6dof 6 BLDC guidance

Hi. I made a 6dof platform with hobby servos and arduino. It works fine, but it’s imprecise because of the gearing, backlash, analog pots for feedback, etc…
I want to redo it, better, with help of simpleFOC, on 6 bldc gimbal motors direct drive.
I could use some guidance on how it would be best to proceed, because i have no previous experience with bldc and encoders/sensors, but i’m willing to learn.

Board: ??Arduino Mega(i am not positive it has enough i/o and processing speed)? Maybe Nucleo F446RE?
Motors: 6 * 2208 90KV Gimbal motor
Drivers: 3 * BGC 3.0
Position sensors : ?? no idea yet

Feedback kindly accepted.

Hi @totaltripp, your project sounds awesome. There are a few bgc variants out there, I guess you are referring to a dual axis gimbal controllers with atmega328p on them. So i guess simplefoc will be running on the 3 bgc, right? The mega will then be sending commands to each bgc, perhaps using simple rx/tx serial?

Simplefoc won’t be running on the mega so i don’t think you’ll need more mcu power there.
I found the process of getting simplefoc running on bgc a bit tricky, mine didn’t have an arduino bootloader on it and I was unfamiliar with the process, I used a nano as a programmer (arduino isp) to flash a pro mini bootloader.

I’ve been meaning to buy a storm32 3x gimbal controller. Not tried those with simplefoc but the stm chips in them are 32bit and 72mhz. Also i suspect dac will be 12bit instead of 8bit.

For more info read @blackblue007 post here:

I find the magnetic sensors pair nicely with these small motors. Do you have a 3d printer that can be used to design enclosure for a magnetic sensor board?

Yes, i have a 3d printer. So i could use magnetic sensors.
Yes, the idea was that arduino sends command to each bgc. I am also unfamiliar with devices that do not have arduino bootloader, so maybe bgc 3.0 is not the best idea. If possible, i would stick with the simplest solution that allows me to do what i want, which basically is:

  • control 6 bldc independently, precise, fast, reliable but also perfectly in sync when requested
  • be able to have positional control from pots, a remote, or similar
  • be able to interpret data from an IMU or even two, with their values averaged, and process it in real-time so that the device self-stabilises

Can i use 6 SimpleFOCShield V1.3.1 with gimbal motors and magnetic sensors connected to an arduino mega? Does the arduino mega have enough I/O for the 6 shields, for an IMU, some pots, some buttons, a display, etc.

You can stack 2 shields on 1 uno. So you’d be looking at 6 shields, 3 unos and 1 mega.

Possible but not sure if I’d go that route.

My advice is to start with a single shield and try it with your motor. Then add a mega and work out the comms. It’s unlikely you’ll get the hardware right first time.