Coining Up the Bellco using an Arduino Nano

[atlanticom]

While I was repairing a broken Bellco Double Chance machine I purchased, I needed a way to coin up even though the photo interrupters (PI) in the coin slot were defective. To do so, I used an Arduino Nano micro-controller to simulate the pulses the defective PIs should have been sending. Once I worked out the required timing I was able to continue my repairs while awaiting replacement parts. Once the defective PIs were replaced I found that I missed having the ability to coin up the machine quickly (and without robbing from the hopper.) So once I got the machine fully working, I decided to update my Arduino Nano solution and add a 'quick coin up' feature to the machine permanently - while still maintaining the ability to coin up using tokens as well.

During the repair process, I learned a lot about the stop button circuitry while helping another Pachitalk member troubleshoot an issue they were having. With this knowledge, I decided to improve on my original coin up design by intercepting signals from the stop buttons and using that information to trigger the Nano to simulate coins through the slot. And since I had the available pins, I added the ability to trigger a soft reset of my machine as well.

So how does it work? I ran the signal wire from each stop button as well as the two signal wires from the coin slot PIs into the Nano as inputs. That way the Nano can sense what the player is doing. The Nano also has outputs going to the each of the pins on the machine circuit board (where the original signal wires were located.) That way the Nano can pretend to be the button or coin signals. Now that the Nano is essentially inserted between the button & coin inputs and outputs, it was a simple matter of programming the Nano to mirror each of it's input signals with the associated output signals.

Well so far, the machine works as it always did. Buttons stop the reels and coins add credits. But here's where the magic happens. The program can also check to see if more than one button is press - and for how long. I decided that pressing buttons 2 & 3 together for over a second should trigger the coin up process (sending the correctly timed pulses to the coin slot outputs.) I then decided that pressing all three buttons for over a second should send the appropriate output to the soft reset line (I connected it to the Nano as well.)

The result was a complete success! I can play normally, coin up with tokens, coin up by pressing buttons 2&3, and perform a soft reset without needing to open the cabinet.

I'll attach a couple pictures to give an idea of what the install looks like on my machine. I've also shared the code I used to program the arduino nano. Here's the link: https://create.arduino.cc/editor/atl...f707db/preview

If anyone has questions about aspects of the project, I'll gladly respond.

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