YAP - YABR (Yet Another Balancing Robot)


Welcome to another YAP (Yet Another Project)
This time it’s a self balancing robot…
I was researching STM32 stuff (blame @Jarrett) and stumbled onto an interesting site…


While not STM32 based the balancing robot caught my interest mainly cuz I had a bunch of the needed parts gathering dust… So I decided to build one and figured I’d document the process here.

The one thing I did not have was the wheels. In the project he is using laser cut plywood to make them but I sort of wanted something better. I spent a lot of time searching AliExpress. I wanted a similar size (2ish inches) but with decent rubber… I also had to find something that would easily mount on the 5mm stepper shafts. While not really as cheap as I’d like I found these and ordered a set:

Since I had to wait for the wheels I went about gathering the parts I did have and figuring out what size board I would need.

Looks like a 7cm x 9cm proto will do the trick and luckily I had one.

One thing I was missing was the radio transceiver module. Looked around and ordered a couple of these as I had seen them used in some other projects:

Next I thought about the frame. They used plywood for the prototype but I didn’t have any thin stuff to use. But I do have lots of aluminum angle so I decided to use it. I’m wondering if it will affect the rf signal but it will just be a frame so there will be lots of open area.


Normally I would use a NANO for something like this but the PRO-MINI is even smaller (cuz it doesn’t have the USB/Serial chip onboard) and since I had one I decide to go with it as the NANO was a bit too large. The caveat is that you need a USB/Serial adapter to program but the programming pins can stick straight from the board allowing and easier connection…
And the CH340 USB/Serial board are really cheap…
And I shouldn’t have to make many programming changes…


I decided to use a drawing program to figure out the best sizes for the aluminum. I figured better measure twice and cut once (though typically I do the complete opposite…

I’m going to use 1/16" x 1" angle. Tomorrow I will cut it to size and drill out the holes to mount the steppers. I’ll probably just pop rivet the pieces together to make the frame.


Here is the stepper motor(s) I’m going to use:

It’s a NEMA17 instead of the smaller NEMA14 used in the prototype but they should work…
Mebbe I’ll need a bigger battery…


So I cut up some aluminum angle

Used a square to align and drilled some holes:

Notched out where I want to mount the steppers:

Finished it up with a file:

Put it together with pop rivets:

And the final product:


I got the wheels today and am pretty happy with them

They come with a heavy duty adapter to mount on the 5mm stepper shaft with 2 set screws

The wheel then mounts over the adapter and locks in with a screw and lock washer

They are a bit larger diameter (2.5" rather than 2") than used in prototype but it should not be an issue…
I don’t think…


Mounted the PCB on the frame and attached the motors…

Next on to wiring up the circuit board… While normally I’d use sockets for the various modules I think I’ll solder them in place to keep a low profile (the sockets add 5/16" to the height)…

And hope I don’t need to replace any of them…


Very nice progress reports!

Hey, is that a TTY in the background?


Yup… Found it in the trash… Seems to work…