Inside the Volkswagen / Skoda Bluetooth Car Kit

Inside the Volkswagen / Skoda Bluetooth Car Kit

The bluetooth car kit is built around a TDA7590 a high performances, fully programmable 24-bit, 120 MIPS. Digital signal processor (DSP), designed to support several speech and audio applications, as automatic speech recognition, speech synthesis, MP3 decoding, echo and noise cancellation.

Nevertheless, the embedded CODE Cs bandwidth and the generic processing engine allow to proceed also full-band audio signals. The large amount of on-chip memory (128 Kwords), together with the 16 Mwords external memory addressable and the 32 general purpose I/O pins permit to build a DSP-system avoiding the usage of an additional microcontroller.

The presence of serial and parallel interfaces allows easy connection with external devices including CODECs, DSPs, microprocessors and personal computers.

In particular, the debug/JTAG interface permits the on-chip emulation of the firmware developed. Further, the presence of the timers and watchdog block makes TDA7590 suitable for PWM processing and allows the integration of a system watchdog.


2 thoughts on “Inside the Volkswagen / Skoda Bluetooth Car Kit”

  1. Very nice.

    Now, if only we could do a little investigative work to determine the coding which would activate the LED light (green/amber/red) in the overhead control panel. The dual diode (red and green) LED exists on the overhead module and the LED electrical wiring from that module exists in the cabling that goes to the BT module. And the big black multi-pin connector within the BT module connects to traces on the PC. And those traces have appropriate components for driving the LED current in both direction (one way for red; one way for green; and rapidly switching directions for amber). And the traces on the PCB do connect to the microprocessor/DSP chips. So the only thing missing to activate the LED is the firmware code.

    I’d bet that the code already exists in the firmware. And the only reason why we don’t see the LED light up is because that section of code is not being used. I’d further bet that simply enabling one bit on the -77 BT module’s “code” will activate the overhead LED.

    A prize goes to the first person who can identify the correct bit to toggle in the code using a VCDS.

  2. I too would be interested in this, as I am trying to get all of the wiring sorted out. In a 2009 TDI Golf with the 310 radio, but never ordered the Bluetooth or MDI when we got the car. The whole story is here: regarding the retrofit.

    Where I am stuck is at the Overhead console, and how to integrate that with the Bluetooth (see here: and How to integrate the harness for the Bluetooth and the MDI. Any help would be appreciated. Thanks

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