Quote Originally Posted by Dazheng View Post
Greetings Trent,
I have some question, is it possible to extend it for more characters, as of now it has seven character i want to extend it for more characters. can you please guide or give some example on how to do it. Thanks in advance....
I don't recommend cascading anymore sections. The duty cycle is extremely low as it is. About 2.5% for each column. What this all means is that the LEDs won't be bright enough if more columns are added.

If you want to build a really huge display with a 100 or so columns, your best bet would be to use a few PIC16f877's. Break it into 4 sections - 25 columns for ea controller. The display will be nice & bright this way. Big job!

The hardest part will be in the software, making sure that ea section is properly synchronized with minimal latency. Shuffling data between ea section. On second thought - it's a masive job to do properly.