One of my friends in college gave me a PIC16C745 chip today that is coincidently flashed with the same firmware as the chip in the K8055 card (i know ive swapped them round and tested it =)) so the chip definately works.
I then decided i was going to make my own interface card based on the chip and got out the schematics of the board and started putting it together on my breadboard. My problem is this, when i connect it to my computer the LED (LD8) flashes twice then stays lit on the 3rd flash. I’ve swapped the chip on my breadboard for the chip out of my interface card and still the same problem.
I drew a quick circuit diagram for you to look at.
Some ideas i had about why it might not be working:
- What happens if you use a crystal that isnt 6Mhz (10Mhz is what im using) i know the chip can work up to 20Mhz
- What happens if C6 isnt 220nf (im using 4x 26nf in parrellel = 224nf)