The tuner list is made by VDO, not philips. It's possible that the protocol is the same.Originally Posted by Vicne
Anyway, I repeated my experiment with a divider (18k/18k, what I had at hand, so half the voltage) and still nothing: the receive led doesn't light up this time, but the level is critical, since if I touch the connector it will light up and stay lit until I turn off the HU.
I also tried to connect the tx line (with a diode) to send the start sequence with no success. I think that the usb adapter gives too low a voltage, with a compliant serial port it works but not with the HU (since it probably needs the full 12V). Either that or I fried my HU
So I'll have to wait until someone comes up with a proper conversion circuit.