So what to do when a CD player stops working? Turn it in a media player with Internet radio capibilities, mantaining total functionality of the buttons of the panel. A first idea was to use an ASUS router as the media server hardware as created byMightyOhm. But now with the advent of the Raspberry Pi, this is a much nicer hardware that allows us more flexibility.
On this first part I'll show how I created an interface board for the display and buttons of the CD player. I have chosen an controller an ATiny2313. It's cheap, has a good number of IOs and has USART. The player has 8 buttons, one led and a VFD. Since the original VFD was too specific I needed something more flexible.I didn't want to connect every button to an input of the MCU, since I didn't need symultaneous button presses. So I used a voltage divider with a stack of resistors. All 8 resistors have the same value, 10KΩ