Joined
·
6 Posts
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:
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:
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:
