Oh man i feel bad. To make sure the GND pad is not the issue i took out my 100w soldering iron and added some more solder to the back of one of the boards. I also replaced R48. I then connected it to the 5V supply and so far so good, the blue led (3.3v OK) lit up. The came the moment of truth and i plugged it to the 19V supply expecting another release of smoke… What can i say, ITS ALIVE!!!
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awesome job
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I recently had the shaman vesc here on my desk for a repair. Get sure you dont mix up one of the components, also you need to reflow the gnd pad of the drv really thoroughly and check for small shorts or cold solderjonts on the whole pcb. Especialy ics look like they seat correct but when you look closer you see there is no/wrong connection (I use a microscope app works awesome). I recommend not doing that work whitout hot air station it can work but its just pain in the ass. There should nothing start to smoke 
ahh i see you got it already lets hope it will work for you!!
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I’m really glad you got it working! (And not just because it would be bad PR for me if it was never fixed 
).
Let it be known that soldering the ground pad correctly on the DRV is absolutely necessary. This should be much easier with the v1.0 release that has the big hole directly underneath that pad.
@doomy let me know if have any more issues and I’ll do my best to help out!
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For those familiar with the VESC 4.12 hardware, R48 is not part of the original VESC design and is one my original additions.
R48 forms an RC filter with C9 and C21 that can potentially protect the DRV from the high voltage spikes on the main power rail. R48 also acts as a current-limiting resistor to help keep large currents from flowing to the DRV and damaging it. It appears this has done its job. Hopefully the DRV didn’t sustain any permanent damage.
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A couple of newb questions…
I’m assuming with a name like FOCer it should be reliable for foc right? What makes the other 4.xx models unreliable?
Then what’s the process here?
Step 1 pay the shaman
2 send the Gerber to a company to print the PCBs?what company?
3 order all the parts on the 2 bom pages? Mouser?
4 assembling
5 test power
6 boot loader?
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So i was busy beefing up traces and was able to spin up a motor. So far i have 2 working FOCers (on 19V)…
Next step will be testing on higher volatges and under load.
One of the still broken FOCers is showing 44V instead of 19 in the vesc tool.
Is the battery voltage measured by the DRV or MCU?
@Alpacaslapper
For parts and PCB i used jlcpcb and lcsc
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btw did you get to run your FOCers with the Aliexpress DRV’s`?
Yes absolutely, they are fine… Glad i was in time to also cancel the dispute.
I have alot of spare DRVs now so if anybody needs a repair…
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The MCU measures the main voltage supply. If it’s wrong, I suspect a wrong resistor value for the voltage divider that the MCU senses from. Check R32 and R34.
Before I look into the materials further, can you tell me about how much you have invested? How many completes will you have for your investment?
I’m waiting not very patiently lol, should I wait for shaman to sell as a diy kit or get er done myself lol.
@Alpacaslapper you don’t have to pay me. You get all the files you need from my GitHub repository. See the link in the original post of this thread.
You download the gerber files and then upload them to a PCB manufacturer like JLCPCB. They make the PCBs and then ship them to you.
You use the BOM file to buy all the parts you need from a distributor like LCSC or mouser or digikey.
You then assemble and solder the board yourself like @doomy did.
Yes you will have to load the boatloader with a stlink when you first program it.
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If I build one from your files, I will credit you, your hard work will be improving my ride. A donation for your work and your work moving forward with the other focers, will come your way. While I appreciate free, I also appreciate the time and commitment invested. I want foc again and don’t want to pay 200$ for a reliable vesc.
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Do your best to solder the positive cable to the solid core copper
You also want to effectively solder the ground cable to the solid core copper like in this picture
Also solder-bridge all of the current shunt resistors (R11 and R27) to the solid copper like in this picture
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I appreciate you wanting to help support me! However, please understand that this all is still based on 4.12 hardware. It is capable of FOC of which one of beta testers has effectively done but VESC 6 based hardware is known to FOC better. Just setting expectations here. Also I would wait for the v1.0 release if possible. It will have a few fixes and alterations that make DIY assembly easier.
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I prefer R48 to blow* instead of a DRV.
- Question though, could it be expected that the R48 could fail less elegantly & faster than the DRV under a high current condition faster than a DRV leaving a rider with no brakes, in which case would prefer to slowly fry a DRV.
I guess the choice in that case is to hardwire the R48 pads?
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Update:
Got 3 working FOCers now. Including the first one i soldered, i had to resolder the DRV chip i removed but it was not working anymore so i put on a new one and it was good.
I also found how to test if the GND pad is attatched. Use the diode tester on your multimeter between GND and R48.
If GND is not connected it will read ~2.9V
If GND is connected it will read ~2.6V
I sucessfully run FOC motor detection on one of the FOCers
This is so amazing 
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So if you get the free/older design does this make it a
Stupid FOCer?
Unfortunately I’m not familiar with how the DRV8302 fails during operation. Metal film resistors, like R48, can fail with the result either being open, change of resistance, or short. If you don’t want R48 then yes you can just solder-short the pads of where R48 would be. Honestly I don’t see how the presence of R48 could hurt.
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Sweet! Also good that you found a way to test! Does that method hold true for multiple units? Also, what FW version are you using?
Keep us updated on your progress!