As you can see, it has a solar panel that folds down flat to the back for ease of portability, and a usb cable to charge it from a computer or other usb power source when significant light is not present. The one problem is that if it is receiving power from the solar panel and the computer at the same time, it will cause the charging circuit to send power through the usb cable, and mess with your computer. This is due to the very cheap charging circuit used to keep cost down, so if you wanted to avoid that problem, cover the solar panel while usb charging. The front device slot is sized to fit anything up to a motorola RAZR maxx width wize
Now keep in mind, the battery that is used is close to the capacity and mA rate of an Ipad, therefore as mentioned earlier, this device will keep playing, and playing, and playing. I've had to recharge mine maybe 2 times a month in direct sunlight. Besides that though, i keep it on my desk in my dorm and use it often. Another thing to remember is that THIS WILL NEVER RUN OUT OF ENERGY. Hence the solar panel. Gotta love sustainable energy dontcha ? :)
I guess the one downside to this whole project is the cost. To build myself one of these it set me back $160-170 for components and another $15-20 for the actual plastic for the 3D printed components. And keep in mind, you'll have to purchase a separate auxiliary cable to plug into the front
This was a concept thunk up and created with a 3D printer by Rob Martin at Illinois State University, so all credit goes to him. If this instructable wins any awards, all prizes and credit will go to Rob Martin. Rob told me that i had permission to enter it in online competitions such as this one under my own name because he didnt have the time to do it himself. He led a small class of around 10 students in the renewable energy program at ISU, including myself, on how to print, and assemble the components correctly.
The photos of the blue, red, and yellow stereo components are the bones of my own stereo! Also you can see the mp3 circuit fully assembled. Sadly, i made this a while ago and didn't think to take pictures of all of the components or the finished product, which is sitting at home while I'm at college...so the picture of the finished one is the green unit made by rob himself.
Here is the website where Rob posted his project: http://www.thingiverse.com/thing:42586
Remember I am simply making an instructable for someone else's idea. Again I have been given full permissions for this as long as all credit and awards (if we win) go to Rob Martin.