Tuesday, November 11, 2008
PIC Based Digital Clock
A little time ago my clock died on me, I thought well why shouldn’t I just build one myself? So that is what I did. This clock is based on two PIC16F628 chips, I know that it could easily be done with a smaller PIC but this was the only type I had lying around when I built it. One of the PICs does nothing more than creating a 10Hz clock. The other PIC drives the 15 7 segment displays (which ironically have 8 segments including the dot) and the counting. To save some IO lines the almost 128 LEDs are arranged in a matrix, and to save even more these lines are controlled by three 74HC595 shift registers. This way it is possible to control all segments with only three IO lines.
The clock does take care of the different lengths of the months and leap years, just when I thought I had everything….. daylight saving…… well maybe something i’ll fix later on then…..