I have put this project together, and as you may see I have a half size pcb board strapped to a full sized bread board, and I’ve soldered a few male header pins, resistors and buttons to the pcb board.
I have checked that power is getting to each device which is attached , and there isi full continuity between various points on pcb board and breadboard.
The DS3107RTC is working and returns an address when I used the I2C scanner, and the display lights up when a 5volt 2.5 amp power supply is connected.
After I uploaded the sketch and powered up, only the display came on but no sketch running.
The code and a picture of the setup attached
MAX7219_RTC_dht11.ino (12.6 KB)