I pulled this coin mech from an Asteroids cabinet I converted to Mame.

it looks daunting with all these wires but its really simple.

Most of that wiring is lighting and tamper switches. there are two micro-switches that actually detect the coins. there are also two counters that keep track of how many coins have been collected. About 69,000 Quarters totaling over $17,000  have been through here…..

An Arduino Leonardo will make this Mame compatible…

I may just save this one as a spare for my Techmo Cabinet Rebuild and build the Arduino controller with these generic quarter mech’s. They will work nice in a DWjukebox project too.

Here’s all there is to the circuit. A Leonardo or Micro and a 4.7K pullup resistor. The computer sees it as  a USB keyboard and every time a quarter is detected it sends the keycode for the insert key which , by default in DWJukebox, is the quarter signal.

The code is not much harder…..

Here’s the sketch if you want to try it….


2 thoughts on “USB Coin Drop Mech for Ardiuno”
  1. Hi,

    I am putting together a mame cabinet, but am pretty tech-stupid. I would like to put in a coin mechanism like you have here but have no idea what the Arduino Leonardo you mentioned is. I found one on Amazon but it looks a lot more complicated than the one you have pictured. Do you think you could post links to where I can find the device you used as well as step by step instructions? I’ve been searching the web, but so far this page is the only one I have found.

    Thank you, in advance,

    Bill Lee

    1. The Arduino in my post was the Micro. You probably saw the full size Leonardo. If you are new to this the Arduino Leonardo is probably easier to start with. You will need a 1K to 10K resistor for each switch you want to have. Each coin drop chute has a switch. If your building a cabinet you may want to use the extra power of the Arduino to run a bunch of other switches.

      Here’s one I built a while ago:


      Only the top 6 switches apply to this topic.

      This panel has 4 different controllers. Each joystick, with its 10 buttons, is on its own board and appears as a standard joystick under windows. The trackball and its 3 buttons has its own controller and appears as a standard mouse.

      The top 6 buttons are connected to a board like the Leonardo and it appears as a standard keyboard under windows. Hitting the 1 2 3 or 4 player buttons is just the same as hitting 1 2 3 or 4 on a keyboard.

      Its just a couple of more lines of code for each key you want to add. Getting the first one running may be a bit of work. The arduino needs to be programmed. That means installing an Integrated Development Environment (IDE) on your computer, adding com port drivers, and uploading the sketch to the Arduino. Its not hard at all just a little time is needed.

      It may be best to contact a local maker group or ham radio club. You’ll find people with a lot of Arduino experience who would love to help design a Mame Keyboard

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