I'm a bit of a nerd and I like the idea of Android Auto in my 07. The Grom looks really interesting but a bit out of the price range I would be willing to spend for what I think the sum of it's parts are (could be wrong/just an impression).

Has anyone successfully or tried/failed to make their own interface with any SBC out there? I have a spare RPi 3B I'm looking to do something worthwhile with.

 

Well... There is Android Auto / Apple car play dongle that is needed with the system to enable it... Maybe you can get one of those and try to play with it ?

This would be an interesting subject, you just to know where to connect with the car's screen and if you could use the touch screen. That part could be pretty complex if you don't know what your doing... I am sure it's all documented someplace but, you have to get connected to one of the modes to use it (Radio, XM, Aux, etc)...

Good luck on this one...

And the one I am using can be had around $500 or so, and it is worth it... as all the complex things are done and it's just a plug and play thing...

 

Maybe that's the cost of entry to take care of all the loose ends and complexity.

 

Yes you are wrong, although doing your own is quite possible. It depend on how much you value your time and of course your skill. If I recall correctly Lexus use the GVIF protocol for it's imagery so you would probably need to convert the signal inline (ex: from an hdmi source) but I'm pretty sure there is cheap converter out there. But like everything else, devil is in the details. By that I mean there is quite a huge difference between spicing a few wires, install an aftermarket switch inline and call it a day and a more elegant solution that integrate fully in the system and keep all other features functional. For example the "easy" way would be the aftermarket manual switch but then you'll have to press the switch back before backing up for the camera to display in the screen for example... Unless you want to dig deeper and automate the process by analyzing all the signal that are triggered for a few of the car operation like switching sources, etc. Then you'll need additional hardware and you'll need to put more time. Then if you want it to work 95% of the time you'll need to put in more work and testing. You can do it as a hobby but I wouldn't expect to spend less that an existing solution if you add a bit of value in the time you put in. And don't forget unless you remove completely the radio and install it on a workbench you'll have to do all your research bending and working upside down to access all the wire you need to you'll probably add a few scratch in your interior here and there. Good luck

 

Keep in mind, time is money. Your time has value, so if your going to put 100's of hours into this when you can spend $500 on a kit, would it be worth it in the long run ?

Again, this not going to be easy but, if you get some place, make sure you document everything you try... I think a TON of people would love an option like this, a $100 parts (a PI and a Auto-play dongle) and a few custom cables to add Auto play/Car play to their car.... Maybe you can make the cables and sell a kit if you pull it off..

Just remember...

"The Only Difference Between Screwing Aroundand Science Is Writing It Down" - Adam Savage (MythBusters)

It applies to any project like this...