Renault "Tuner List" Head Unit/CD changer hacking - Controls

**mox** · 03-22-2006, 02:22 AM

Originally Posted by Vicne

If I'm using 2N2222 transistors and CNY74-2 opto-couplers, do you think I need to adapt some resistor values ?

I can tell from experience that finding the proper pull-up resistor can be a real pain. I used to build and sell MIDI-interfaces in the past and even with optocouplers coming from the same batch, I couldn't find a single resistor value that would fit all, so I ended up using a potmeter. All problems were gone when I switched to Sharp PC900 optocouplers instead of TIL111/CNY17.

I'd borrow an oscilloscope again, Vicne. Or wait until I bring mine to help you out

**Vicne** · 03-22-2006, 03:29 AM

Originally Posted by mox

I can tell from experience that finding the proper pull-up resistor can be a real pain. I used to build and sell MIDI-interfaces in the past and even with optocouplers coming from the same batch, I couldn't find a single resistor value that would fit all, so I ended up using a potmeter. All problems were gone when I switched to Sharp PC900 optocouplers instead of TIL111/CNY17.

Jeez, isn't that sensitivity particular to MIDI ? Indeed, googling for "sharp PC-900" almost only gives results about MIDI.
I already bought a CNY17-2 so I think I'm going to try with it, first calculating a theoretic resistor value, then trying (on the breadboard) with a potentiometer set on that value and see the result...

I'd borrow an oscilloscope again, Vicne. Or wait until I bring mine to help you out

Indeed, that would probably be useful if troubleshooting is needed. I'll tell you how it goes...
Thanks for the warning.

**slimmegane** · 03-22-2006, 05:39 PM

@Vicne, Do you have mode to test the strange problem of tracks?

**Vicne** · 03-23-2006, 02:00 PM

Originally Posted by slimmegane

@Vicne, Do you have mode to test the strange problem of tracks?

I could observe the problem indeed but it's not fixed yet. I definitely have to solve my hardware problems before I can go on with software.

**pippolippi** · 03-23-2006, 03:15 PM

Originally Posted by Vicne

I definitely have to solve my hardware problems before I can go on with software.

One thing: since you're going to take out 12v from the pc for the relay, you could also use that to feed the optocoupler connected to rx, and use RTS exclusively for the relay. It should work even if referenced to ground, so you can also forget DTR.

**jorgenuno04** · 03-23-2006, 07:30 PM

hello veryone,

I have this cable (see photo), and the idea is to connect a regular mp3 player to the radio through the 8 pin plug. I´ve already tryed and it doesn´t work. I believe that the pins aren´t the correct ones.

The cable has connections at pins 13, 14 and 15.

For what I´ve read in here, the correct pins are the 18, 19 an 20 being the 19 the GND, correct?

If this is wrong tell me how do I connect a mp3 player to the radio, please

Thank you

Jorge Silva

**pippolippi** · 03-24-2006, 02:37 AM

Originally Posted by jorgenuno04

hello veryone,

I have this cable (see photo), and the idea is to connect a regular mp3 player to the radio through the 8 pin plug. I´ve already tryed and it doesn´t work.

Because it's not supposed to work. Only newest model have an auxiliary input and it's the connector between the yellow and the blue one. If your radio doesn't have this connector and/or you cannot enable the aux input in the advanced menu it's not possible to do what you want.
You can read this thread and, following the reverse engineered protocol, build an interface (e.g. using a pic) to fake the presence of a compact disc changer and an analog to spdif converter (the blue connector has only an spdif input), then you can connect your mp3 player.

**Putput** · 03-24-2006, 04:24 AM

Originally Posted by jorgenuno04

hello veryone,

I have this cable (see photo), and the idea is to connect a regular mp3 player to the radio through the 8 pin plug. I´ve already tryed and it doesn´t work. I believe that the pins aren´t the correct ones.

As pippolippi stated in his post, its not suppose to work, Renault HU's uses the Blue Mini ISO connector to connect to a CDC and not an AUX input. Only an 'Update List' HU has a direct AUX input. If you have an Update List HU, look in the document I've attached to this post. It describes how to connect an AUX input to a Update List HU.
Good Luck!

***** DOCUMENT UPDATED *****

**Vicne** · 03-24-2006, 02:32 PM

Originally Posted by Putput

If you have an Update List HU, look in the document I've attached to this post. It describes how to connect an AUX input to a Update List HU.

Very good document.
Just a note : maybe you should insist that Tuner List models, even with an emulator such as ours, still needs a Analog to SPDIF converter...

**Vicne** · 03-24-2006, 04:08 PM

Originally Posted by pippolippi

One thing: since you're going to take out 12v from the pc for the relay, you could also use that to feed the optocoupler connected to rx, and use RTS exclusively for the relay.

True, that'd probably be better

It should work even if referenced to ground, so you can also forget DTR.

Mmmh, I'd be tempted to leave the negative DTR (you know, RS232 compliance and such :-) ).
I don't think it makes a problem to have positive via the PC power supply and negative via the DTR, does it ?

Edit : Btw, it seems obvious, but your circuit relies on the fact that the PC's serial port actually gives a negative voltage for low level of Tx. If the Tx is simply tied to the ground, it wont work of course... I think I remember that some laptops don't actually bother outputing negative voltage. Do you think we should care for that ?

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