Skoda Amplifier: Enable Sound via CAN Bus

Hello everyone,

I have a Panasonic EAA098A amplifier (part number 5C6 035 456 A) from a 2014 Skoda Yeti that I'd like to test. I have an Atmel microcontroller with a CAN interface that I plan to use for this.

I've done a little research, and if I understand everything correctly, this is a 10-channel amplifier with 4 analog high-level inputs, a crossover, and outputs for 2x3 speakers in the front and 2x2 speakers in the rear. It is activated via CAN bus messages.

Can anyone tell me what Telegrams these are, or at least what their IDs are? I recently had a friend bring in his Yeti, and I briefly connected to the CAN bus of the navigation system and created a log. However, when I turn it on, there's so much activity, and I have so many IDs that I can't identify, that it hasn't really helped me.

Greetings,
Christian.

Hello,

I join the question .

Today, I connected a 2010 Octavia RS to the diagnostic cable. It has the amplifier installed from the factory (part number 3T0 035 456), as well as a Bolero head unit and an FSE (phone module).
"I'm not getting any sound with the RNS510. The reason is that every VW radio/navigation system doesn't send the signals needed to activate the (Skoda) amplifier. In VW, this seems to be controlled through a dedicated line or by adjusting the signal level on the existing lines. It's also possible that information regarding fading/balance is being transmitted."

I created a trace once with the Bolero and once with the RNS510.

First, I filtered out all the IDs that I knew had no influence. I also removed the IDs that were sending the same data. The following IDs remain:

Power-on procedure for Bolero:
0x361, 0x439, 0x557, 0x56F, 0x625, 0x63B, 0x661, 0x66C, 0x66F, 0x67A, 0x67C, 0x6C5, 0x6C6, 0x6C7, 0x6CB, 0x6D2, 0x6D5, 0x6D8, 0x6DB.

Power-on procedure for RNS510:
0x2A1, 0x436, 0x507, 0x557, 0x56F, 0x5A1, 0x5A3, 0x5AF, 0x604, 0x63B, 0x661, 0x66C, 0x66F, 0x67A, 0x67C, 0x67D, 0x6C6, 0x6C7, 0x6CA, 0x6CB, 0x6D2, 0x6D8, 0x6DB,

The Bolero now sends the following IDs, in contrast to the RNS510:
0x361, 0x439, 0x625, 0x6C5, 0x6D5

To the best of my knowledge...
* All xAx messages from the navigation system.
* All x6x messages from the radio.
The RNS510 broadcasts both radio and navigation information.


Does anyone have any ideas about which IDs we could exclude?

Sure, here's the translation:

"Best regards," or "Sincerely,".
Gerald.

Hello Gerald,

Although I'm not finished with my project yet because I'm short on time, I'll write down what I've found out so far:

My amplifier receives a fixed volume level from the navigation system, and everything else is handled by itself.

IDs sent by the amplifier:
433, 56F, 6D8
6D8 includes, among other things, the current volume level, appears periodically, and seems to represent the status.

IDs from the navigation system.
2A1 435 436 507 55B 5A1 5A3 5AF 604 661 66C 67A 67D 6C6 6C7 6CA 6CB

What's interesting here is the 6D8. It's used to adjust volume, fader levels, and possibly other settings.

Volume:
6C7 80 07 2B 55 XX XX 00 00
6C7 C0 22 22 00
I still need to test this a bit more, but the two 'XX' values indicate the volume. As far as I can tell quickly, they represent the start and end volume for a fade. If you set both to the same value, the volume will be set immediately.

Fader, ...?
6C7 80 05 2B 57 40 04 01 04
6C7 0 2 C0 00
I haven't looked into that yet.

In addition to the main telegram, there's always a 4-byte telegram that follows. It's essential, and I still need to figure out exactly what it does, because the RNS doesn't always send it immediately after the volume, sometimes it's omitted, and then it appears before the next volume change. In any case, they always alternate. The same applies to the fader.

...I couldn't resist and spent some more time today working on the amplifier. If the ignition is on, the power-up signal and the volume setting are sufficient; otherwise, the situation is as follows:

Amp Einschalten (50ms delay):
436 1A 01 05 00 00 00 00 00 //Bus aufwecken
6C7 2B 50 01 //Amp Einschalten

Bus am Leben erhalten:
436 1A 01 05 00 00 00 00 00 //alle 100ms

Lautstärke einstellen
6C7 80 07 2B 55 xx xx 00 00
6C7 C0 22 22 00

Greetings,
Christian.

It's BAP communication. Try to match your CAN traces to code listed below. Maybe it will help. Regards.

Code:

package vdo.p2.most.svwcanamplifier; public abstract interface VWCanAmplifierSFktIDs {   public static final short MOST_CATALOG_VERSION = 511;   public static final short BASS = 517;   public static final short MID_RANGE = 518;   public static final short TREBLE = 519;   public static final short LOUDNESS = 522;   public static final short MUTE = 523;   public static final short AUDIO_PILOT = 524;   public static final short SURROUND = 525;   public static final short SOUND_CHARACTERISTIC = 526;   public static final short DYNAMIC_COMPRESSION = 532;   public static final short SDVOLUME_TABLE = 533;   public static final short POWER_MODE = 545;   public static final short CHANNEL1 = 769;   public static final short CHANNEL2 = 770;   public static final short CHANNEL3 = 771; }

Code:

package vdo.p2.most.sbapamplifier; public abstract interface BAPAmplifierSFktIDs {   public static final short MOST_CATALOG_VERSION = 511;   public static final short FBLOCK_AVAILABILITY = 512;   public static final short BAPCONFIG = 514;   public static final short FUNCTION_LIST = 515;   public static final short FSGCONTROL = 525;   public static final short FSGSETUP = 526;   public static final short FSGOPERATION_STATE = 527;   public static final short POWER_AMP_ON = 528;   public static final short CONNECT = 529;   public static final short INPUT_GAIN_OFFSET = 530;   public static final short DYNAMIC_VOLUME_CONTROL = 531;   public static final short DYNAMIC_RANGE_PROCESSING = 532;   public static final short CHANGE_VOLUME = 533;   public static final short CURRENT_VOLUME = 534;   public static final short BALANCE = 535;   public static final short FADER = 536;   public static final short BASS = 537;   public static final short MIDTONE = 538;   public static final short TREBLE = 539;   public static final short LOUDNESS = 540;   public static final short SUBWOOFER = 541;   public static final short ROOM_MODE = 542;   public static final short SURROUND_MODE = 543;   public static final short SURROUND_LEVEL = 544; }