So, want build ugly real time clock (RTC)? ;)
This real time clock is build using PIC16F84 (16C84) CPU for control and display and Dallas DS12887A RTC for clock.
In fact this clock is testing prototype for more complicated clock design. I build this device for testing my programs on PIC microcontroller.
Device list:
PIC16F84A
DS12887A or analog
~4MHz quarz crystal
7 seg LED indicator (used old soviet ALC324 from some device I found in garbage pile)
K155ID4 (74X138)
4 diodes
few resistors
few switches
4 transistors (generic)
There is no real schematics, as device was constructed on-the-fly. But I reverse engineered some schematics. There maybe errors, but if you have some experience, you may fix them. Schematics:Huge for printing and Smaller for viewing. (schematics is for reference only.)
Software: Same as the hardware. Maybe errors, maybe useless things, but it works. Dowload it here: din9.asm. Hoow to use?The device is useless, unless you modify code. There are two buttons. One to increase, other to decrease RTC memory address. With small software modification you can make it real clock. But it is prototype for more complex device.
