Burping Piggybank

Feed this piggybank with a coin and it will thank you with a nice burp. The heart of this project is PIC12F683 microcontroller (by Microchip). Sound data is stored in its 2K flash program memory. Sound data bytes are read from memory and are shifted left 8 times to one output pin at 23uS intervals. A simple RC lowpass filter reconstructs the original audio signal.

I built this project in a whey protein (1 Kg) container. PC board, speaker and coin-sensing switch are mounted on the lid.

Download link for PCB, HEX code ASM code & pig eyes-nose-ears (sticker PDF)

Switch is made with copper /aluminum /tin foil.

Battery (3 AAA or 3AA cells) are lodged in a separate plastic box