[dijit]

I am about to jump head-first into an EV conversion on my trusty Honda Civic. It was a great daily driver for years, but now sits unused and ignored. In my research of components I came across the GEVCU and it is right up my alley, as I am a big arduino/MCU fan.

Unfortunately the price of a brand new GEVCU6 from EVTV is beyond what I can justify for my project, especially considering it is based on an open source project and I have many rapid prototyping tools at my disposal. So, I have recently set out to build a GEVCU for my EV conversion.

It took a little longer on 'the Googles' to find the board files, schematics, etc. for the latest versions but I was able to track down GEVCU5 files on an old google groups post.

[edited post, newest versions are still open source]

After obtaining the GEVCU5 board file and BOM, I have now begun the process of tweaking and building a board. I hope to document here and provide others with the means to do the same (assuming my board actually works when I get done).

WiFi
The wifi module used on the GEVCU5 is discontinued by the manufacturer. I have experience with the ESP8266 from various IoT projects and I believe that an ESP-05 is a good option for my GEVCU. I found that some of the original conversations on wifi for GEVCU dismiss the ESP8266 because it was buggy and not stable, however I think it has come a long way in several years. I have had success with these modules in various projects, especially when the power supply is clean and stable. I think it is a good fit because:

• small footprint
• probably FCC certified
• u.FL connector for external antenna
• 4-pin connection: RX, TX, GND, 3v3

I modified the board in Eagle to accommodate the ESP-05 before having the PCB made. Instead of trying to incorporate the ESP circuit, I stuck with the header for the module. This way the module can be easily swapped out, replaced, upgraded, etc. Should be convenient for testing purposes.

Obsolete and Non-stock components
I found that many of the components in the (now dated) BOM for the GEVCU5 are non-stock components on Mouser and most other sites. I was able to find substitutes for all but one component, and this last component has at least a 4 week lead time.

With the substitutions, my Mouser cart total is up to $244.65 with economy shipping. This is much closer to my budget.

PCB & Assembly
Of course the cost of the PCB and assembly have not been factored in yet. Perhaps others in the EV community may be interested, if I am successful, at a budget GEVCU and we can do a group PCB buy? Seeed Studio offers a reasonable PCBA service that may make this a viable option.

I'm really not trying to take away from EVTV, they are doing great work over there. But on the other hand I am a big proponent of open source projects and ensuring that those DIY-ers on a budget (which is usually most of us) are not isolated. This is a basic fundamental of open-source hardware and software. We all have access, we all can contribute, we all can improve.

In the mean time, I have a small run of PCBs using the new ESP-05 design. Now I am awaiting the backordered component from Mouser (I could not locate it at digikey or others). I plan to use my homebrew reflow oven for assembly, so I am looking at solder paste and many hours with a syringe and tweezers. Even valuing my own time at a reasonable rate, the overall project cost will still be considerably less than a brand new GEVCU6. Plus, I will be able to learn even more about EV systems. Stay tuned for updates. If others are interested I can post an updated BOM with the replacement components and the eagle board files.

Cheers!
dijit

Below is my current revision PCB:

 

[CKidder]

Ahh... Did you happen to check my github repos? Because both the GEVCU and GEVCU6 repos have a shield folder where you just might find GEVCU 6.2C board files. Those should be the most recent version that even exists. It's true that development of GEVCU has kind of tapered way off. But, the files are all open source.

https://github.com/collin80/GEVCU6/tree/master/Shield

 

[dijit]

Sure did! Even linked to it above. Unfortunately that is to the "GEVCU" repo and not the "GEVCU6" repo. Is there a separate repo with the GEVCU5 files? If so, I could not find that.

Sorry, I wasn't trying to call you out (although I guess I did....by name....lol). Thanks for this, and thanks for all the hard work paving the way. I hope to be able to contribute back to your project and design in some meaningful way.

The GEVCU6 added BLE (and optional GSM?) and removed WiFi. I found your posts regarding issues with the original adafruit BLE module. Were you able to resolve the bluetooth issues with the 6.22 revision?

I'm not sure that my specific application would benefit from the BLE option, which is why I chose to go the WiFi route.

Thanks again

 

[kevinjclancy]

I am seriously looking at buying the GEVCU from EVTV - It looks like your having not to much fun sorting out your custom made set up - If you are able to sort something out how much money can you save? - anyway my fear is that I will struggle working out the software to get my low cost chinese controller to work properly - as I am saving a bundle of money on the motor and the controller I see the cost of the VCU as bearable. I think it should be nice to log on to it with a tablet and mount the tablet on my dashboard.

 

[remy_martian]

Isn't one of the conditions of the Arduino license that ANY code written on it, and ANY hardware running on it, need to be open source?

 

[CKidder]

Isn't one of the conditions of the Arduino license that ANY code written on it, and ANY hardware running on it, need to be open source?

Well, it seems like a bit of a gray area in this case. The GEVCU software itself is fully open source. Everyone can go download the code and all the libraries it uses. The hardware isn't but technically it's not really an Arduino anything nor does anyone claim it to be. You happen to be able to compile for the Arduino Due and have it work but only because it does use a SAM3X processor. Basically everything else about it bears no resemblance to an Arduino Due or any other Arduino. The hardware need only be under the same license as Arduino hardware if one creates a derivative product. But, GEVCU is so far away from even an Arduino Due that I don't think you could really call it a derivative of the Due.