Video
I built this project in a whey protein container (1Kg)
Schematic
Circuit operation details
Coin actuated switch
Contact plates are made of copper, aluminum or tin foil.
Switch mounting
Contact plates are glued to the bottom of the lid
Lid preparation
Cut holes for coin slot & speaker
Mounting the PC-Board & speaker
PC-Board
DOWNLOAD LINK to PCB, HEX - ASM codes and stickers PDF
This is a great example of the limitations a toy designer has to work within. Thanks for sharing.