sTeeve
Posts: 167
Joined: Thu Jan 22, 2015 1:02 pm
Location: Decatur, Georgia, USA

Re: Back up camera?

Mon Feb 22, 2016 1:28 pm

I contacted Jay at NAV-TV about this upgrade along with our new information. He says "I was told today we are good to go with the electric versions.".

I'm not ready to pull that trigger just yet. I want to do some more research.

Oh, and that Canadian unicorn doesn't have DCFC:

Image
2014 Spark EV

bicycleguy
Posts: 45
Joined: Thu May 14, 2015 5:19 pm
Location: Torrance, Ca

Re: Back up camera?

Fri Feb 26, 2016 3:13 pm

Finally got my little backup camera project finished ! I'd like to thank all on this thread for help and inspiration, especially solder. I learned a lot about how the CAN bus works.

Here it is in operation: https://youtu.be/gQagP5NV2ZY

The final and most difficult part was faking the head unit to display the video. This is also the part you won't need when someone figures out how to get the 'RearView Camera Calibration' working on the head unit, or GM decides to help out.

Image
This 2x2 inch proto board was developed and software written for the (super-Arduino) Teensy 3.2 powered micro-computer to do the job.


Summary of operation.
1. The ~$29 video camera is hooked to the head unit and powered by 12V tapped from reverse lights.
2. The board below is also powered by 12V from the reverse lights and taps into the Sparks SWCAN bus.
3. When the reverse lights turn on the board is powered up and immediately (and redundantly) listens on the SWCAN bus for shifter in reverse.
4. The board then sends an OBD (on board diagnostics) signal to the head unit to test the video input causing the video to display.
5. Every two seconds while still in reverse a tester present signal keeps the video going.
6. When shifted out of reverse, the board shuts down and can't cause any SWCAN bus, ONStar ext. glitches.

Nashco
Posts: 537
Joined: Wed May 29, 2013 12:00 am
Location: Portland, OR

Re: Back up camera?

Fri Feb 26, 2016 3:21 pm

Awesome. How do the rest of us get/make one!?! :D

Bryce

bicycleguy
Posts: 45
Joined: Thu May 14, 2015 5:19 pm
Location: Torrance, Ca

Re: Back up camera?

Mon Feb 29, 2016 4:26 pm

Nashco wrote:Awesome. How do the rest of us get/make one!?! :D

Bryce
Ya, thats the next step I haven't figured out, yet. You have to be a pretty handy nerd to do this as it stands. If you like reading schematics, programing Arduino's, figuring out and modifying other peoples software,
soldering .05inch pitch parts, using an oscilloscope, splicing into perfectly good wire bundles in your new car and trouble shooting, then..
THIS IS THE PROJECT FOR YOU !

I'm not interested in sourcing kits or being responsible for others mistakes but have thought about helping those who satisfy some of the above requirements. I think to make it reasonable I need to add a few LEDs
for trouble shooting(no oscilloscope req'd) and have a pwb fabricated to prevent wiring errors and maybe program the Teensy if you really can't handle it.

Still interested?

Nashco
Posts: 537
Joined: Wed May 29, 2013 12:00 am
Location: Portland, OR

Re: Back up camera?

Tue Mar 01, 2016 11:17 pm

I'm still interested as a back up plan to help all mylink users interested in making their car safer if the GM calibration number mentioned above turns out to not be feasible. I suspect your solution isn't Spark EV specific and would work on a *lot* of GM vehicles that use this same head unit but weren't equipped with a factory backup camera. This seems like a great thing to be open sourced so people can re-create, and maybe with enough momentum somebody will make a plug and play kit out of that design.

I've been interested in trying out a low volume run of custom PCBs and components, there's a place that specializes in this nearby me called Screaming Circuits:

https://www.screamingcircuits.com/

If you posted a schematic, parts list, and your source code, this would be 90% of the info needed to recreate this without a ton of effort on your part. It's hard to tell in the photo, but it looks like with a small, custom-made (and populated) circuit board, the pre-made Teensy board, and a couple of headers, no soldering would be required at all.

Personally, I'm pretty good at sourcing parts. I'm sure I could easily come up with a parts kit for the car that would make the harness part plug-and-play. I'm also good with CAD if that helps, either turning a schematic and parts list into a PCB layout or creating an enclosure with integrated connectors. I'm pretty bad with software and electronics design, so I'd hope somebody else could help come up with some LED indicator circuits and instructions on code stuff.

I still hope the GM calibration would make this all avoidable, but until we can try it who knows how it might work out...

Bryce

SparkevBlogspot
Posts: 499
Joined: Mon May 25, 2015 12:19 pm

Re: Back up camera?

Wed Mar 02, 2016 10:44 am

bicycleguy wrote:If you like reading schematics, programing Arduino's, figuring out and modifying other peoples software ... Still interested?
Is this the same as Spark DD project where you read out the battery stats via OBD using CAN?

http://www.mychevysparkev.com/forum/vie ... 662#p14662

I'd like to see the info as well. I might even try to make custom PCB with AVR (or even MSP430 for even lower power) and SD card to log the data. If you're only using Arduino library, it would make porting a lot easier. 32GB SD card could probably log 100 years' worth of data, though the flash cells may not last that long. Hmm. More time sink! :P

bicycleguy
Posts: 45
Joined: Thu May 14, 2015 5:19 pm
Location: Torrance, Ca

Re: Back up camera?

Wed Mar 02, 2016 2:46 pm

SparkevBlogspot wrote: Is this the same as Spark DD project where you read out the battery stats via OBD using CAN?

http://www.mychevysparkev.com/forum/vie ... 662#p14662
The same only different. :? Nothing's ever simple these days.

solder's Spark DD code ran on a Teensy using FlexCAN library and got data off the 2 wire high speed CAN bus. I ported it to run on an Arduino due running due_Can library. because thats what I had.

This task gets data from the single wire low speed CAN bus which requires different transceivers to communicate. This version runs on a Teensy 3.2 with modified FlexCAN library and a microchip mc33897 transceiver. I choose the Teensy because its smaller and cheaper than the due.

There's probably room on the board to cram the 2 wire transceiver and switch between them to do both tasks. (some other day)

SparkevBlogspot
Posts: 499
Joined: Mon May 25, 2015 12:19 pm

Re: Back up camera?

Wed Mar 02, 2016 5:49 pm

I don't know how much difference in code it might be with Teensy 3.1 and TI transceiver, but it seems there's already a board that has CAN + SD.

https://oshpark.com/shared_projects/VeJFD9qA

This is sort of what I had in mind, but using low power devices. But it sounds like you modified from FlexCAN lib for this particular application? Does backup camera stuff only work on single wire or can it work with SN65HVD232 CAN transceiver? Still, it'd be interesting to see.

I just read about solder from Kevin. Is that true?

http://www.mychevysparkev.com/forum/vie ... 6&start=20

bicycleguy
Posts: 45
Joined: Thu May 14, 2015 5:19 pm
Location: Torrance, Ca

Re: Back up camera?

Wed Mar 02, 2016 8:13 pm

SparkevBlogspot wrote:I just read about solder from Kevin. Is that true?

http://www.mychevysparkev.com/forum/vie ... 966#p14966
Wow, sorry to hear that. I sent him a substantial pm January 27 and never heard back anything. Seemed out of character as he was always very courteous.
Jeez, we were just starting to have some fun.

SparkevBlogspot
Posts: 499
Joined: Mon May 25, 2015 12:19 pm

Re: Back up camera?

Sat Mar 05, 2016 6:07 am

Has anyone tried one of these? It might be cheaper than custom solution, though may not be as good.

Boss BV430RVM Rearview Mirror with 4.3" TFT Monitor and Back-Up Camera

http://www.amazon.com/BOSS-BV430RVM-Rea ... B0090IA1T8

Image

There's also wireless video receiver/transmitter for $10 that may not require wiring, though again, quality might suffer.

http://www.amazon.com/2-4G-Wireless-Tra ... B008Z9E4DW

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