A lot has happened...

A project log for OpenBLDC

BLDC shield for arduino and stand alone controller

nerd.kingnerd.king 05/22/2017 at 12:170 Comments

So in the 2+ years since the last update a lot has happened.

My family expanded by additional boy this year and I am 2 years into my Master's of CS at Georgia Tech.

Children and school has drained almost all of my free time so OpenBLDC has been a tertiary goal. At the end of 2014 I purchased a hub motor off of alibaba and about a year later I purchased a second motor as well as two batteries and a battery charger. This motor will be a fundamental building block of OpenRover.

With the impending arrival of boy #2 this spring(2017), I took a semester off of school. The goal was to get the hub motors spinning so that I could submit an elective to build OpenRover over the summer. I was able to get two off the shelf motor controllers eval kits(Monolithic Power Systems EV6532). I spent January and February attempting to get the eval boards working with Hub motor. I hit one roadblock after another and was only able to get the wheels to move an inch before the controller would fault out. There was an ridiculous amount of noise on the circuit feeding back from the motor. I build isolation circuits and separate power regulators but gave up on these controllers.

My second attempt at off the shelf motor controllers were scooter controllers off of Alibaba. These were pretty low cost and I was able to get them in two weeks. I ordered three controllers so I could take one apart and evaluate the design. When I got the controllers they had about 7 pig tails on them, I could figured out power, motor and hall connectors but the company would not give me any documentation on the controllers.

So I took one of them apart and I was astounded my how simple the controller is. This design gave me some ideas on how to relayout my shield to handle the higher current(I pop traces on the original shield). Up late at night with my newborn, I was able to layout the new shield and submit them to dirtypcbs.

I have built one of the new shields and I hope to test it in the coming days. Additional Georgia Tech approve my elective and I was be building and modeling my rover over the summer with a Professor from France :) My hope is that I would be able to turn this project into a Master's thesis. I think I would be the first online student to do this.