(03-16-2019, 10:55 PM)nJoy. Wrote: Hey, I am currently waiting for my RockPro64 for similar project. i am thinking of having it as an addon for the existing head unit. I wouldnt want to completely switch them, because I drive Volvo and they do not really like when parts from the car are removed. At least for now. Also there is other problems, like steering wheel controls and audio... Maybe you have did something already as this topic isnt really new.
Hey. I switched from Rock64 to Odroid XU4 for my carPC project.
For steering wheel controls there are a couple of ways to do. You can use Arduino ProMicro to connect the buttons on the steering wheel as a USB remote device. What I did is I used a specialized board called Joycon EXR which is specially built for such applications. However you need to check if your steering wheel buttons are resistive to know which Joycon board you need. They have other boards which work with CAN bus. The board is very easy to setup. First time you need to connect it to your steering wheel buttons on one end and to a Windows PC via USB. The board has a PC software for configuring. You just need to open the program and press the the buttons on the steering wheel. As soon as you press the button the software recognizes the keypress and you simply select the button action from the menu (ex volume_down or next_track). You can set up long press, short press and double press actions as well. It took 5 minutes from me to do that.
For audio.
With Odroid XU4 I used an external usb DAC board which is connected to my amplifier. In your case you can connect it to your AUX input.
Here is the link on Amazon
https://www.amazon.com/gp/product/B00RKW...UTF8&psc=1
If RockPro64 can be fitted with a DAC addon board from pine64 than you can use it as well.
As I was making all the system from scratch I got some weird noises from the speakers when the car engine was on. It's called "ground loop" Make sure you use a "ground loop isolator". I used a cheap one from Boss
Here is the link
https://www.amazon.com/gp/product/B000LP...UTF8&psc=1
This goes between the DAC output and AUX input
For power, (just in case you are interested :-) )
I had a smart power supply called Mini Box DC-DC USB 200 lying around from another project. It's not the cheapest solution but it is smart and can shut down your board safely as it detects when car ignition is turned off. Moreover it can automatically start the board when you turn the ignition back on.
Here is the link
https://www.amazon.com/gp/product/B00C6C...UTF8&psc=1
The harder way would be using the same Arduino sniffing for ignition switch and transistors to shorten the power management pins on RockPro64 (if the board has such pins)
I would love to move the project back to Rock64 if the guys from Pine 64 make an Android image which can be used with a touchscreen. Rock64 has an add-on DAC board for high quality audio however the TV-ish UI and the system overall are currently almost unusable with touchscreens. Don't know about RockPro64 though.
Hope this helps.
Good luck with your project!