Control a brushless motor with a Raspberry Pi Zero

Overview

I had a little thought, so I tried to control a commercially available brushless motor using RPi Zero.

Constitution

Raspberry Pi Zero W (https://www.amazon.co.jp/gp/product/B0799FCCWS/)
Suitable brushless motor and ESC (speed controller) set (Reference: https://www.amazon.co.jp/gp/product/B01MTCBO7D/)
Suitable battery

Connect

Connect the motor and ESC. There are 3 lines, but even if you connect them properly, the rotation will only be reversed, so it's okay.
Connect ESC and RPi. There are three in the connector, but the middle wire is not used. Use another one of some color on the opposite side of the black line. Connect the black one to the appropriate GND and the colored one to the appropriate GPIO. GPIO will be specified later in the program, so make a note of the number. Pin assignment Reference: https://www.raspberrypi.org/documentation/usage/gpio/
Connect the battery at the stage of checking the operation. I don't know what will happen, so a safe battery is recommended. In the example, we used the eel-shaped LiFe that was lying around. Please note that eels are not usually rolled.

programming

For the time being, specify the pulse width and repeat turning it little by little.

Sample source code

import pigpio
import time
motor_pin = 27 #Noted GPIO number

pi = pigpio.pi()

for i in range(3):
        pi.set_servo_pulsewidth(motor_pin, 1500) 
        time.sleep(1)
        pi.set_servo_pulsewidth(motor_pin, 1600) 
        time.sleep(1)
        pi.set_servo_pulsewidth(motor_pin, 1700) 
        time.sleep(1)
        pi.set_servo_pulsewidth(motor_pin, 1800) 
        time.sleep(1)
        pi.set_servo_pulsewidth(motor_pin, 1900) 
        time.sleep(1)
        pi.set_servo_pulsewidth(motor_pin, 2000) 
        time.sleep(1)
        

pi.set_servo_pulsewidth(motor_pin, 0) 
pi.stop()

Commentary

pi.set_servo_pulsewidth(motor_pin, 1500) 
time.sleep(1)

Specify the GPIO number with motor_pin and specify the pulse width numerically. The range of values that can be specified depends on the ESC specifications. If you don't know the ESC specifications, you have to fumble around. In this ESC, it was possible to specify from about 1500 to about 2000. In sleep, specify the duration until the next state.

pi.set_servo_pulsewidth(motor_pin, 0)

If you want to stop it, I feel that it wouldn't work unless you wrote something like this. Maybe I didn't need it. Well, it's magical.

It seems that some ESCs need magic before moving. It has no choice but to check the ESC specifications.

Summary

With that feeling, I was able to control the brushless motor very easily. However, it may not be a strict brushless motor control because it uses the existing ESC to control the pulse and time. Originally, I want to control the ESC function itself with RPi.

By the way, this brushless motor does not rotate the contents, but the outer gawa rotates, so if you do not fix it, it will go wild (laugh) I think it is safer to use a motor that rotates the central rotor.

If you use RPi to control the motor, you can control it visibly! !! It gives you a sense of accomplishment, so it is also recommended for studying programming. You can buy this brushless motor and ESC set for about 1000 yen, so I think you can enjoy it at a lower price than buying a poor electronic work kit.

Control brushless motors with GPIOs on Raspberry Pi Zero