Circuit Diagram:

Code:

#include <Servo.h>

int servoPin = 9; int servoPos = 45;

int servoInitalPos = 180;

Servo myServo;

void setup()

{

myServo.attach(servoPin);

}

void loop()

{

int pos = 0;int dtwait=15;

for(pos = 0; pos < 180; pos += 1) {myServo.write(pos);

delay(dtwait);

}

for(pos = 180; pos>=1; pos -= 1) {myServo.write(pos);

delay(dtwait);

}

}

Output:

Program 4.2: To interface servo motor, Photo resistor (LDR) with Arduino and write a program tosweep a servo back and forth through its full range of motion depending on light.

Component:

Circuit Diagram:

Code:

#include <Servo.h>

int servoPin = 6;int servoPos = 0;int red = 8;

int green = 9;int yellow = 10;Servo myServo;

void setup()

{

pinMode(red, OUTPUT);pinMode(green, OUTPUT);pinMode(yellow, OUTPUT);myServo.attach(servoPin);Serial.begin(9600);

}

void loop()

{

Serial.println(analogRead(A1));Serial.println(analogRead(A1));

if (analogRead(A1) <= 700 && analogRead(A1) >595){digitalWrite(red, HIGH);

digitalWrite(green, LOW);digitalWrite(yellow, LOW);myServo.write(180);

}

else if (analogRead(A1) <= 595 && analogRead(A1) > 200){

digitalWrite(red, LOW);digitalWrite(green, HIGH);digitalWrite(yellow, LOW);myServo.write(90);

}

else{

digitalWrite(red, LOW);digitalWrite(green, LOW);digitalWrite(yellow, HIGH);myServo.write(0);

}

}

Output:

Program 4.3: Write a program to control two DC motors with Arduino.

Component:

Theory:

DC Motor:

A direct current (DC) motor is a type of electric machine that converts electrical energy into mechanical energy. DC motors take electrical power through direct current, and convert this energy into mechanical rotation.

DC motors use magnetic fields that occur from the electrical currents generated, which powers the movement of a rotor fixed within the output shaft. The output torque and speed depend upon both the electrical input and the design of the motor.

Circuit Diagram:

Code:

int speedPin = 11;int speedPin2 = 3;int dir1= 9;

int dir2= 10;

int dir3= 5;

int dir4= 6;

void setup()

{

pinMode(speedPin, OUTPUT);pinMode(speedPin2, OUTPUT);pinMode(dir1, OUTPUT);pinMode(dir2, OUTPUT);pinMode(dir3, OUTPUT);pinMode(dir4, OUTPUT);

}

void loop()

{

digitalWrite(dir1, HIGH);digitalWrite(dir2, LOW);digitalWrite(dir3, LOW);digitalWrite(dir4, HIGH);analogWrite(speedPin,100);analogWrite(speedPin2,100);

}

Output:

Program 4.4: To interface IR remote with Arduino Write a program to create useful commands fromthe IR remote control.

Component: Arduino Uno, IR Sensor

Theory:

(InfraRed remote control) A handheld, wireless device used to operate audio, video and other electronic equipment within a room using light signals in the infrared (IR) range.

Infrared light requires line of sight to its destination. Low-end remotes use only one transmitter at the end of the unit and have to be aimed directly at the equipment.

High-quality remotes have three or four powerful IR transmitters set at different angles to shower the room with signals.

Circuit Diagram:

Code:

#include <IRremote.h>

int IRpin = A0; IRrecv IR(IRpin);

decode_results res;

void setup()

{

Serial.begin(9600);IR.enableIRIn();

IR.blink13(true);

}

void loop()

{

while(IR.decode(&res) == 0){

}

IR.resume();

if (res.value == 0xFD08F7){Serial.print(“Hex Value: ”);Serial.println(res.value,HEX);

}

else if (res.value == 0xFD8877){Serial.print(“Hex Value: ”);Serial.println(res.value,HEX);

}

else if (res.value == 0xFD48B7){Serial.print(“Hex Value: ”);Serial.println(res.value,HEX);

}

}

Output:

Program 4.5: To interface RGB led and IR remote, write a program to control RGB led with IRremote.

Component:

Circuit Diagram:

Code:

#include <IRremote.h>

int IRpin = A0;IRrecv IR(IRpin);

decode_results res;int red = 12;

int blue = 11;int green = 10;

void setup()

{

Serial.begin(9600);IR.enableIRIn();

IR.blink13(true);pinMode(red, OUTPUT);pinMode(blue, OUTPUT);pinMode(green, OUTPUT);

}

void loop()

{

while(IR.decode(&res) == 0){

}

//Serial.println(res.value);

//Serial.print(“Hex Value: ”);Serial.println(res.value,HEX);IR.resume();

if (res.value == 0xFD08F7){digitalWrite(red, HIGH);

digitalWrite(blue, LOW);digitalWrite(green, LOW);

}

else if (res.value == 0xFD8877){digitalWrite(red, LOW);digitalWrite(blue, HIGH);digitalWrite(green, LOW);

}

else if (res.value == 0xFD48B7){digitalWrite(red, LOW);digitalWrite(blue, LOW);digitalWrite(green, HIGH);

}}

Output:

Exercise: Write a program to control DC motor speed with an IR remote