Project 7: Fan

Description

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

Component Knowledge

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

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

Control Pins

INA	19
INB	18

Project 7.1 Fan

We can control the anticlockwise and clockwise rotation speed of the fan.

Test Code

from machine import Pin,PWM
import time
#Two pins of the motor
INA =PWM(Pin(19,Pin.OUT),10000)#INA corresponds to IN+
INB =PWM(Pin(18,Pin.OUT),10000)#INB corresponds to IN-

try:
    while True:
        #Counterclockwise 2s
        INA.duty(0) #The range of duty cycle is 0-1023
        INB.duty(700)
        time.sleep(2)
        #stop 1s
        INA.duty(0)
        INB.duty(0)
        time.sleep(1)
        #Turn clockwise for 2s
        INA.duty(600)
        INB.duty(0)
        time.sleep(2)
        #stop 1s
        INA.duty(0)
        INB.duty(0)
        time.sleep(1)
except:
    INA.duty(0)
    INB.duty(0)
    INA.deinit()
    INB.deinit()

Test Result

The fan will rotate clockwise and anticlockwise at different speeds.

Project 7.2 Button Control Fan

Button one controls the fan switch.

Test Code

from machine import Pin,PWM
import time
#Two pins of the motor
INA =PWM(Pin(19,Pin.OUT),10000)#INA corresponds to IN+
INB =PWM(Pin(18,Pin.OUT),10000)#INB corresponds to IN-
button1 = Pin(16, Pin.IN, Pin.PULL_UP)
count = 0

try:
    while True:
        btnVal1 = button1.value()  # Reads the value of button 1
        if(btnVal1 == 0):
            time.sleep(0.01)
            while(btnVal1 == 0):
                btnVal1 = button1.value()
                if(btnVal1 == 1):
                    count=count + 1
                    print(count)
        val = count % 2
        if(val == 1):
            INA.duty(0) #The range of duty cycle is 0-1023
            INB.duty(700)
        else:
            INA.duty(0)
            INB.duty(0)
except:
    INA.duty(0)
    INB.duty(0)
    INA.deinit()
    INB.deinit()

Test Result

Click button 1, the fan starts to rotate, the press the button 1 again, the fan stops.