OpenAuto Pro Custom HU Build Log
 

Going to log some progress here. This project might crash and burn but maybe a good solution can come out of it for these first gen coopers. I expect updates to come slowly but I will post them as I go for anyone following along.

I'm currently using OpenAuto Pro and I like it for the most part. But I want to step up the game a bit. I spent so much time working on cracking the kombi to swap from chrono gauges to sat/nav (https://www.northamericanmotoring.co...hopefully.html) that by the time I was done there I was too spent to focus on a proper HU build. Some pics of the current setup can be found here (https://www.northamericanmotoring.co...lity-help.html). Most of that thread is a confused mess as i had no clue what I was doing at the time.

I've taken the measurements of the current sat/nav system and the plan is to create a solution that will be able to fit cleanly into the current housing. A Raspberry Pi will be the brains and PCB800099 video controller. I'm also keeping track of some of this on the OAP site as well. I was hoping to get some help for the crew over there but parts of this are pretty specific (like the pcb shape).

I had a document of thoughts but the formatting was a mess when I tried to paste it here so pics attached instead.

https://cimg8.ibsrv.net/gimg/www.nor...1ce96becd1.png
https://cimg9.ibsrv.net/gimg/www.nor...55479b6498.png
https://cimg5.ibsrv.net/gimg/www.nor...a08d280891.png
https://cimg6.ibsrv.net/gimg/www.nor...b9b0b9ce2b.png
https://cimg7.ibsrv.net/gimg/www.nor...c047d8aa74.png

https://cimg5.ibsrv.net/gimg/www.nor...700d56d68a.jpg
https://cimg9.ibsrv.net/gimg/www.nor...32760420fa.png
https://cimg1.ibsrv.net/gimg/www.nor...28ba1601b1.png
https://cimg2.ibsrv.net/gimg/www.nor...331e6ca60c.png
https://cimg3.ibsrv.net/gimg/www.nor...820f9a35bd.png

Small update.

Prototype of the smaller control board for the menu button, rotary encoder, and lux worked as intended. The bigger main board has been a little more interesting. I didn't fully understand one of the ic's I was using so I'm still working through a few issues.

Here is the PCB render of the smaller board along with how it came out. I had to change the photoresistor I was using since the original was a victim of the shortage. The new one was smaller and i misplaced it about 1mm too high it looks like. I might try to heat the clear plastic piece and bend it slightly to see if I can get it to work. Everything fits almost exactly as the original.


https://cimg5.ibsrv.net/gimg/www.nor...38ee1f6c81.png
https://cimg4.ibsrv.net/gimg/www.nor...8d63055962.png
https://cimg6.ibsrv.net/gimg/www.nor...388cdd478a.png
https://cimg2.ibsrv.net/gimg/www.nor...af3692bf6a.png

PCB update
 

Update on this project.
V1.1 has turned out pretty well. Made 2 big mistakes. Messed up the design on the hub because I used a revised datasheet but selected an older chip. That part I could have been okay without since I don't really need a hub. But the other mistake was missing a connection from the touch controller to the pi. That mistake hurts a bit since... ya know, touch screen without a working touch and all.

What I do have working though:
12V power convert to 5V3A to power the pi (and peripherals).
Comprartor for delayed power shutdown
Line audio out
Accessroy switch sense for power down
Reverse sense turns on backup camera
Illumination sense turns on secondary board lights.
OBDII (read through usb)
RTC to keep time when powered off
***KBUS Not yet tested***
***PWM for LCD not tested yet***

I also de-soldered the connection from the original nav unit and I'll be able to solder it to the new board so I can re-pin the connector and use the original part.

Doing a redesign now for V1.2.
And since I like pain, I'll make a few changes and add different parts.
- Moving some of the holes in the board for more convenient connections.
- Going to make the hub bus powered instead of self powered.
- Will make sure I don't eff up and forget the trace for the touch screen this time.
- Adding an ADC (was using hub mic, but ADC on board means I can use a smaller mic)
- Adding a high side switch
- Also working in timer idea that will turn on the unit when it senses the door unlock. That will make boot seem shorter and might be fully loaded once buckled and ready to go.

Couple of pics of the process here
https://cimg8.ibsrv.net/gimg/www.nor...b37126bc43.jpg
https://cimg7.ibsrv.net/gimg/www.nor...ff9f9fa6c2.jpg
https://cimg4.ibsrv.net/gimg/www.nor...1d4c4b2f4f.jpg
https://cimg5.ibsrv.net/gimg/www.nor...feb6a34f14.jpg
https://cimg6.ibsrv.net/gimg/www.nor...1dc6546dd8.jpg
https://cimg9.ibsrv.net/gimg/www.nor...7a480de7e.jpeg

Looks like you’ve not gotten much interaction in this thread! I think it’s pretty cool what you’re doing here, even though I don’t understand it at your level. I find it fascinating that people like you exist, and can tinker about in your workshop to come up with an alternative solution to the factory interface. Good work!

Thanks @njaremka . Its been a learning process. Designing for my car, but the thought is that when I'm done, even a novice can order the board and raspberry pi and retrofit this to their own vehicle in a few hours. The prototype I've been running for 2 years now has been great. really nice to have carplay / anroid auto in the car.

Prepping the Unit
 

I now have the new board with revisions designed and sent out to be printed. I'll have it back in a few weeks. In the meantime I guess I'll take apart another spare I have and document the process here. This is what I did with the old unit so that I can keep the car looking as stock as possible.

First, I took the old navigation unit out of the housing its in. There are 6 screws on the side holding the top and bottom casing together.
https://cimg0.ibsrv.net/gimg/www.nor...6e7a1e76d2.jpg
Separate the 2 halves.
https://cimg1.ibsrv.net/gimg/www.nor...64be147758.jpg
Take the side with the screen and circuit board and flip it over. Remove 4 connectors, 1 screw, and then de-solder the 4 pads holding the board in place.https://cimg2.ibsrv.net/gimg/www.nor...adaf2d4b49.jpg
Use some flux and a wick and pull the solder up, then use some wires to twist the metal tab straight on all 4 sides so the board can be lifted out.
https://cimg3.ibsrv.net/gimg/www.nor...ff46f256ef.jpg
There are 4 screws on the back side securing the video screen. After that, all parts separated like this.
https://cimg4.ibsrv.net/gimg/www.nor...9702623e33.jpg
Next to disassemble the screen. Its pretty easier to see all the snaps holding it together. The only piece I’m interested in though is the back plate that has the mounting bracket attached to it. Since the new screen is slightly bigger than the old one, I used a dremel to cut the tabs off so I can fit it to the new screen.
https://cimg5.ibsrv.net/gimg/www.nor...a17ba8c4d6.jpg
Once the bracket plate is cleaned up, attach it to the new lcd screen with some jb weld. These are the measurements, I also took 80 grit sand paper and scuffed up the mounting surface of each side and then cleaned it with alcohol.
https://cimg7.ibsrv.net/gimg/www.nor...5b43f80472.jpg
Don’t smush the jb weld into the lineup marks, or add so much it comes out the mounting hole. I ended up having to take a little bit and drilling out the hold so I could mount it. Not a prob though since I got it before it hardened all the way.
https://cimg8.ibsrv.net/gimg/www.nor...3aba48d51e.jpg
Don’t smush the jb weld into the lineup marks, or add so much it comes out the mounting hole. I ended up having to take a little bit and drilling out the hold so I could mount it. Not a prob though since I got it before it hardened all the way.
https://cimg9.ibsrv.net/gimg/www.nor...6f40147ffa.jpg
Since the old screen was a little more thick than this new one, add a washer to it. I used some from a long forgotten project. They are probably #4 or #6. The first 2 setups I created I used only a single washer. This time I will be using 2 washers (even thought only 1 in the pic).
https://cimg1.ibsrv.net/gimg/www.nor...8644e150bf.jpg
Since I opted not to use a super long rotary encoder this one is a bit squished in there. The plastic around the knob needed to be trimmed slightly.
https://cimg2.ibsrv.net/gimg/www.nor...2e29250806.jpg
I also took the old board and removed the original connector. The board I designed take this connector into consideration so that it can be soldered in and the original plug from the car can be re-pinned and used here as well. This was pretty simple, I added some flux, a little extra solder and then took the wick and heated the solder covering the screws holding the connector to the board. I then added a long line of solder to all the pins and heated the entire are while I used some pliers to gently pull the connector out.
https://cimg6.ibsrv.net/gimg/www.nor...bf2c87ca31.jpg
Here is the new LCD screen with the resistive touch controller added. The tails just tuck under the unit and down in the cage.
https://cimg0.ibsrv.net/gimg/www.nor...b80bdb43e6.jpg
And now I just need to wait from my re-designed board to arrive. Should be here in about 8 weeks. I didn't build a prototype with the changes I made so I'm really hoping I didn't miss anything this time around.

Just to comment on your door sense idea, that’s exactly how bmw does their nav boot up, on r53, e46, e39 e53, etc etc and even up to modern cars. When there is ibus activity, ie door unlocked via remote or cylinder, door is opened etc you can hear the drive start spinning up so that by the time you are in an key in ignition it is ready.
Also a back or home key might be the better choice vs voice activation on the center stack, especially since there is a voice activation button close at hand on the MFL steering wheel controls that you might be able to somehow read and interpret. And on the wheel is a much better place than reaching out to center stack I can tell you from experience in my f31.
If you are the nice fellow who figured out the pin out etc to revirginize Chronos with a r270, thanks. I got to get rid of my useless nav (my whole side of town didn’t even exist 10 years ago when final map update came out) and get a working temp gauge instead thanks to that.

Any updates on this?

love this a lot!

I was planning on cutting up a universal 1din android unit to fit instead of the navi screen, but this is obviously nextlevel.

Was also wondering how oem mfsw buttons would work, and what leads are needed.


https://cimg1.ibsrv.net/gimg/www.nor...f507640dc4.png