5.4.13 Project 7.1 Control the Fan

1. Description

In this project, we will learn how to make a small fan.

2. Component Knowledge

The small fan uses a 130 DC motor and safe fan blades. You can use PWM output to control the fan speed.

3. Control Method

Two pins are required to control the motor of the fan, one for INA and two for INB. The PWM value range is 0~255. When the PWM output of the two pins is different, the fan can rotate.

INA - INB <= -45	Rotate clockwise
INA - INB >= 45	Rotate anticlockwise
INA == 0, INB == 0	Stop

4. Control Pins

INA	19
INB	18

5. Test Code

#define fanPin1 19
#define fanPin2 18

void setup() {
  pinMode(fanPin1, OUTPUT);
  pinMode(fanPin2, OUTPUT);
}

void loop() {
  digitalWrite(fanPin1, LOW); //pwm = 0
  analogWrite(fanPin2, 180);
  delay(3000);
  digitalWrite(fanPin1, LOW);
  digitalWrite(fanPin2, LOW);
  delay(1000);
  digitalWrite(fanPin1, HIGH); //pwm = 255
  analogWrite(fanPin2, 210);
  delay(3000);
  digitalWrite(fanPin1, LOW);
  digitalWrite(fanPin2, LOW);
  delay(1000);

}

6. Test Result

The fan will rotate clockwise and anticlockwise at different speeds.