Panasonic car stereo CD Changer Emulator circuit

News

• 19 July 2018 - Stocks have run out
  Hi all,
  I've been making these devices for 18 years now and though I'm happy to hear that some still have these radios, I've yet to find motivation to make another batch. For this reason, I'm removing the 'Buy Now' button from this page. If you're still interested in a device, send me an email and I'll put you on a (non-binding) interest list. Thanks!
• 29 October 2017 - Still active
  No news is good news! I still make these units and I ship them whenever I receive an order. This message is added to let you know that despite little activity, everything's still as it used to be.
• 12 March 2012 - CDCEmu v5 is here
  A new version of the popular CD Changer emulator is here! The reworked version has streamlined the manufacturing process but requires more expensive tools (which equals to a higher initial cost of manufacturing). The new version has all circuits embedded in the contact itself, and has thus eliminated the short cable from the contact to the circuit board.

Background

I have a CQ-DFX301N car stereo in my car, and I lacked the support for reading CD-RW discs and MP3, and it didn't have an auxillary input. What it did have was an input for a Panasonic made CD changer, so I figured I could do something with that.

I found a DIN 8C port marked CDC on the back side of my head unit. After some research, I found out that the port is a communications port for a Panasonic made CD Changer. I figured that this port must enable the (Auxiliary/AUX) RCA inputs marked CD-C-IN, and so the CDCEmu unit was constructed.

I often get the question if it's not just a question of shorting two pins. The answer is NO - never try it, it will not work! The radio must receive a valid signal to enable the CDC inputs. If it does not, the CDC input is disabled within a second.

Compatibility / Satisfaction guarantee

While the emulator seem to work with almost all units having the 8-pin DIN-style connector on the back side, there's at least one model that is not compatible: CQ-C3301U. If you want to try the emulator with your unit, just place an order and try it out! If it does not work, send the emulator back and have your purchase is refunded!

Pictures

Shot of the CDCEmu v4 (development version) and CQ-DFX301N showing test data


Shot of the CDCEmu v4 and CQ-DFX301N's rear side

Protocol details

Read more...

Contact

Kristoffer Sjöberg
kristoffer.sjoberg at galeno.se