Many people ask how to build one. Let me tell you it is not very easy.
The device consists of two parts a D2B audio controller and a Raspberry PI which handles the Bluetooth streaming. The latest version of the unit user Raspberry PI Zero – the regular, not WiFi version.
The two boards connect together via 40 pin header. The D2B unit receives audio via I2S protocol from the Rapsberry PI. The two units also communicate via serial interface. The Raspberry PI is powered by the D2B audio unit. The D2B audio unit also can reset the Raspberry PI board if it is not responding to serial commands.
Here is the schematics of the D2B unit. Jaguar D2B board
The micro-controller is Cypress PSOC4 4100 series. Here is the firmware it is running.
The Gerber files that one can use to make the PCB.
The fiber optic connector is 3D printed. Here are the model files. There are 3models for the 3 parts of the connector. The optical receiver is EAPLRBA0 the transmitter is EAPLTBA0
Instructions how to built the software for the Raspberry PI board.
You would need a micro-sd card for the Raspberry PI and a Bluetooth USB dongle (The ones marked with CSR 4.0 work fine)
I was very happy reaching this point. I was quite a few years of effort, but finally, here it is. Something I can offer to people – a useful product. A device which emulates the car CD-changer and lets you stream music from your phone via Bluetooth.
Following a short beta test period, this is the re-designed look of the CD-Changer emulator. The fiber-optic control board is now on top of the Raspberry Pi. You can see the fiber-optic transmitter glowing in red through the connector plastic housing.
The board says V3.0 because V1 was the “beta” device and V2 never saw the light of day. The board has the D2B controller OCC8001 as well as a Cypress ARM M0 micro-controller and finally power supply circuit.
Here are a few more pictures.
Naturally, I misspelled the URL on the board, should be iQury.us. Brain does not function as well as it once was I guess.
This is one of the first working prototypes. The box has a Raspberry Pi model A+ which does audio streaming over Bluetooth. I covered the box with copper foil to try an minimize the EMI interference.