Thursday, May 19, 2016

CarHUD Update, Now only 5 Months after the last one

Where have I been?  I got sidetracked with the CHIP I got from Kickstarter.  That little computer is a lot of fun.

But I have made progress on the CarHUD.  Quite a lot in fact.

As I last wrote, I gave up on the LCD projector idea and moved over to a dual 4 digit 7 segment LED array from Adafruit.

I also acquired 2 Pi Zero's since I last updated the blog.

You can probably see where this is going.

I decided to swap out the Model B Rev1 with the new Pi Zero.  This was done in an effort to make everything more compact.  I also didn't like how I had soldered the OBD-II board to my prototyping PCB.

First I did some testing.




These 3 were done to try and figure out how to get the data to project to the windscreen of the car. (done with the old Model B Rev1 and a breadboard setup).

Then I desoldered a bunch of stuff and re-soldered everything back into a new setup for the Pi Zero.



Then I did some more testing.


This is a bench test of the Pi Zero setup without the GPIO buttons for mode and brightness changing.


 This is a full up, in car test, getting data from the OBD-II port.

Now you're probably saying to yourself, what about the OS?  When I thought about using the Pi Zero in the CarHUD setup, it was about 2 months ago.  I tried running my Yocto build of CarHUD OS on it, and it failed miserably.  So I tried building it with my checkout of Poky's Dora branch.  Still didn't work.

Fast forward a month and I search again for Yocto on the Pi Zero.  This time, I'm successful.  I come across this link: http://www.jumpnowtek.com/rpi/Raspberry-Pi-Systems-with-Yocto.html.

Basically it's the normal guide, but updated with awesomeness.  So what do I do?  I fork his meta-rpi branch into something I customized for the CarHUD.  It's here: https://github.com/xtacocorex/meta-rpi.

pycarhud and pyelm327 are still alive and well on BitBucket.  I pushed commits to pycarhud today as I got more stuff working.  meta-carhud is probably going the way of the ghost.

I'll end with a couple of links to the system working:
https://www.youtube.com/watch?v=LmRZrQ55Ob8
and
https://www.youtube.com/watch?v=eOhZsKN1oYw