08/14/2021 at 13:33 •
-It just works
- RC filter for the buttons does not allow programming the PIC once the PCB is fully assembled.
- Improve ICSP Port.
- Increase Display current for better brightness.
08/14/2021 at 13:31 •
The schematic is showed next:
As you can see, the design is pretty forward: The pic18LF14k50 drives some NPN transistors, which allow the display to light. Same for the buzzer.
As you may know, the display has the four displays in parallel, so we will need to have a high frequency blink in order to "trick" the human eye to see them all light at the same time.
For the buttons, a RC filter made of 10K resistor and 100nF will filter any bouncing effect, having a great counting experience.
08/14/2021 at 13:22 •
Components are placed, trying to use the fewer space possible in a 2-layer PCB:
Then, exporting the files from Kicad to FreeRouting tool, the layor is made:
Finally, the PCB is filled with GND copper planes, and imported to KICAD again:
And now everything is ready for the PCB manufacturer