$50 Walmart hoverboard to robotics platform

[NiHaoMike]

Walmart was selling $50 hoverboards on Black Friday so I got one to hack into a robotics platform. $50 for two high torque brushless motors, two motor drivers, and a battery is hard to beat.

Inside are two motor driver boards, one for each side. The microcontroller is a GD32C230C8T6.

I found firmware for a similar architecture except the microcontroller is different.
https://github.com/flo199213/Hoverboard-Firmware-Hack-Gen2

Is there a similar project for the boards I have or an easy way to port the code?

[Doctorandus_P]

I am aware of Vesc, Simplefoc and Odrive.

If you search hackaday for BLDC drives you also find a bunch of smaller open source projects, and STM32 is quite popular among them.
ST itself also has reference boards and sourcecode.

I always found those hoverboards weird contraptions, but USD50 for two (geared?) BLDC motors, drivers and batteries is quite a bargain.
I do recommend to put the batteries in some kind of metal can, just as a precaution for when they catch fire.

That other project you found uses an GD32F130C8. Such changes usually don't mean much. You probably have to meddle a bit with the software and probably change some pin assingment and other small things. The GD32F is also mostly peripheral compatible with the STM32 parts. If you are unfamiliar with this, then I suggest you start with some generic development boards to get up to speed with your toolchain and uC, just to not wear down the FLASH reprogramming cycles of the uC on your motorcontrollers.

[thm_w]

The board you have is not the common generic model that was popular a few years ago. It seems somewhat cost optimized.
Have you looked at the motors yet?

I ended up using a "500W" alix bldc driver, cost ~$15, as its much more compact than the original board. But the original board could be very useful, for a more powerful robot.


Had this saved, forgot to post:

Now the interest in hoverboards has tailed off there are a lot cheaply available on the second hand market.
You can find a lot of projects on Hackaday, etc. for interesting designs. Sewing machines, go carts, robotic arms. Anything high torque low RPM may be suitable here.

If you are into motors and drivers, there is quite a lot in them. I paid $50 for a somewhat working unit, but you can even find them for less than that if they are non-functional. I would suspect if its not working, the battery or charger has died and the parts inside are still good. Some reports are that FETs had shorted however.

Here is what mine contained:
- 2 channel BLDC driver (STM32F103R), open source control software available
- 2 BLDC motors with tires, hall sensors, 6.5", 350W, ~16RPM/V, 36V
- 2 IMU sensor boards (each has 2 opto-interruptors, 1 GD32F103C8, 1 MPU-6050)
- Battery pack 10S 4400mAh, with BMS 160-180Wh
- Wireless module (bluetooth audio?)

This seems to be the most common version, although a few variations are out there.
I haven't dug into the battery pack yet, but it claims to use LG cells, and has a BMS board (see ifixit teardown). If you are a cautious person, use your preferred battery source instead, and just recycle this one.

It is made cheaply, but, a lot of the parts are of high quality. The machining on the aluminum wheels is great. The main BLDC driver board uses Rubycon capacitors, etc. Assuming they are not fake..

More photos and info:
https://github.com/EFeru/hoverboard-firmware-hack-FOC (FOC control, might allow higher RPM?)
https://github.com/EFeru/hoverboard-sideboard-hack-STM (the IMU boards)
https://discourse.odriverobotics.com/t/project-hoverarm/441/2
https://www.ifixit.com/News/7821/swagway-teardown-hoverboards

[thm_w]

I always found those hoverboards weird contraptions, but USD50 for two (geared?) BLDC motors, drivers and batteries is quite a bargain.
I do recommend to put the batteries in some kind of metal can, just as a precaution for when they catch fire.

That other project you found uses an GD32F130C8. Such changes usually don't mean much. You probably have to meddle a bit with the software and probably change some pin assingment and other small things. The GD32F is also mostly peripheral compatible with the STM32 parts. If you are unfamiliar with this, then I suggest you start with some generic development boards to get up to speed with your toolchain and uC, just to not wear down the FLASH reprogramming cycles of the uC on your motorcontrollers.

They are a high pole count BLDC, shouldn't have any gearing.
This can be really useful for certain applications, where you want high torque low RPM. Optimal RPM is 500-700 or so for a ~40V battery. With FOC you could go higher.

The GD32E230 is not a clone of any ST part I know of, so, its going to be a decent amount of work to port. For me at least, I'm not a software expert.
Then if you want true positional control, have to remote mount the encoder (like the odrive forum link above), or integrate it into the motor somehow (can't think of an easy way to do this). I only used speed control with the built in halls.

[NiHaoMike]

I wonder if it might be easier to spoof the accelrometers, they appear to be the chips marked "I4607 F75AA1".

[thm_w]

https://uploadcdn.oneyac.com/upload/document/1598939173087_1023.pdf

It would be a faster way to get a working device. But, then you have very limited flexibility (rpm, acceleration, etc.).
If you're determined to use the board, probably best to reverse engineer the whole thing.

Or, as mentioned: spend the $15 on a driver, or return it and get an already-reversed design.

[NiHaoMike]

Or, as mentioned: spend the $15 on a driver, or return it and get an already-reversed design.

Those $15 driver boards appear to use simple commutation logic rather than FOC if I understand them correctly, inferior to the original driver.

[bidrohini]

You can get more ideas from here:
https://medium.com/@alxm/converting-a-hoverboard-into-a-self-driving-mobile-robot-with-ros-d886c867e8a9

[thm_w]

Those $15 driver boards appear to use simple commutation logic rather than FOC if I understand them correctly, inferior to the original driver.

Yes, but if you don't need to go over ~500rpm or so its good enough.
The original driver is probably not FOC either, unless you install the modded FW.