Well, this is only the second project/program i've ever written for the PIC, and i'm not a very good programmer. The first was a simple stepper motor driver. I didn't try to minimize the code, but i know i can. This was just a simple program (written in PICBASIC) to learn how the LED matrix works. how i did it: the matrix is 5 common cathodes (5 columns), so i light the proper LEDs one column at a time, pause for 2ms, and go onto the next column, and cycle about 10 times. i did it late one night, but looking at my code the next day, i see many ways i can shorten it. I'm a college student interested in microcontrollers, but i haven't gotten that far in my studies yet, so i'm learning on my own time during summer. If anyone can post a small example of how i can minimize the byte count per letter, i would greatly appreciate it. Thanks, Scott On 8/20/05, William Chops Westfield wrote: > On Aug 19, 2005, at 7:03 PM, scott larson wrote: > > > I just made a 5x7 LED matrix display driver using a PIC16F84A, but i > > can't fit each letter of the alphabet into the chip due to the small > > memory... > > Really? 5 bytes per character, right? 40 characters gives you > most of what you need; add 26 if you want lower case. 96 > or so is all of printable ascii, and should fit in just a bit > over half the available memory (not that upgrading beyond an 84a > isn't a good idea anyway...) > > Old computers used to use "radix 40" for symbols and things, > since you could get 6 characters in 32 bits (now you know where > 6-character filenames came from!) > > I have a project in mind to drive some dot-matrix LED displays > from a PIC; I was hoping I'd get away with a pretty tiny PIC; > did you find something I'm missing? > > BillW > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- Scott Larson 3201 S. State. St. box 2561 Chicago, Il, 60616 619-400-9775 http://goldscott.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist