I got this display  by mistake. I was buying a bunch of the MAX7219 displays and mistakenly added this one to the cart too.

MAX7219 have internal multiplexing these 74HC595 ones need external multiplexing code. I’m no stranger to that since I have done it for Futaba displays. The schematic looks simple enough…

At least it was only $2 lost. Returning it would cost more so I tried to make it work. I checked the Arduino forum and all the posted solutions did not work. I cobbled this test program together from all those posts and revised the display mapping to make it work.

I probably wont use it since it takes too much processing power to update it but it does work. I’ll leave it in the PDL for someone else to play with.

Here’s the code:


Now if someone wants to make an interrupt driven library that would be nice…. Just not me….

74HC595 Shift Register Arduino Display