Overhauling a Slot Machine

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Ah... Not really. But this project is still interesting. I acquired a slot machine over the summer of 2016 and naturally wanted to mess with it. This slot machine is called a “Pachislo machine” and is found in Japanese game parlors.


First step: figure out what all those Japanese symbols are saying. I ran it through Google Translate and learned what all the buttons and gizmos do. You can change the sound level, reset the machine, change the odds of winning, etc. Here’s the inside:


The machine makes typical noises when you put coins in and play the game, but I wanted to change it up and play my own noises. I disconnected the wires feeding into the speakers and instead plugged them into an Arduino micro-controller. After some fiddling around, I found the normal voltage levels sent through the wires when a sound is supposed to play.

Then an Arduino program sends its own sequence of frequencies to the speakers once it detects that a sound is supposed to be playing. Now the slot machine will randomly play the McDonald’s jingle, a fiddle jig, or that catchy Chinese tune whenever a sound is supposed to happen. The Arduino script is linked here.