I been considering build an table top arcade cabinet for a while. Since I’ve had some spare time lately I decided to start a project to build one. I wanted to use as much stuff that I had around to keep the cost down so I decided to use a Raspberry Pi for running Mame, an old VGA monitor, some spare particle board and an old ATX power supply. I’m also keen to have the potential to change to a JAMMA board or old PC in the future.
For the cabinet I looked at a few internet designs (weeCade and some others) but decided in the end to just create a rough sketch in 123D and build based around the size of the monitor I had.
The next thing to do was to order in some arcade controls. I used http://www.austinamusements.com.au and ordered their $30 bundle and a $17 coin mech. I fitted a one player control board to just get things up and running. I also needed to get a HDMI/VGA converter which came from ebay. For audio I’ve used a cheap 1W amplifier kit and two 1W speakers.
Time to wire the Pi up with the monitor and audio and have a quick test. For the test I have not wired up the control surface so wss using a keyboard. The Cameleon Pi distro has Mame installed so it was pretty easy to get up and running. I had to changed the HDMI mode to 2 in the /boot/config.txt which fixed the audio out (from the HDMI adaptor) and as I was change the config I also increased the over clock to 1Ghz. At this point everything seems to be working apart from the controls!
The test control surface is built but not interfaced to the Pi. I’ve had a few ideas on ways to do this:-
- Buy a USB keyboard control surface interface. There is some boards available for this purpose or the other option was to try and make one from an old donor keyboard. I don’t have a donor keyboard and I didn’t want to buy the convertor.
- Interface the controls directly to the GPIO on the PI. This was my original though cut to it being reasonably simple however there is a limited number of pins. For a 2 player, 3 Button controller with P1/P2 buttons and coin mech I’de need 17 inputs.
- Using an IO expander IC on SPI. This wasn’t a bad idea but I need to order in some expander IC’s…
- Use an Arduino to control get the inputs and convert to SPI. This is option I’m going to go with as I have all the parts. I am short one input as I am using an UNO so will put the coin mech either on a Pi GPIO or make it use the same as P1/P2 pressed together which would also allow adding credits without using coins an alternative would be to use multiple inputs on one analogue input using a resistor network. Using the Arduino also has the advantage of allowing extra features easily (such as auto fire) and has analogue inputs if required.
As I chosen to run with the Arduino solution I’m currently doing a little research on how to get SPI working between Pi/Arduino which I’ll post on once working!
I’m also looking to get a backing printed for the control surface which I will then cover with some clear plastic sheet.