the Mirco processor, on a perf board (the biggest one I could find).
I used a Parallax BS2px24. It worked fine. I could display or scroll messages across the board from either side or top to bottom. Of course I had to figure all the ASCI characters in hex one line at a time, but it kept me busy for a few months playing with it. Needless to say no one was as impressed or as excited as me that it worked! It would have been much easier with LED matrix displays. Nice article!