Audio and Video Interface MOST for Audi MMI 3G

[retali8]

I recently purchased http://car-solutions.com/en/audio-and-v ... mmi-3g.php and was in the process installing it today, however, when I configure my Raspberry Pi's composite out interface to PAL and connect it I see horizontal scan lines running through the picture. This occurs with other devices as well that are connected through HDMI to AV adapters that are set to PAL. Does anyone know what would be causing this? I've tried to change ground locations and everything but nothing seems to make a difference.

[Chortenia]

Hello.

Please, provide the video of the problem.
Also, please, say whether you connected other sources without the adapters to this interface.

Best regards,
Car Solutions Team

[retali8]

Sorry about that, I meant to post a video but I figured it out partially. It's a lot better than it was before.. I basically had a ground loop issue until I spliced the power/ground from the audio/video interface with the DVD drive power/ground in my car. I still have some waves in my video though. Do you know of anything else that might clean up the signal? I have HDMI2AV converters connected to it. I'll post a video of it later on though.

[retali8]

Here is a video of the problem. Sorry for the sound had the AC on in the car.

https://www.youtube.com/watch?v=63dKu7y-xJg

If you make the video full screen when you view it you will see the rolling horizontal lines in the video on the lcd. It was worse until I changed the video interface to where it gets it's power and ground from the same location as the CD/DVD changer. I do get power/ground for the devices I connect to it elsewhere though so I'm not sure if maybe that's why it's still a problem.

[Chortenia]

Hello!
Try to interconnect the bodies of all devices and don't place GND cables from the devices on the car body.
Look for a wire.

[retali8]

The way I have the video interface powered now is through the DVD/CD changer. I just tapped into the power/ground for it which significantly improved the picture. I then have a 5 port USB adapter that I cut the cigarette lighter end off of and have it piggy backing off another circuit in my fuse box then grounded on the cars frame. Are you saying I should also tap it into the same place as the video interface to get it's power/ground, or just only use the same ground? I don't think I can really tap that same power wire again because I feel like I'm already drawing enough power from it. I'll try and use the same ground though and see if that helps at all.

[Chortenia]

Hi.
Connect to GND there where you took +. You can power all devices from one place. And interconnect the bodies of the devices.
Best regards,
Car Solutions Team