I've had a few attempts to get Android Auto onto the OEM screen via GVIF over the years and now think I have a good solution. I'm using the standard GVIF used by a few members of this forum, Crankshaft (Android Auto head unit) running on Raspberry Pi and a rotary encoder for control. I'll share more details on the build once I'm done.

I have an electrical issue that I'm hoping more expert members can help me with. When taking power for the GVIF and RPI from the same source (the unused switched 12v plug in the boot area on the left hand side) I get shimmer on the screen when switched to the RPI source (attached) a pic. It's fine when the engine isn't running or if I power the RPI from one of the 12v accessory plugs in the cabin. I'd really like to power both from the switched 12v in the boot though. What am I doing wrong?

The wiring is like this (I've tee'd power from the input of the 5v USB socket directly to the GVIF) - please don't shout at me. I'm doing my best.

12v switched --- 5v USB socket --- Raspberry Pi
12v switched ---------------------------- GVIF




Piggy backing onto these connectors for power to GVIF

 

I don't have that problem, but I also used a stand-alone power supply to provide the necessary current instead of tapping from somewhere else.

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

That may help, but then again it may be totally unrelated.

 

Sounds like you need a filter on the power to the GVIF, maybe something like one of these:

 

Awesome - thanks guys. Is that consistent with moving the RPI to a different power outlet making the problem go away? The shimmer is only seen when power RPI and GVIF share the same 12v source.

 

I sourced my android media box power from the socket in the glovebox (actually spliced in from behind the glovebox and also used a converter like Cee Jay) . No issues such as yours.

Looking forward to a demo video....

 

Thinking of sighting the RPi under the arm rest and take power from the USB next to the iPod connector. Anyone know how many amps that can provide? @Sean W Hi Sean, haven't forgotten the help you gave me with this last year. Thanks again. Will do a video and write up once done.

 

portable audio interface has a 10 amp fuse I think. USB is fed through that.

 

Facing the same issue in my new car.

Video of the interference (it's present if the engine is running or not).


The appearance can be improved by adjusting brightness/contrast on the GVIF but then it's pretty washed out. Really wish there was a HDMI version of the GVIF unit, the image is very 90's CRT at the moment

kj07xk mentioned power filters, had a look on Amazon UK and wasn't too sure what to go for (the selection is rubbish compared to Amazon US). Might some ferrite cores helps on the GVIF power lead? (I've ordered some just in case). I'm taking power from the spare switched outlet in boot. If a power filter is the way to go, would someone mind linking me in Amazon UK, I'm a newb at this so a bit lost as how to improve the situation.

Cheers,
Andrew.

 

Try connecting the black ground wire to a nearby chassis ground point instead of the connector (as in right to the metal chassis, not a wire) with as short a wire as possible. If that does not do it, then power filters may help.

 

Thanks WhiteXKR. Will give that a go tomorrow. Appreciate it.

 

In addition to what Steve said, which sort of piggybacks anyway, maybe check ALL your ground points for the vehicle. The screen looks like a bad ground to me also. If ONE goes fitzy, all the others may soon follow.

 

Tried WhiteXKR's suggestion to ground black on the chassis, short cable (10cm), made no difference unfortunately. Also added ferrite cores to both ends of positive lead, also nothing changed. Then added this filter Also no difference

GVIF ground to chassis & ferrite


OEM image is perfect, GVIF is horrible. Because the OEM image is not affected I didn't check all the ground points like Cee Jay advised (other than visually, everything looks fine).


Also tried different AV in's on GVIF from the Pi, just in case. No difference. Last thing I can try is to power the RPi from a different source than the GVIF (currently both from the switched outlet in the boot). If I wanted to get power from the outlet by the ashtray, what's the best bet for getting access to the wiring? I've already got the side panel off and the trim around the gear selector.

Cheers.

 

Well, you didn't say THAT part before...

 

Yep, realised that would have been good to know. Sorry about that.