Vermes
Advanced Member level 4
This LED clock was based on microcontrollers PIC16F84A and displays HD1131. The program was written in Assembler. The project was made on universal board. PIC16F84A with clock quartz 32768 kHz through decoder CD4543BE controls the LED displays, which operate in multiplexed mode. Time is set by two microswitches. The program was written in a way that a single pressing the microswitch jumps by one hour or minute, and longer pressing it accelerates setting the time.
In the back there is a glued clear housing made of plexiglass (one of the assumptions was that the clock was to have visible electronics components). Scheme and program can be found at the original thread.
It is difficult to solder on such a small board, so it would be better to design and digest a board.
Scheme:
Elements needed:
- programmer for PIC microcontrollers, for example JDM
- PIC16F84A
- CD4543BE
- 2 bases for those systems
- 4 displays HD1131 or similar with a common anode
- 40 PIN base for the displays
- quartz 32758 kHz
- 2 capacitors 27pF
- resistor 22 kOhm
- 2 resistors 3,3 kOhm
- 7 resistors 330 Ohm
- 4 resistors 3,3 kOhm
- resistor 1,2 kOhm
- 4 transistors BC327 or similar of type PNP
- 2 microswitches
- universal board (Cyfronika UM-0)
Link to original thread (useful attachment) – Zegarek LED pic 16F84A na płytce uniwersalnej
