The aim of this project was to drive a BLDC motor.

Background

I have been flying drone for along time and knew how to throw every thing together to get it all working, but never had I had the ability to finely control the speed of one of my props. I wanted to gain more knowledge of something we drone hobbyist take for granted.

The Project

I did a bit of research on how BLDC motor were driven and came to the conclusion that I needed the ESC (Electronic Speed Controller) that was in between my micro-controller and the motor. I was not willing to find the time to design and implement one. With that out of the way I looked up how to interface with one, specifically the one I had lying around.

My findings showed me that it used some sort of PWM (Pulse Width Modulation). There was some odd timing in the control, that being the Period is ever 20 milliseconds, 10% duty cycle was “off” and 20% was “full speed”. I thought that was simple enough, and went ahead and put my knowledge to the test.