I am trying to fix a friend’s 8-player game show buzzer. I created a “breadboard arduino” and soldered everything to a strip board. I am supplying power via a 9V 0.5A wall wart through a 5V voltage regulator. After plugging it in it’s supposed to flash the 8 LEDs and play a short tune. Then it goes to the main loop. I adapted the tutorial showing how to do several things at once without delay. This assembles a random byte that is sent to 74HC595 shift register controlling the 8 LEDs in a random twinkle pattern. Every lap through the loop it evaluates the twinkle pattern, shifts out the byte and polls a 74HC165 to check if one of the 8 player buttons has been pressed. If anything other than 0x00 is on the '165, it sends that byte to the '595 plays a few notes and holds waiting for a HIGH input from the game reset button (do while input LOW loop). After game reset, it goes back to the twinkle '595/poll '165 loop.
What actually happens is I plug it in, the opening tune faintly plays, the LEDs flash once and then nothing. Dead. I’ve attached the sketch and “As-Built” schematic. Hopefully someone smarter than I can identify where I went wrong. I tried inserting the code between tags but it puts me over the 9000 character limit. I probably could have condensed the twinkle code into something a little more compact but I didn’t anticipate these problems. Lessons learned for next time.
Edna Runner.pdf (63.3 KB)
Runner_Elegant.ino (10.2 KB)