I started some testing of various displays for a project I have in mind for a control panel. This time around was testing some 14 segment displays. I did some reading and it seems it's possible to drive this with MAX7221 chips.
Indeed this application note from maxxim integrated shows exactly that.
I also saw this guys page talking about it as well.
I didn't have any DIP packaged MAX7221, only a single MAX7219. However I had a bunch of surface mount MAX7221. Rather than order some more DIP packages and breadboarding it (which would be a pain anyway due to the mass of connections needed) I decided to just go ahead and make a board for the project.
The schematic pretty much followed the application note directly.
Top copper:
Bottom copper:
And here we have it all soldered up.
Top:
Bottom:
After some initial testing the display seemed very flakey. The display "worked" to a degree but there seemed to be timing issues and thus some software testing and tweaks needed. It also might simply be due to the capacitors I used as I did some further reading about how others had implemented this design. Further testing required!
It might also be worthwhile to do this with shift registers instead oif the MAX7221's. Either way I'll update this once I figure out more :)