I am trying to speed control a generic 12V 2 pin computer case fan (80mm x 80mm x 15mm).
I have purchased an Adafruit TB6612 1.2A DC/Stepper Motor Driver Breakout Board and a Raspberry Pi Zero W.
I have connected the fan, 12V source and TB6612 as this image, but I did not connect up PWMB, AIN2, BIN2 and STBY.
Using the code below, I can turn the fan on (source):
#!/usr/bin/env python
# Import required modules
import time
import RPi.GPIO as GPIO
# Declare the GPIO settings
GPIO.setmode(GPIO.BOARD)
# set up GPIO pins
GPIO.setup(7, GPIO.OUT) # Connected to PWMA
GPIO.setup(11, GPIO.OUT) # Connected to AIN2
GPIO.setup(12, GPIO.OUT) # Connected to AIN1
GPIO.setup(13, GPIO.OUT) # Connected to STBY
# Drive the motor clockwise
GPIO.output(12, GPIO.HIGH) # Set AIN1
GPIO.output(11, GPIO.LOW) # Set AIN2
# Set the motor speed
GPIO.output(7, GPIO.HIGH) # Set PWMA
# Disable STBY (standby)
GPIO.output(13, GPIO.HIGH)
# Wait 5 seconds
time.sleep(5)
# Drive the motor counterclockwise
GPIO.output(12, GPIO.LOW) # Set AIN1
GPIO.output(11, GPIO.HIGH) # Set AIN2
# Set the motor speed
GPIO.output(7, GPIO.HIGH) # Set PWMA
# Disable STBY (standby)
GPIO.output(13, GPIO.HIGH)
# Wait 5 seconds
time.sleep(5)
# Reset all the GPIO pins by setting them to LOW
GPIO.output(12, GPIO.LOW) # Set AIN1
GPIO.output(11, GPIO.LOW) # Set AIN2
GPIO.output(7, GPIO.LOW) # Set PWMA
GPIO.output(13, GPIO.LOW) # Set STBY
Problem
The above code only shows a 'HIGH' for PWMA
How to control the speed of the fan using the TB6612?