I had this handy board based on the Cypress EZ-USB FX2LP chip. I wanter to read the software that was driving the radio for a 2001 Benz S-Class, so I put this cobbled-up EEPROM reader.
I also build an 8051 CPU emulator to see what the software was doing. Didn’t get much info from it apart from the chip init sequence, because the emulated radio was trying to talk to the security CPU on the front panel and shutting down.
This is a small experimental board I built to connect the optical adapter from a CD-changer to a PC so I can control the D2B protocol chip via i2c.
The board had a flat cable connector to the CD- changer board, a small A2D converter with aux-in, some pins for the I2C protocol and a LDO.
Interesting accident I had was that I used solder flux which converted to zinc-oxide over time and shorted some of the PCB traces. It took me quite a while to figure out why the thing would just stop working.