Least-obtrusive way to get Android Auto/CarPlay in a GZG50 Century

[pugwonk]

I found another picture of the plug that goes into the back of the VCR (on https://buyee.jp/item/yahoo/auction/n1104189950) and it definitely looks like the socket that's in the car.

I think it's time for me to buy a VCR and engage some optimism...

[pugwonk]

I now have a VCR on its way from Japan. Not entirely sure if I'll keep it or not once I've finished probing its outputs...

[pugwonk]

Quick progress update on this... my VCR arrived, I fitted it into the car and it works great. My next job is to try and piggyback the output from the VCR and try to diagnose what each of the different pins does. I'm guessing that two are power/ground, and I'm hoping that three others are RCA video and L/R audio.

I think the sanest way to do this piggybacking without modifying either the VCR or the car wiring harness is to get both a male and female connector and splice my own wires in between. Fortunately there was a male connector already in the car (seems like it was used just to hold the unused connector in place), so I only need a female. A friend sent me to Connector Experts - you can take a few pics of what you've got and they will tell you what you need. It's an amazing service - the only slight problem is that the female connector they have for sale costs $99.85, which is slightly more than the entire VCR did (connector is this one: https://connectorexperts.com/i-30055696 ... ?q=cet1423).

I think I'm going to pay for it because frankly their service was worth it, but I just need to get emotionally prepared...

[pugwonk]

A whole load more digging seems to suggest that the KET connectors MG651110 and MG641113 might be what I want. I'm buying some from China...

[pugwonk]

To cut a long story short, I managed to out which pins the three RCA lines were. The good news is that my gamble was right, and the data was still RCA. The bad news is that my connector still isn't here yet so I can't try to inject video into the system just yet.

[pugwonk]

The good news is that my connectors arrived from China. The better news is that they fit perfectly into the harness. The even better news is that they sent me five even though I ordered one.

Link to buy the connectors: https://www.aliexpress.us/item/2255800566879201.html (bear in mind that I don't yet know if the male ones fit!)

The not quite so good news is that I misunderstood the Alibaba listing and I've only got the female connectors. I've ordered the male set as well but it'll be another couple of weeks before they get here. At that point I can start making my piggyback harness.

[pugwonk]

I might update this in future, but here as requested is my current understanding of the pinout in the VCR connector.

[pugwonk]

While I'm waiting for the 14-pin connectors to arrive from China, I made a pretty good start on getting Open Auto Pro running on a Raspberry Pi. I think this will end up being what I use for the hardware portion of this project. It takes a while get put together and set up, but the other headless AA solutions were missing a few features that I wanted (wireless AA; night mode going on with headlights; external GPS support).

They keyboard and screen are just for setup purposes... eventually my plan is that the unit will run in the car without a keyboard and with a touch panel over the original car OEM screen.

I've got the basics of it working but I still haven't quite figured out how to run it all from 12v (there are currently six USB devices involved in this!) and there are a few other connections that I haven't yet sourced. I think I can probably have all of the kit live underneath the gear shifter which would be handy because it's really close to the AV inputs from the VCR and also pretty easy to get to when I decide to modify it/fix it/upgrade it to a Pi 5.

I'm making notes on this as well and all of it will go into the main build thread that I'm going to write once I'm done (will link it here).

[pugwonk]

My connectors arrived from China. The good news is that they all fit nicely to the factory items, and I've managed to make a harness extension to go between the VCR and the car, and the VCR seems to work quite happily through it. This is just going to be a test harness - once I work out what all the wires do I'm going to have to make another one with the right lengths of wires on it for wherever I need things to go to. And that might take more than one version...

Things I need to work out now that I've got a cable I can mess with in between the VCR and the car:

• Do any of 7,8,9,12,13 change with the headlights or the car being in reverse? Optimistic, but hey...
• Audio ground (cut 10 as first guess)
• "video playing" signal (cut 14 and see if the front never realises there's video being played)
• Chassis ground (cut 11 if 10 wasn't chassis ground)
• Does shorting 13 into 14 make the TV controls disappear from the front screen?
• Which audio is left/right (cut one)

[pugwonk]

I think I'm done for tonight, but one of my big goals is definitely done: I can display video on the car screen through the VCR connector.