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4 BLDC for 1 VESC

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mac_cros
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4 BLDC for 1 VESC

Hi everyone :) 

My question is very simple : Do you think it is possible to drive 4 BLDC in only one VESC PCB ? I'm trying to make a 4in1 ESC for quadricopter application.

Thanks ! 

p.s : VESC is such a wonderful project :o Congratulation

TechAUmNu
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Yes just copy paste the design 4 times... lol

mac_cros
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Aha yes that's a solution...

I know you understood, but maybe it's possible with 1 STM32 MCU to control 4 BLDC Driver ? I didn't see something like that in the forum.

p.s : Sorry for my poor english.. I'm french.

Jacques Cros

tul00985
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No, thats not possible.

With the STMF4 and the ST Motor Control Library you can control 2 BLDC's with one MCU.

 

But with the VESC Firmware you just can control 1 BLDC

mac_cros
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Hi,

Thanks for your reply. I will find a VESC Solution with 2 MCU to control 4 BLDC now :) 

Jacques Cros

TheFallen
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Well no.
If you read what tul00985 wrote you'd see that VESC can only control one BLDC motor per STM32F405. 4x motors, 4x STM32F405s.
Why do you need to control 4 motors from one ESC? It's simpler and more robust to have a single ESC per motor.

nickw1881
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mac_cross, I am actually working on a 4 pack board right now for this very thing. I am targeting 48V, 30A max on 4 props, all running vesc 6 FOC. I have been eyeing the STM32F405 processor very carefully, as the processors are over 25% of the bom price just by themselves. It is an older fab process, and it looks like its nearing end of life. 

If you are porting to a cheaper processor, or if you are porting to a processor which can handle 2x the interrupt and computation load, please let me know!

mac_cros
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Hey,

@TheFallen simply because integrate a simple ESC on a drone instead of 4 PCB is much appreciated, because of the limited space and weight. I understood that we can piloted 2 motors with one MCU.. The actual problem is just the firmware, or the limited specifications of the STM MCU.. If we can change the MCU and do some modifications on the firmware, we can so control 4 BLDC motors with one VESC, it will be cheaper and more convenient.

@nickw1881, i'm very interested by your project, can you tell me more about it ? 

Thanks for your reply and have a good day !

Jacques Cros

tul00985
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@mac_cros

4 BLDC Motors on one MCU is possible (maybe no big thing)

4 or 2 BLDC with VESC Firmware on one MCU is impossible. The Reason: VESC is a very big thing, with a lot of functions and need many peripherals of the MCU. The FOC Code need's a Advanced Timer (TIM1).

I just know STM32 with max of 2 advanced Timers...so max of 2 Motors. But porting the Vesc code should be so complicated, that its easier to begin at Zero.

 

But if you would take the old BlHeli code (8bit AVR MCU -> no advanced Timers) and port it to a STM32 you could run 4 BLDC Motors with one MCU. But NOT with FOC!!!