This is a clock board designed to mate with the 6-segment or 7-segment display boards that I previously published. It interfaces to a DS3231 module for accurate timekeeping. The design is conventional. As there is plenty of room on the board, it supports options, annotated in the schematic. That's why it's not fully populated. The firmware is at Github, see the links.
I managed to get a professional STC89C52 MCU to pose for this picture instead of the WFH model shown in the virtual 3D rendering. Also the PCB insisted on coming dressed in blue soldermask so I had to indulge it a bit. 🤣
Time passes. I was forced to take a many-month break due to renovations on my home. Finally I got around to installing the missing connector and plugging in a test 4 digit display board. You can see the result in the gallery. Sorry for the fisheye distortion, I used my phone camera. I really need to set up a proper photographing environment for my projects. You can see the RTC in one photo. The firmware was tweaked a little, you can see the details in the Github repo but no substantial changes as testing had already been done with the QX-mini51 development board. Now I can finally mark this project completed. I'll probably couple it to the 6-segment display that I built in #6 segments suffice and give it to a friend as a novel memento.
I've added a couple of photos to the gallery of the clock board piggybacked onto the 6-segment display. You may notice that the 0 is not the same as in my project #6 segments suffice . I'm experimenting with using the upper loop as a 0, but it's compromised by the gap in the middle most clearly exhibited by the 5.