Need help on drivers

Hi, i am a bit new on bldc motors and drivers. I am working on quadruped robot. First trying to build one leg for prototyping. Each leg has 3 degree of freedom. I am using ipower gbm4008-150t gimbal motor. As a motor controller i am going use stm32f429 board. I designed robot leg kinematic model and field oriented control model park and clarke transforms on Matlab/Simulink. My goal is first calculating each joint angle from matlab and send it to stm32f429 board via ftdi. Then i want to use raspberry pi instead of computer. Here comes my questions as i said before i am new on bldc environment need help for bldc motor driver. My research on internet i found this website and simplefoc shield and i learned some good information about foc. Can i use simplefoc shield for this kind of application? Also i am open to other suggestion because foc shield out of stock and my project deadline coming. I am looking boards on low cost area because i need 3 of them.

Hello @Coskun

Thank you for the interest in SimpleFOC. I am not an expert in this area and will leave the hardware cost and purchasing questions to people more qualified to answer.

This said, probably the answer about feasibility is yes, it could be done. Just to clarify on the requirements side:

  1. Model the joint motion in Matlab for 3 degrees of freedom.
  2. Send the three degrees of freedom as three angle targets to three stm32f429 boards using FTDI, here I assume you mean USB to SERIAL TX/RX and you read Serial as angle target.
  3. The three stm32f429 boards control three gbm4008-150t gumball motors using SimpleFOC running in angular target mode, I am assuming you have already angular sensors such as AS 5047U or similar and a diametrically polarized magnets attached to the motors.
  4. Eventually move the matlab commands to Raspberry PI sitting on the robot, sending commands to the three motors.

Did I get this correctly?


Thanks for reply @Valentine. You are right. Also my encoder is as5600.

Is your leg actually required to work and bear body load or just move, laying on a table to prove the concept? I mean do you expect the gbm4008-150t to really move the quadruped?

I wont build all robot just one leg for testing like on this videos. Test1 Test2 I know motors cant move all robot. My upper and lower leg sizes around 240 mm 3d printed parts. This my scholl project to show my models and controls which i designed and tested on matlab works on real world.

This is very interesting. Lets hope someone on this board helps you. What is your budget for the three FOC boards? I assume as a school project they have to be as cheap as possible. Also how much time you have?

I am looking around 70$ for three of them. I have one month to show working project but dont need to perfect i have a litle bit time for better demons. I hope someone to help me to choose board.

Check this out please

Yes i saw simplefoc shield but out of stock. Not sure to buying from china. Can i use it for this kind of application with using stm32f429?

You need to ask @Antun_Skuric about any of these.

There are some boards on aliexpress however I have no idea how to buy or if they work, you could take a chance perhaps? Search aliexpress for simplefoc.

Hey guys,

I am not sure that I’ll have any boards on my side for some time.
I do have 50 boards that need hand soldering, but I am not sure when will I have time to do it and basically all the regular manufacturers/web shops are out of stock.
So for getting a simplefoc shield the best way is to buy the aliexpress ones, they seems to be reliable based on the exepriences so far (and the lack of reported problems) :smiley:

Now in your case, you’ll be able to use the simplefoc shields in your project. There will be some lag due to the FTDI and USB communication, you’ll need to balance there a bit but in general I think that the simplefoc library and the shield can be a good fit for you.

Basically any board from the low-power applications (gimbal controller) will work for you. You can find some of them here:

I ordered simplefoc shield v2.0.3 on aliexpress and i get them 2 days ago. I am trying to build some test models to see how driver behave and how am i going to connect board to the my stm32f429 board. Because all i seen in your video or other youtube video’s plug it to arduino or nucleo boards. So when i connect simplefoc shield’s pins (5,6,9) to stm pins A8,E11,B15. I can’t get any voltage output from shield. I also connect 5v to shield for try. Power supply set to 12v. Which connection do i have make to use this simplefoc shield to use without plug to board like when we use arduino? My matlab model

and connections
shown like that.