problems using CAN-USB with radio outside of vehicle?

[colletjr]

I've spent some time recently playing with my new CAN-USB, trying to attach it to my old radio from my 300 (left over from my nav upgrade).

It seems like something isn't right with it.

If I connect the CAN-USB's CAN_H and CAN_L lines directly to the radio, then I can power up the radio, I can send the acc/power_on packet (CAN id 000) to get the radio to turn on, and as expected, if I don't keep sending it, the radio will turn back off.

But here's the thing; if I send the packets repeatedly, the radio will stay on (as expected), but it will keep cutting out (the display goes dark for less than a second, then comes back to what it was before), and when it does, I can usually see the red light on the CAN-USB blink, and I can also hear the radio make a faint buzz (like it does when you first apply power). I hooked an ammeter up and I can see that when it does this, the current draw drops. It's as though it is resetting. But it doesn't reset completely, since the clock doesn't lose its time.

I thought it might be an issue with CAN bus termination, since the CAN-USB manual and everything else I've read insists that the bus must be properly terminated. I put a 120 ohm resistor across the CAN_H and CAN_L on the CAN-USB connector while doing this, and then I couldn't get any communication with the radio to work. I measured across the CAN_H and CAN_L pins on the radio itself and there isn't any termination in there.

Any ideas what is going on? I also tried broadcasting a larger stream of packets which I constructed from the data logs here, and it's the same thing; I can get the radio to turn on, but it keeps doing what seems like a reset.

For those of you who are using the radio outside of a car in a bench setup, can you describe your configuration in more detail? If the issue is just that I'm not sending the correct packets, please tell me what I'm missing. I'm hoping to connect the CAN-USB into the car next, but I'm a little worried that it isn't working properly on the bench, and I don't want to mess things up in the car!

Thanks for the help, and I hope Santa Claus was nice to all of you!

[SgtStank]

Have you checked the error codes that are causing the red light to flash? Is it a buffer issue or a bus issue?

When I first set one up here, I put together my CAN hub using the suggested terminating resistors but I kept getting bus errors. I finally removed the resistors all together and the bus error went away.

I also ran into buffer errors which were corrected by adjusting the COM settings for the virtual serial port (which is how I use the CAN-USB). There are also settings in the terminal emulator that runs my script to control the timing of the data sent.

Also from your description I don't see mention of connecting the ground. Since the ground is normally returned through the chassis at some point, yet still common, it is necessary to tie the ground from your CAN USB into your harness and power supply.

From your description of the buzz this sounds like either a ground issue, or the unit isn't getting enough juice to power up. What's your voltage drop to when you first supply power and the unit cycles through the CD changer? And again what does it drop to when you send the ACC-ON stream?

I've got more info if you can describe how you're connected a little better. I'll try to draw up something on what I found to work without issues for us.

Good luck and Happy Holidays!!!

[codekey]

You have to send a 4xx id that talks to ID 416(radio)

[colletjr]

Thanks, both of you! I saw the 0x4xx packet in Stank's script and that's good that you confirmed it. I just need to try it out again now.

I realized, BTW, that the "buzz" I hear is pretty similar to the one I hear in the car itself. I'm not sure if anyone else has noticed it, but if I sit in the car for a while with the ignition off and let the CAN bus go idle, and then I do something like insert a key or press a button somewhere, there's a very short and faint buzz that I can hear, which I realized (when I hooked up the CAN-USB) corresponds to the start of the CAN bus activity. I think it must be coming from the radio, and is a bit louder when it's out of the car and on my desk.

[Mad Max]

From what I understand ... the CAN interfaces do not use shielded wires only twisted pair. What you might try to do is use a twisted shielded pair for your interface wiring and ground the shield to the car chassis somewhere. I would highly suspect the "buzz" that you are hearing is related to your wiring acting like a radio transmission source. Remember the bus signals are clocking in at least AM signal range.

[stephan]

I did some direct discussion with colletjr in between and I think it's time to post some results to all involved here.
With help from colletjr I could start the radio. And in further process I found out that a '000 63 00 00 00 00 00' which is sent at least every 800ms is fully sufficient to let the radio stay alive. It's only the wiring which is of influence on the actions happening there. Colletjr is right to use a short cable (twisted or non-twisted) without resistor-termination; ground should be connected. Listening to the communication of a radio with an extra can-controller (Atmel At90Can128 which sends the wake-ups e.g. every 500ms) shows that any change of the wiring leads to a missing acknowledge which is expected to be sent by the radio. In this case it seems that the radio is receiving the signal and reacts to this by turning on for a second. But as no acknowledge is received by the sender (the connected controller) this one repeats the wake-up signal permanently as fast as it can. All together results in a cycling wake-up of the radio for a second an a pause of approx. 4 seconds.
To complete some data: The radio I played with is a 2004 with integrated mp3-6CD-changer with 2 big adjusting knobs from a 2005 Chrysler 300c.

Hope this helps someone.
If anybody knows the code for switching on the lights -please post. The '1C8 13...' or '1C8 03...' from the can-logger is not working.

[Tommy Kidman]

Where can I find CAN codes to turn radio on/off outside vehicle.
Codes are different for every radio/vehicle disributor ?
What is and where can I find "Stank's script"

Best regards.

[codekey]

I did some direct discussion with colletjr in between and I think it's time to post some results to all involved here.
With help from colletjr I could start the radio. And in further process I found out that a '000 63 00 00 00 00 00' which is sent at least every 800ms is fully sufficient to let the radio stay alive. It's only the wiring which is of influence on the actions happening there. Colletjr is right to use a short cable (twisted or non-twisted) without resistor-termination; ground should be connected. Listening to the communication of a radio with an extra can-controller (Atmel At90Can128 which sends the wake-ups e.g. every 500ms) shows that any change of the wiring leads to a missing acknowledge which is expected to be sent by the radio. In this case it seems that the radio is receiving the signal and reacts to this by turning on for a second. But as no acknowledge is received by the sender (the connected controller) this one repeats the wake-up signal permanently as fast as it can. All together results in a cycling wake-up of the radio for a second an a pause of approx. 4 seconds.
To complete some data: The radio I played with is a 2004 with integrated mp3-6CD-changer with 2 big adjusting knobs from a 2005 Chrysler 300c.

Hope this helps someone.
If anybody knows the code for switching on the lights -please post. The '1C8 13...' or '1C8 03...' from the can-logger is not working.

You have to send any 4xx ID to the radio. For example..

MyID = 0x415; // this can be any number between 0x400 to 0x4ff except for 0x416 and as long as no other modules are on the bus.
TX_Data[0] = 0xfd;
TX_Data[1] = 0x16; // radio id 0x416
TX_Data[2] = 0x3f;
TX_Data[3] = 0xff;
TX_Data[4] = 0xff;
TX_Data[5] = 0xff;
TX_Data[6] = 0xff;
TX_Data[7] = 0xff;


Dimmer ID is 0x210 and byte 2 value varies the brightness

[gerbot_3000]

I am in the process of adding one of these radios to my 1984 chrysler lebaron convertible, sure... it does not came with CAN bus equipment hehe... So i would need to find a way to emulate the turn on/keep on message for the radio WITHOUT using a laptop.

If somebody could help me with this or sell me a device that can do this it would be awesome.

Thanks!

[Balnk]

I am also in need of a way to get MyGig to power up outside of a car.

I'm willing to purchase a rig that will make this happen. Can anyone help?

Post here or PM please.

Thanks.

[carlos1984]

hi colletjr,

I am attempting to try this on a 2008 mygig rer radio and 2011 Ram radio, I was just wondering on the equipment I would need for this. I bought a can bus shield and arduino uno. Do I just connect the can H and can L wires directly to the corresponding locations on the radio and also where would the ground wire connect to?

[carlos1984]

Hi Guys,

I used this CAN USB analyzer
https://www.seeedstudio.com/USB-CAN-Ana ... -2888.html

I have two radios I am testing from Dodge.

One is from a 2011 Dodge Ram running at 125 K and the other is a 2009 Dodge Charger running at 83.3K

For the 2011 radio it is a REQ standard Cd player/radio with Digital display, when I send the turn on signal (000 63 00 00 00 00 00) at 800ms intervals, the radio responds, the lights come on but no display. There is also some CAN signals received from the radio.


For the 2009 radio it is an RER touch screen with navigation, when I send it the same signal it does respond also but I am getting the same problem you were having which is the screen turns on , there is enough time for me to see and acknowledge the prompt on the touch screen and scroll through the settings but then it turns off again and keeps repeating.

For both the radios I have done what has been suggested which is to connect ground and shorten the CAN H and CAN L wires but still getting the same problems.

[nemiro]

Increase your rate. Message needs to be sent every 100ms. Also, if your bus is not properly loaded, or the CAN board is not sharing a ground with the radio, it will not work right.

[carlos1984]

thanks for your help, I have connected ground to the radio, also what do you mean by bus not properly loaded? are these the setting, I am using a windows can program that came with the hardware.

[nemiro]

No, this is a hardware requirement to use 120ohm termination resistors. Read up on CAN bus hardware, and you will find it.