Renault "Tuner List" Head Unit/CD changer hacking - Controls - Page 38

Vicne · 06-21-2006, 05:26 PM

I'm replying to myself, in case some hardware guru can help me.
Remember this ? :

Quote: Originally Posted by Vicne

I made a trip to Paris with the emulator and all worked well for about 1h30, then I began all of a sudden to have sound completely stopping

Well, here is the summary and the new observations of the problem.
- nothing seems permanently damaged
- it always starts to happen between 20 and 90 minutes after I start the car
- the emulator begins to show unacknowledged frames
- the problem increases during a few minutes: first one drop, than another after 30 seconds, then another after 15 seconds, then more and more up to the point where I get a link error and the emulator isn't recognized anymore
- if I turn the HU off for 10 minutes but let the PC on, when the HU is restarted it works again for a few minutes
- I already checked all the cabling and found nothing wrong.

My current hypothesis is that the head unit's HU_ON output that I'm using to power the optocoupler (see schematics) is overloaded and that a protection is triggered when the chip gets too hot, powering it down.

According to my calculations, I'm drawing about 10-15 mA from this pin. It seems a rather light load to me but well, this output is only meant to be a signal after all.

Does it make sense to you ?

Alternatively, it could be that the optocouplers overheat, but I can't see why they would...

Any advice is welcome, as always.

Vicne

Ale · 06-21-2006, 05:56 PM

Quote:

Do you know if Connection + and - pins are equal to TX/RX pins on tunerlist models?

I think it is a D2B bus signal.

Quote:

The PIC emulator project mantained by Ale works only on tuner and update list, right? or do you think it can fit for my radio too?

I tested the pic emulator only on my tuner list (scenic I 2003).

Ale · 06-21-2006, 06:10 PM

Quote: Originally Posted by Vicne

Well, here is the summary and the new observations of the problem.
- nothing seems permanently damaged
- it always starts to happen between 20 and 90 minutes after I start the car
- the emulator begins to show unacknowledged frames
- the problem increases during a few minutes: first one drop, than another after 30 seconds, then another after 15 seconds, then more and more up to the point where I get a link error and the emulator isn't recognized anymore
- if I turn the HU off for 10 minutes but let the PC on, when the HU is restarted it works again for a few minutes
- I already checked all the cabling and found nothing wrong.

It is possible that when your HU is getting warmer the internal baudrate clock shift a little, and get wrong data from PC. (or is your PC baud rate clock?) this is the first problem that i encoutered with pic emulator that has a +10% initial error in frequency. Try to measure the bit time, should be 104uS, with an oscilloscope (or the soundcard recorder!!)

Quote:

According to my calculations, I'm drawing about 10-15 mA from this pin. It seems a rather light load to me but well, this output is only meant to be a signal after all.

I get form pin 17 (Rm+12v) the power for my portable dvd that consume 950mA. All run ok in a two hour trip to sea.

Vicne · 06-21-2006, 06:43 PM

Quote: Originally Posted by Ale

It is possible that when your HU is getting warmer the internal baudrate clock shift a little, and get wrong data from PC. (or is your PC baud rate clock?) this is the first problem that i encoutered with pic emulator that has a +10% initial error in frequency. Try to measure the bit time, should be 104uS, with an oscilloscope (or the soundcard recorder!!)

I admit I didn't think of that at all.
But I guess the PC has a much more accurate clock than that, doesn't it ? Moreover, my last test showed that even with the PC running, just turning the HU off to let it cool down "restores" correct behaviour.
A jitter on the HU side could be an explanation, but I really find it weird...
I might resurrect the soundcard recorder indeed :-), and use the EPIA soundcard so that I can capture the behaviour when the problem occurs...
I hope it's not the problem, because I can't see how I could solve that :-(

Quote:

I get form pin 17 (Rm+12v) the power for my portable dvd that consume 950mA. All run ok in a two hour trip to sea.

Ahem... Yes, ok, so obviously that's not the problem :-).

Or could it be that I'm dragging too much current from data pins ?

And do you think a problem in the hardware adapter could be the reason (I know I was warned that those optocouplers are very sensitive to resistor values) ? You see, I really think my circuit is about 10000x more error-prone than products from both Via and VDO... :-)

This issue is driving me mad and I'd really like to get rid of it before going on holiday (end of july)... :-(

Thanks very much for your help. It's very much appreciated, as always.

s4uzer · 06-22-2006, 10:06 AM

Quote: Originally Posted by Graf

AND I AM LOOKING TO FIND PLACE INSIDE ON THE BOARD WHERE THIS CASSETE SIGNAL ENTERS TO AUDIO AMPLIFIER MODULE AND TO INSERT SOME WIRES ON THAT POINT AND BYPASS ALL THESE CD EMULATION ISSUE.

I think I will try the same thing. It's the last experiment we can try

s4uzer · 06-22-2006, 10:15 AM

Quote: Originally Posted by Vicne

Are you sure what they mean isn't that you need a "CD Changer Control" label on the front of your HU - which you have ?

Damn, this was their reply:

Dear Giovanni,
The ARNS001 is designed specifically to add a Sony CD changer such as the CDXT69. Unfortuantely you cannot use this as an Aux input to add an MP3 device.
You can purchase the ARNS001 from one of our distributors listed on our website.

Regards
Chris Brown,
Export Sales,
Connects 2

Quote: Originally Posted by Vicne

I'm afraid this changer is not compatible with newer head units. Where did you get this information from ?
The guy in this thread bought this RC026 changer and couldn't make it work in a 2003 Clio. Note that connectors are incompatible too, by the way.
According to this post, the RC026 is compatible with "Clio (up to week 43/1999), Kangoo (week 45/1999), Scénic (46/99), Mégane (48/99), Mégane Cabrio (02/00) et Laguna (50/99)"...

I was not so sure then

Quote:

You "adapted" ???
Do you have information to assume that all those connectors carry compatible signals ?

That was the only rear view identical to my radio, so I only assumed that. I wasn't 100% sure

Quote:

By the way, is there a model such as Radiosat mentioned on the front of your head unit ?

No, only philips cd changer control as in the picture here

Vicne · 07-03-2006, 04:10 PM

Quote: Originally Posted by Vicne

And do you think a problem in the hardware adapter could be the reason (I know I was warned that those optocouplers are very sensitive to resistor values) ? You see, I really think my circuit is about 10000x more error-prone than products from both Via and VDO... :-)

And guess what : that was it :-)

After checking all the connections once again, I discovered that ... I had put a wrong resistor value between GND and pin 4 of the optocoupler (see schematics) : 4K7 instead of the 1K I had calculated. I probably was too concentrated on positioning the components and picked up a wrong resistor that was laying around :-(

Anyway, I fixed that and made a 200km trip and back, and didn't have any link error. So the only think I'll remember is that the schematics and the software are OK :-)

Many thanks to all of you who helped me !

jakefricker · 07-11-2006, 05:34 PM

***** DOCUMENT UPDATED *****[/quote]

Thank you so much for your advice. It was so easy! And cost me £5 in parts!
I can now plug any MP3 player in to the stereo in my new Scenic. My mini ISO came with clamps and I just cut a mini jack cable to length and used plyers to crimp the holders in place! Woo Hoo! I bought my ISO connector from conrad-direct.co.uk I will gladly offer advice to anyone trying to do the same thing!

nation · 07-13-2006, 12:33 PM

Ale,
I am working with your design but i have a problem,
i use your schematic and programed the pic with the hex included and with the scope i can see a signal in the RX14 pin but i can't activate the spdif input in the HU,
something is wrong but i cant find the problem,
i tested with the pc and a max232 circuit and i can select the aux input but with the pic i can't
and i tested the pic connected to my pc serial port and i cant see any communication in the hyperterminal
do i have to do anything else with the pic code before program it?

higgins · 07-16-2006, 02:49 PM

Hey ppl, i hope some of yous can help me.
I have a grand scenic and the radio has a selection for aux port but i've looked high and low and i cant find it anywhere. Can you tell me what cable i need to connect my iPod and where do i stick that cable. Thanks a mill.

Vicne · 07-16-2006, 03:39 PM

Quote: Originally Posted by higgins

Hey ppl, i hope some of yous can help me.
I have a grand scenic and the radio has a selection for aux port but i've looked high and low and i cant find it anywhere. Can you tell me what cable i need to connect my iPod and where do i stick that cable. Thanks a mill.

You say you have a selection for aux port, then I guess your HU has "Update List" printed on the front.
If so, I think all the information you need to make this work is contained in this document created by PutPut (cfr this post)
Hope it helps.
Vicne

lond · 07-16-2006, 05:05 PM

I'm want to build the stand alone emulator, but where can I by a PIC 16F688? Or can I use a different model of the PIC-family?

//Marcus Löfstrand

Ale · 07-16-2006, 07:09 PM

Quote: Originally Posted by nation

Ale,
I am working with your design but i have a problem,
i use your schematic and programed the pic with the hex included and with the scope i can see a signal in the RX14 pin but i can't activate the spdif input in the HU,
something is wrong but i cant find the problem,
i tested with the pc and a max232 circuit and i can select the aux input but with the pic i can't
and i tested the pic connected to my pc serial port and i cant see any communication in the hyperterminal
do i have to do anything else with the pic code before program it?

Check the configuration word in the winpic should be 0x30e4.
if you use the internal oscillator check if the bit time is 104uS.
adjust value of register osctune (in the main routine) to obtain the correct time.