Stepper Motor Speed Control using Arduino

Stepper Motor Speed Control using Arduino

• You can download the complete Arduino source code here by clicking on the button below.

Download Arduino Code

• Download .rar file, extract it and enjoy the complete source code.

Flow Chart

• I have made a flow chart so that you can easily understand the entire algorithm because sometimes it becomes difficult to understand the algorithm with the help of the source code.
• Flow chart for the Stepper Motor Speed Control using Arduino is shown in the figure below.

• First of all we need to start the serial port so that our communication could be started.
• Then there is a method to check the speed, if the speed is greater than the maximum speed of the stepper motor then the program will wait for the next command.
• If the stepper motor is not rotating with its maximum speed then we can increase its speed.
• Similarly if the minimum speed of the stepper motor is reached then the program will rotate for the next commands.
• If the minimum limit of the speed of the stepper motor is not reached then we have a option to reduce its further.
• At the end we should close the serial port so that exchange of unnecessary commands through the serial port could be avoided.

Block Diagram

• Block diagram will be helpful for use for the better understanding of the exchange of information.
• It tells us that how the information is exchanged sequentially among all the components used.
• Block diagram is shown in the figure below.

• Arduino UNO communicates with the L298 motor controller to control the speed of the stepper motor.
• L298 Motor controller manipulates the Arduino's commands and starts to control the speed of the stepper motor.

Arduino Code Description

• I have made two different functions for increasing (accelerating) the speed of the stepper motor and for decreasing (deaccelerating) the speed of the stepper motor respectively.
• I have declared a variable named as count.
• In Accelerate function, you have to send the command H  through the serial port to increase the speed of the stepper motor.
• In this function, I am continuously increasing the value of the count i.e as many times you send the command H the speed of the stepper motor will increase continuously.
• The source code of the Accelerate function is given below.

   void Accelerate_Motor()
   { 
    count=count+10; //Speed will increase continuously as we continue to press H
    if (count>120)  //Speed must not be greater than 120
    {
      count=120;
      }
    Serial.println("Accelerating"); //printing on the serial port
    Serial.println("");//prints blank line on the serial port
    myStepper.step(stepsPerRevolution);//counter clockwise rotation
    myStepper.setSpeed(count); //Updating the speed of the motor
    lcd.setCursor(3,0);//setting LCD cursor
    lcd.print("Acelerating"); //printing on LCD
   }

• In Deaccelerate function, you have to send the command L  through the serial port to increase the speed of the stepper motor.
• In this function, I am continuously reducing the value of the count i.e as many times you send the command L the speed of the stepper motor will reduce continuously.
• The source code of the Deaccelerate function is given below.

void Deaccelerate()
{
  count=count-10; //reducing the speed of the motor
  if (count<20) //speed of the motor must not be less than 20
  {
    count=20;
    }
  Serial.println("Deaccelerating"); // prints on the serial port
  Serial.println(""); //prints blank line on the serial port
  myStepper.step(stepsPerRevolution);
  myStepper.setSpeed(count); //Updating the speed of the motor
  lcd.setCursor(3,0);  //setting cursor on LCD
  lcd.print("Deaccelerating"); //prints the command on LCD
  }

• In the main source inside the loop I am calling both of these Accelerate and Deaccelerate functions.
• The executed commands will also be printed on the LCD (Liquid Crystal Diode).
• The main source code is given below.

#include <LiquidCrystal.h>//Library for LCD
#include <Stepper.h>     //Library for Stepper motor

const int stepsPerRevolution = 255;  

// initialize the stepper library on pins
Stepper myStepper(stepsPerRevolution, 4, 5, 6, 7);
char data;
int count = 120;
//LCD pins assigning
LiquidCrystal lcd(8, 9, 10, 11, 12, 13);
void setup() {
  // set the speed at 60 rpm
  myStepper.setSpeed(60);
  // initialize the serial port:
  Serial.begin(9600);// rate at which the arduino communicates

lcd.begin(20, 4);//LCD type

lcd.setCursor(3,0);//setting LCD cursor and printing on it
lcd.print("Stepper Motor");
lcd.setCursor(6,1);
lcd.print("Speed");
lcd.setCursor(5,2);
lcd.print("Control");
lcd.setCursor(2,3);
lcd.print("via Arduino UNO");

delay(3000);

lcd.clear ();//Clearing the LCD screen

lcd.setCursor(0,2);
lcd.print("www.TheEngineering");
lcd.setCursor(4,3);
lcd.print("Projects.com");
}

void loop() {
  if(Serial.available())
  {
    data = Serial.read(); //Reading the data from serial port
  }
  
    if(data == 'C'){Clockwise();}      //Clockwise rotation
    if(data == 'A'){AntiClockwise();} //Anti-clockwise rotation
    if(data == 'S')                  //stopping the stepper motor
    {
      data = 0; 
      lcd.setCursor(3,0);
      lcd.print("No rotation");
      Serial.println("No rotation");//print on the serial
      }   
     if(data == 'H'){Accelerate_Motor();}
     if(data == 'L'){Deaccelerate();}
}

Complete Hardware Setup

• In this section of the tutorial, I will show you the complete hardware setup that I have used for this project.
• Hardware consists of 12V power supply, Arduino UNO, L298 motor controller.
• When you upload the code to the Arduino board the system will look like the figure shown below.

• When you press H to increase the speed of the stepper motor, the statement accelerating will be printed on the LCD.
• The printed executed command is printed on the LCD and is shown in the figure below.

• When you press L to reduce the speed of the stepper motor, the statement Deaccelerating will be printed on the LCD.
• The printed executed command is printed on the LCD and is shown in the figure below.