Hello,
I just got a BLDC motor but I am not sure how to wire it to my Arduino. Here are some (very basics) questions:
Thanks for your help.
There are a few ways to drive a brushless motor. The important thing is that in order to turn on the 3 phase bridge in the correct sequence and timing (commutate) the controller has to know the position of the rotor.
Hall effect sensors are one way of providing this rotor feedback. They have an advantage of giving rotor posistion even when the motor is not in motion, this allows for full power startup and low rpm control. They also need minimal processing power on the microcontroller to switch the bridge based on the hall inputs.
Then there are sensoreless methods using either back emf voltage from the rotating motor or vector based control using current sense to determine rotor position. These require considerably more processing power.
You can buy an electronic speed controller (esc) that can be either sensoreless or sensored and they would have the microcontroller onboard to run the motor, they just need a servo signal from the arduino.
If you want to control the bridge directly with the arduino then you would have to make ( tricky ) or buy a 3 half bridge power section and switch depending on the hall inputs. The "speed control" in the second diagram is just potentiometer.
Might be a place to start:
(although they are trying to sell you their chips of course!)
This might be better, its for AVRs and sinusoidal drive is covered Application Notes | Microchip Technology
Hello Alka & MarkT,
Very useful information! Thank you. I will buy a sensored ESC on the web. Any recommendation? Brand or model?
My motor rated current is 6.4 amps and peak current is 19 amps.
Commodity RC ESCs don't come with good datasheets, if at all, I'm afraid, but they are very cheap so you
get a chance to try a smallish one first and if its not upto the job upgrade. You need to figure out if each ESC
gives the control you want (it should be able to reverse and go slowly if its sensored, but that's not guaranteed,
these devices are sold for one purpose, powering RC models).
Hello,
I've been trying to find a sensored ECS for the past couple weeks but I am not sure what to buy. Can someone recommend a good website?
I thought buying one of those:
I need to be able to reverse the rotation of the motor and control the speed.
That's a whole page full ESCs and they all appear to be sensorless. Most are aircraft/multirotor ESCs so will not have a reverse function.
You probably want to look for a car ESC. HobbyKing certainly has several sensored ESCs with reverse e.g. https://hobbyking.com/en_us/hobbykingr-tm-35a-sensored-sensorless-car-esc-1-10-1-12.html
But exactly what sensored brushless motor do you want to drive ? They are not all compatible with all ESCs.
Steve
They don't come with documents! They are high current sensorless BLDC drivers, typically using
back-EMF rotor position sensing. Textbooks/appliction notes on motor control explain the way
BLDCs are typically driven (trapezoidal with PWM).
I have done to control BLDC motor of Hoverboard,
with BLDC-8015A: http://www.wantmotor.com/product/8015a.html
Please check my github for more informations:
Thank you
Hello,
What is the purpose of the Hall sensors?
Maybe it will help :
Advantages of Brushless DC motor
Brushless DC motor does not have any carbon brushes, which reduces frequent replacement requirements of brushes and maintenance costs.
Disadvantages of Brushless DC motor
The cost of a brushless DC motor is comparatively higher as compared to brushed DC motor and the electronic controller also increases the cost of overall setup, as in a traditional motor, low-cost mechanical commutation setup involving brushes is used.
