When I first read about the raspberry pi, I was fascinated with the possiblities and began thinking of a good first project. I had read several stories about people connecting vintage jukebox wallboxes to a pi in order to select computer streamed music, but I wanted to do just the opposite. I have a 1959 Seeburg 222 jukebox in my basement gameroom, and I wanted to remotely select songs just like would be done with a wallbox. I have the basic function working well, although I may still add some features to the user interface.
The way wallboxes transmit song requests to the main jukebox is through a series of pulses, that are then decoded by a stepper unit in the main jukebox. Seeburg jukeboxes are nice for this project since most of them come with the stepper unit built in, where other brands sometimes needed steppers added seperately.
In order to generate the proper pulses, I am using a Sainsmart 2 channel relay board directly attached to the GPIO on my pi, driven by a small python program. Since the relay board interprets GPIO low as activating the relay in my program when I initialize the gpio pin it is immedately set to high and drop it to low to send a pulse. I also had to experiment with different length of pulses and pauses go get the stepper to accurately select the correct song. The simple user interface to the program is created using jquery mobile intended to be used from a smartphone or ipad. I am using bottle to use as the web framework as it set up quickly and provides all the features I needed.
I will post a video of it working soon, and a link to source code in case anyone is interested. Comments and questions welcomed.