Cheap FOCer 2 (Open-source, Low-cost, VESC 6 based ESC) (v0.9 Release. Beta testing ongoing)

JLCPCB has 50 in stock of the STM32F405RGT as of this moment. It’s been going in and out stock. Just gotta catch it when it’s there.

Don’t discount my ability to make stuff in this chip shortage. I’ve done it with the little FOCer. I’ll do it here too. And so can anyone else that wants to.


All hail the Shaman.


So pumped for this. Making a home made euc and a couple other projects.


I got the CFOC3 prototypes ordered. Gotta work on the new thread now.


Any of you guys that are planning to build CFOC3’s got any CFOC2’s for sale. I’ve got a buddy that could use a couple.

hi, are you looking for with already soldered connectors etc.? I might be able to give away a couple, but I would send PCB with all connectors (through-hole components) separately. I have some soldered, but not sure if at least two are remaining (soldering takes a while…). All my non-soldered PCBs have passed that so called “diode” check and I had no problems with soldered versions.

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I could take them any way you want to sell them. I’ve built a few myself, but don’t have any I’m ready to part with.

Well, depending on how fast you want them, I might be able to solder one (without power cables I suppose), flash firmware and test if it is possible to connect to it via USB. I have one pre-soldered with all wires. I could also give away laser-cut aluminum plates (not thick, 2mm) with holes for mounting it (holes are untapped, they are just cut by laser and work as a reference). If I give away you PCB with components separately I am worried that if you have any issues with them, I would not be happy. However if you would be willing to take two FOC2 with parts separately, I would give it away for a very very decent price (roughly what I paid for). So if you fail… I might give you some more. I have 5 spare pieces now.

That seems like a good option to me. Which parts will be separate? Just the through hole parts or also some SMT?

We would take care of the motor and battery wires and connectors.

Just TH components, capacitors etc. The board itself is fully assembled and as I said, all of them passed diode test (yes, there were boards I got that failed that test and I soldered them anyway and they were really defective). Basically you would get all of the components that are needed to complete soldering according to shaman’s guide. Nothing more complex. I would do soldering for another FOCer then and based on that I will make sure that you get all needed components, because it has been a while since my last FOC soldering job.

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Thanks. I’m going to take this to private messages just so I don’t hijack this thread any further.

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First off, thanks so much for the incredible hard work you (and everyone else) have put into the FOCer series.
I was in the process of pulling the trigger on my first 5 CFOC2 at jlcpcb, and realized CFOC3 is imminent.
Would it help CFOC3 development to donate to your paypal link above? Or anything else more specific? (beta hardware testing?)


Yes. Or maybe no. Give the man your money either way, he deserves it :heart:


I’ll take whatever you can give!


Question for the community. I’m trying to expand my understanding of the VESC code at it’s core but I’m trouble locating something. Where are the MOSFET PWM signals (H1, L1, H2, L2, ect) defined in the code?

I don’t know that much about the code either but I think what you are looking for is in bldc/foc_math.c at master · vedderb/bldc · GitHub function foc_svm
and bldc/mcpwm_foc.c at master · vedderb/bldc · GitHub function control_current
It looks like after the duty cycles are calculated in these functions, the pwm signals for H1, L1, … are set by timers in the #define TIMER_UPDATE_DUTY_M1(duty1, duty2, duty3) and #define TIMER_UPDATE_DUTY_M2(duty1, duty2, duty3) macros.
I could be wrong though :slight_smile: So it might be a good idea to ask in the discord channel. It seems there are a few people there with a lot of knowledge about the code.

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We are excited waiting for the Cheap focer 3 thread!! We wanna see the new stuff :wink:


I know I’m late to party, but this would seem pretty fitting


Hey Shaman,
I’m a little lost. I know you made other FOCers that are going to be closed source since you need to make a living. Is there still going to be an open source CFOC3 or have your plans changed?
Thanks for all your work!


The plan is still to open source it though I may strategically delay open sourcing it until I have production units ready to go.