Infared Remote

Infared

Infrared radiation is a form of light similar to the light we see all around us. The only difference between IR light and visible light is the frequency and wavelength. Infrared radiation lies outside the range of visible light, so humans can’t see it:
Because IR is a type of light, IR communication requires a direct line of sight from the receiver to the transmitter. It can’t transmit through walls or other materials like WiFi or Bluetooth.

Connect IR Receiver to Arduino

https://roboticsbackend.com/arduino-ir-remote-controller-tutorial-setup-and-map-buttons/

• Make sure IRremote library is installed (library)

infared_remote_codes.ino

infared_remote_codes.ino

• View simulation

#include <IRremote.h>
 
const int RECV_PIN = 7;
 
void setup()
{
    Serial.begin(9600);
    IrReceiver.begin(RECV_PIN, ENABLE_LED_FEEDBACK); // Start the receiver
}
 
void loop()
{
    if (IrReceiver.decode()) // Check if a signal is received
    {
        // Serial.println(IrReceiver.decodedIRData.decodedRawData, HEX); // Print the received data in HEX
        Serial.println(IrReceiver.decodedIRData.command);
        IrReceiver.resume(); // Prepare for the next value
    }
}

• View output from the serial monitor

70
64
64
21
21

IRremote_map.ino

Map each button to a number

IRremote_map.ino

#include <IRremote.h>
 
#define IR_RECEIVE_PIN 7
 
#define IR_BUTTON_1 12
#define IR_BUTTON_2 24
#define IR_BUTTON_3 94
#define IR_BUTTON_PLAY_PAUSE 64
 
#define IR_BUTTON_POWER 69        // Power button
#define IR_BUTTON_REWIND 68       // Rewind button
#define IR_BUTTON_FAST_FORWARD 67 // Fast-forward button
#define IR_BUTTON_VOLUME_UP 70    // Volume Up
#define IR_BUTTON_VOLUME_DOWN 21  // Volume Down
 
void setup()
{
    Serial.begin(9600);
    IrReceiver.begin(IR_RECEIVE_PIN);
}
 
void loop()
{
    if (IrReceiver.decode())
    {
        IrReceiver.resume();
        int command = IrReceiver.decodedIRData.command;
 
        // Handle the received IR command
        switch (command)
        {
        case IR_BUTTON_1:
            Serial.println("Pressed on button 1");
            break;
        case IR_BUTTON_2:
            Serial.println("Pressed on button 2");
            break;
        case IR_BUTTON_3:
            Serial.println("Pressed on button 3");
            break;
        case IR_BUTTON_PLAY_PAUSE:
            Serial.println("Pressed on button Play/Pause");
            break;
        case IR_BUTTON_POWER:
            Serial.println("Pressed on button Power");
            break;
        case IR_BUTTON_REWIND:
            Serial.println("Pressed on button Rewind");
            break;
        case IR_BUTTON_FAST_FORWARD:
            Serial.println("Pressed on button Fast Forward");
            break;
        case IR_BUTTON_VOLUME_UP:
            Serial.println("Pressed on button Volume Up");
            break;
        case IR_BUTTON_VOLUME_DOWN:
            Serial.println("Pressed on button Volume Down");
            break;
        default:
            Serial.print("Unknown button code received: ");
            Serial.println(command);
            break;
        }
    }
}

Arduino IR Robot

https://www.tinkercad.com/things/38tyb8Jv6m3-arduino-ir-robot

• See L293D Motor Driver

PWM

PWM (Pulse Width Modulation)

A PWM (Pulse Width Modulation) is basically a way to get a specific voltage (ex: 4.1V) with only HIGH/LOW (5V/0V) states. The PWM creates a pulse running at a given frequency – 500Hz for Arduino Uno. Then, a duty cycle parameter will tell what percentage of each pulse is in the HIGH state or LOW state.

The frequent change of HIGH/LOW states produces an average voltage output. For example, at a 50% duty cycle (50% of the time HIGH, 50% of the time LOW), the output voltage would be 2.5V.

PWM pins

You can use the PWM only on some digital pins, which have a “~” next to their number. The Arduino Uno pins compatible with PWM are the pins 3, 5, 6, 9, 10 and 11. So you have 6 pins where you can create a PWM, using the analogWrite() function.

Secrets of Arduino PWM

PWM and Timer Pin Mapping for Atmega328P

https://docs.simplefoc.com/choosing_pwm_pins

Timer	Pins	Other Info
TIM0	5, 6	millis()
TIM1	9, 10
TIM2	3, 11	IRremote

• See Arduino Uno PWM pins conflict

Ir reciever not working after motor starts

PWM on Pin 3 is generated by Timer2. IRremote, by default, uses Timer2 for timing. There is your conflict.

To fix it, move enA to a PWM pin that is not 3 or 11 (Timer2). The safest solution is to move them both to Pins 5 and 6 (Timer0). Timer0 is the millis() timer so it is unlikely that any future addition will cause a new timer conflict.

L293D_IRremote.ino

• See simulation

L293D_IRremote.ino

#include <Arduino.h>
 
// PIN VARIABLES
/***IRremote variables*************************************************************************/
#include <IRremote.h>
 
#define IR_RECEIVE_PIN 11
 
#define IR_BUTTON_1 12
#define IR_BUTTON_2 24
#define IR_BUTTON_3 94
#define IR_BUTTON_PLAY_PAUSE 64
#define IR_BUTTON_POWER 69        // Power button
#define IR_BUTTON_REWIND 68       // Rewind button
#define IR_BUTTON_FAST_FORWARD 67 // Fast-forward button
#define IR_BUTTON_VOLUME_UP 70    // Volume Up
#define IR_BUTTON_VOLUME_DOWN 21  // Volume Down
 
/***Motor Driver variables*************************************************************************/
// TB6612FNG Motor Driver
// the right motor will be controlled by the motor A pins on the motor driver
const int PWMA = 5; // speed control pin on the motor driver for the right motor
const int AIN1 = 2; // control pin 1 on the motor driver for the right motor
const int AIN2 = 3; // control pin 2 on the motor driver for the right motor
 
// the left motor will be controlled by the motor B pins on the motor driver
const int PWMB = 6; // speed control pin on the motor driver for the left motor
const int BIN1 = 8; // control pin 1 on the motor driver for the left motor
const int BIN2 = 9; // control pin 2 on the motor driver for the left motor
 
// L293D mapping
const int IN1_M1 = AIN1; // Control pin 1 for the right motor (Motor A)
const int IN2_M1 = AIN2; // Control pin 2 for the right motor (Motor A)
const int PWM_M1 = PWMA; // Speed control for the right motor (Motor A)
 
const int IN1_M2 = BIN1; // Control pin 1 for the left motor (Motor B)
const int IN2_M2 = BIN2; // Control pin 2 for the left motor (Motor B)
const int PWM_M2 = PWMB; // Speed control for the left motor (Motor B)
int speed = 150;
 
// VARIABLES
int motorSpeed = 0; // starting speed for the motor
 
// Function declarations
void forward();
void backward();
void turnLeft();
void turnRight();
void stop();
void speedUp();
void speedDown();
// Extra
void rightMotor(int speed);
void leftMotor(int speed);
 
void setup()
{
    // set the motor control pins as outputs
    pinMode(AIN1, OUTPUT);
    pinMode(AIN2, OUTPUT);
    pinMode(PWMA, OUTPUT);
 
    pinMode(BIN1, OUTPUT);
    pinMode(BIN2, OUTPUT);
    pinMode(PWMB, OUTPUT);
 
    Serial.begin(115200);                      // begin serial communication with the computer
    Serial.println("To infinity and beyond!"); // test the serial connection
    Serial.print("Motor Speed: ");             // print the speed that the motor is set to run at
    Serial.println(speed);
 
    IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);
}
 
void loop()
{
    if (IrReceiver.decode())
    {
        int command = IrReceiver.decodedIRData.command;
        Serial.println(command);
 
        // Handle the received IR command
        switch (command)
        {
        case IR_BUTTON_1:
            Serial.println("Pressed on button 1");
            speedDown();
            break;
        case IR_BUTTON_2:
            Serial.println("Pressed on button 2");
            speedUp();
            break;
        case IR_BUTTON_3:
            Serial.println("Pressed on button 3");
            break;
        case IR_BUTTON_PLAY_PAUSE:
            Serial.println("Pressed on button Play/Pause");
            stop();
            break;
        case IR_BUTTON_POWER:
            Serial.println("Pressed on button Power");
            break;
        case IR_BUTTON_REWIND:
            Serial.println("Pressed on button Rewind");
            turnLeft();
            break;
        case IR_BUTTON_FAST_FORWARD:
            Serial.println("Pressed on button Fast Forward");
            turnRight();
            break;
        case IR_BUTTON_VOLUME_UP:
            Serial.println("Pressed on button Volume Up");
            forward();
            break;
        case IR_BUTTON_VOLUME_DOWN:
            Serial.println("Pressed on button Volume Down");
            backward();
            break;
        default:
            Serial.print("Unknown button code received: ");
            Serial.println(command);
            break;
        }
 
        IrReceiver.resume(); // Prepare for the next IR signal
    }
}
 
// Motor control functions
void forward()
{
    Serial.println("forward");
    // analogWrite(PWM_M1, speed);
    // analogWrite(PWM_M2, speed);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
    leftMotor(speed);
    rightMotor(speed);
}
 
void backward()
{
    Serial.println("backward");
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
    digitalWrite(IN1_M1, LOW);
    digitalWrite(IN2_M1, HIGH);
    digitalWrite(IN1_M2, LOW);
    digitalWrite(IN2_M2, HIGH);
 
    // back up
    // rightMotor(-255);
    // leftMotor(-255);
}
 
void turnLeft()
{
    Serial.println("turnLeft");
    // analogWrite(PWM_M1, 0);
    // analogWrite(PWM_M2, speed);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
 
    // Temp workaround
    leftMotor(-speed);
    rightMotor(speed);
}
 
void turnRight()
{
    Serial.println("turnRight");
    // analogWrite(PWM_M1, speed);
    // analogWrite(PWM_M2, 0);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
 
    // Temp workaround
    leftMotor(speed);
    rightMotor(-speed);
}
 
void stop()
{
    Serial.println("stop");
    //    digitalWrite(IN1_M1, LOW);
    //    digitalWrite(IN2_M1, LOW);
    //    digitalWrite(IN1_M2, LOW);
    //    digitalWrite(IN2_M2, LOW);
 
    rightMotor(0);
    leftMotor(0);
}
 
void speedUp()
{
    Serial.println("speedUp");
    speed += 10;
    if (speed > 255)
        speed = 255;
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
}
 
void speedDown()
{
    Serial.println("speedDown");
    speed -= 10;
    if (speed < 0)
        speed = 0;
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
}
 
/********************************************************************************/
void leftMotor(int motorSpeed) // function for driving the left motor
{
    if (motorSpeed > 0) // if the motor should drive forward (positive speed)
    {
        digitalWrite(BIN1, HIGH); // set pin 1 to high
        digitalWrite(BIN2, LOW);  // set pin 2 to low
    }
    else if (motorSpeed < 0) // if the motor should drive backward (negative speed)
    {
        digitalWrite(BIN1, LOW);  // set pin 1 to low
        digitalWrite(BIN2, HIGH); // set pin 2 to high
    }
    else // if the motor should stop
    {
        digitalWrite(BIN1, LOW); // set pin 1 to low
        digitalWrite(BIN2, LOW); // set pin 2 to low
    }
    analogWrite(PWMB, abs(motorSpeed)); // now that the motor direction is set, drive it at the entered speed
}
 
/********************************************************************************/
void rightMotor(int motorSpeed) // function for driving the right motor
{
    if (motorSpeed > 0) // if the motor should drive forward (positive speed)
    {
        digitalWrite(AIN1, HIGH); // set pin 1 to high
        digitalWrite(AIN2, LOW);  // set pin 2 to low
    }
    else if (motorSpeed < 0) // if the motor should drive backward (negative speed)
    {
        digitalWrite(AIN1, LOW);  // set pin 1 to low
        digitalWrite(AIN2, HIGH); // set pin 2 to high
    }
    else // if the motor should stop
    {
        digitalWrite(AIN1, LOW); // set pin 1 to low
        digitalWrite(AIN2, LOW); // set pin 2 to low
    }
    analogWrite(PWMA, abs(motorSpeed)); // now that the motor direction is set, drive it at the entered speed
}

L293D_IRremote_e-stop.ino

• See simulation

L293D_IRremote_e-stop.ino

#include <Arduino.h>
 
// PIN VARIABLES
int buttonPin = 7;
int buttonState = 0;
int LED_PIN = 13;
 
/***IRremote variables*************************************************************************/
#include <IRremote.h>
 
#define IR_RECEIVE_PIN 11
 
#define IR_BUTTON_1 12
#define IR_BUTTON_2 24
#define IR_BUTTON_3 94
#define IR_BUTTON_PLAY_PAUSE 64
#define IR_BUTTON_POWER 69        // Power button
#define IR_BUTTON_REWIND 68       // Rewind button
#define IR_BUTTON_FAST_FORWARD 67 // Fast-forward button
#define IR_BUTTON_VOLUME_UP 70    // Volume Up
#define IR_BUTTON_VOLUME_DOWN 21  // Volume Down
 
/***Motor Driver variables*************************************************************************/
// TB6612FNG Motor Driver
// the right motor will be controlled by the motor A pins on the motor driver
const int PWMA = 5; // speed control pin on the motor driver for the right motor
const int AIN1 = 2; // control pin 1 on the motor driver for the right motor
const int AIN2 = 3; // control pin 2 on the motor driver for the right motor
 
// the left motor will be controlled by the motor B pins on the motor driver
const int PWMB = 6; // speed control pin on the motor driver for the left motor
const int BIN1 = 8; // control pin 1 on the motor driver for the left motor
const int BIN2 = 9; // control pin 2 on the motor driver for the left motor
 
// L293D mapping
const int IN1_M1 = AIN1; // Control pin 1 for the right motor (Motor A)
const int IN2_M1 = AIN2; // Control pin 2 for the right motor (Motor A)
const int PWM_M1 = PWMA; // Speed control for the right motor (Motor A)
 
const int IN1_M2 = BIN1; // Control pin 1 for the left motor (Motor B)
const int IN2_M2 = BIN2; // Control pin 2 for the left motor (Motor B)
const int PWM_M2 = PWMB; // Speed control for the left motor (Motor B)
int speed = 150;
 
// VARIABLES
int motorSpeed = 0; // starting speed for the motor
 
// Function declarations
void forward();
void backward();
void turnLeft();
void turnRight();
void stop();
void speedUp();
void speedDown();
// Extra
void rightMotor(int speed);
void leftMotor(int speed);
 
void setup()
{
    // set the motor control pins as outputs
    pinMode(AIN1, OUTPUT);
    pinMode(AIN2, OUTPUT);
    pinMode(PWMA, OUTPUT);
 
    pinMode(BIN1, OUTPUT);
    pinMode(BIN2, OUTPUT);
    pinMode(PWMB, OUTPUT);
 
    Serial.begin(115200);                      // begin serial communication with the computer
    Serial.println("To infinity and beyond!"); // test the serial connection
    Serial.print("Motor Speed: ");             // print the speed that the motor is set to run at
    Serial.println(speed);
 
    IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);
 
    pinMode(buttonPin, INPUT_PULLUP); // set this as a pullup to sense whether the switch is flipped
}
 
void loop()
{
    if (IrReceiver.decode())
    {
        int command = IrReceiver.decodedIRData.command;
        Serial.println(command);
 
        // Handle the received IR command
        switch (command)
        {
        case IR_BUTTON_1:
            Serial.println("Pressed on button 1");
            speedDown();
            break;
        case IR_BUTTON_2:
            Serial.println("Pressed on button 2");
            speedUp();
            break;
        case IR_BUTTON_3:
            Serial.println("Pressed on button 3");
            break;
        case IR_BUTTON_PLAY_PAUSE:
            Serial.println("Pressed on button Play/Pause");
            stop();
            break;
        case IR_BUTTON_POWER:
            Serial.println("Pressed on button Power");
            break;
        case IR_BUTTON_REWIND:
            Serial.println("Pressed on button Rewind");
            turnLeft();
            break;
        case IR_BUTTON_FAST_FORWARD:
            Serial.println("Pressed on button Fast Forward");
            turnRight();
            break;
        case IR_BUTTON_VOLUME_UP:
            Serial.println("Pressed on button Volume Up");
            forward();
            break;
        case IR_BUTTON_VOLUME_DOWN:
            Serial.println("Pressed on button Volume Down");
            backward();
            break;
        default:
            Serial.print("Unknown button code received: ");
            Serial.println(command);
            break;
        }
 
        IrReceiver.resume(); // Prepare for the next IR signal
    }
 
    // "E-stop" button
    const int debounceDelay = 50; // 50ms debounce
    static unsigned long lastDebounceTime = 0;
    static int lastButtonState = HIGH;
    int currentState = digitalRead(buttonPin);
    if (currentState != lastButtonState)
    {
        lastDebounceTime = millis();
    }
    if ((millis() - lastDebounceTime) > debounceDelay)
    {
        if (currentState == LOW)
        {
            stop();
            digitalWrite(LED_PIN, HIGH);
        }
    }
    lastButtonState = currentState;
}
 
// Motor control functions
void forward()
{
    Serial.println("forward");
    // analogWrite(PWM_M1, speed);
    // analogWrite(PWM_M2, speed);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
    leftMotor(speed);
    rightMotor(speed);
}
 
void backward()
{
    Serial.println("backward");
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
    digitalWrite(IN1_M1, LOW);
    digitalWrite(IN2_M1, HIGH);
    digitalWrite(IN1_M2, LOW);
    digitalWrite(IN2_M2, HIGH);
 
    // back up
    // rightMotor(-255);
    // leftMotor(-255);
}
 
void turnLeft()
{
    Serial.println("turnLeft");
    // analogWrite(PWM_M1, 0);
    // analogWrite(PWM_M2, speed);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
 
    // Temp workaround
    leftMotor(-speed);
    rightMotor(speed);
}
 
void turnRight()
{
    Serial.println("turnRight");
    // analogWrite(PWM_M1, speed);
    // analogWrite(PWM_M2, 0);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
 
    // Temp workaround
    leftMotor(speed);
    rightMotor(-speed);
}
 
void stop()
{
    Serial.println("stop");
    //    digitalWrite(IN1_M1, LOW);
    //    digitalWrite(IN2_M1, LOW);
    //    digitalWrite(IN1_M2, LOW);
    //    digitalWrite(IN2_M2, LOW);
 
    rightMotor(0);
    leftMotor(0);
}
 
void speedUp()
{
    Serial.println("speedUp");
    speed += 10;
    if (speed > 255)
        speed = 255;
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
}
 
void speedDown()
{
    Serial.println("speedDown");
    speed -= 10;
    if (speed < 0)
        speed = 0;
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
}
 
/********************************************************************************/
void leftMotor(int motorSpeed) // function for driving the left motor
{
    if (motorSpeed > 0) // if the motor should drive forward (positive speed)
    {
        digitalWrite(BIN1, HIGH); // set pin 1 to high
        digitalWrite(BIN2, LOW);  // set pin 2 to low
    }
    else if (motorSpeed < 0) // if the motor should drive backward (negative speed)
    {
        digitalWrite(BIN1, LOW);  // set pin 1 to low
        digitalWrite(BIN2, HIGH); // set pin 2 to high
    }
    else // if the motor should stop
    {
        digitalWrite(BIN1, LOW); // set pin 1 to low
        digitalWrite(BIN2, LOW); // set pin 2 to low
    }
    analogWrite(PWMB, abs(motorSpeed)); // now that the motor direction is set, drive it at the entered speed
}
 
/********************************************************************************/
void rightMotor(int motorSpeed) // function for driving the right motor
{
    if (motorSpeed > 0) // if the motor should drive forward (positive speed)
    {
        digitalWrite(AIN1, HIGH); // set pin 1 to high
        digitalWrite(AIN2, LOW);  // set pin 2 to low
    }
    else if (motorSpeed < 0) // if the motor should drive backward (negative speed)
    {
        digitalWrite(AIN1, LOW);  // set pin 1 to low
        digitalWrite(AIN2, HIGH); // set pin 2 to high
    }
    else // if the motor should stop
    {
        digitalWrite(AIN1, LOW); // set pin 1 to low
        digitalWrite(AIN2, LOW); // set pin 2 to low
    }
    analogWrite(PWMA, abs(motorSpeed)); // now that the motor direction is set, drive it at the entered speed
}

L293D_IRremote_estop_ultrasonic.ino

• See simulation | repo

L293D_IRremote_estop_ultrasonic.ino

#include <Arduino.h>
 
// PIN VARIABLES
int buttonPin = 7;
int buttonState = 0;
int LED_PIN = 13;
 
/***IRremote variables*************************************************************************/
#include <IRremote.h>
 
#define IR_RECEIVE_PIN 11
 
// IRremote Codes
#define IR_BUTTON_1 12
#define IR_BUTTON_2 24
#define IR_BUTTON_3 94
#define IR_BUTTON_PLAY_PAUSE 64
#define IR_BUTTON_POWER 69        // Power button
#define IR_BUTTON_REWIND 68       // Rewind button
#define IR_BUTTON_FAST_FORWARD 67 // Fast-forward button
#define IR_BUTTON_VOLUME_UP 70    // Volume Up
#define IR_BUTTON_VOLUME_DOWN 21  // Volume Down
 
/***Motor Driver variables*************************************************************************/
// TB6612FNG Motor Driver
// the right motor will be controlled by the motor A pins on the motor driver
const int PWMA = 5; // speed control pin on the motor driver for the right motor
const int AIN1 = 2; // control pin 1 on the motor driver for the right motor
const int AIN2 = 3; // control pin 2 on the motor driver for the right motor
 
// the left motor will be controlled by the motor B pins on the motor driver
const int PWMB = 6; // speed control pin on the motor driver for the left motor
const int BIN1 = 8; // control pin 1 on the motor driver for the left motor
const int BIN2 = 9; // control pin 2 on the motor driver for the left motor
 
// L293D mapping
const int IN1_M1 = AIN1; // Control pin 1 for the right motor (Motor A)
const int IN2_M1 = AIN2; // Control pin 2 for the right motor (Motor A)
const int PWM_M1 = PWMA; // Speed control for the right motor (Motor A)
 
const int IN1_M2 = BIN1; // Control pin 1 for the left motor (Motor B)
const int IN2_M2 = BIN2; // Control pin 2 for the left motor (Motor B)
const int PWM_M2 = PWMB; // Speed control for the left motor (Motor B)
int speed = 150;
 
// VARIABLES
int motorSpeed = 0; // starting speed for the motor
 
/***Servo and Ultrasonic*************************************************************************/
#include <Servo.h>
#define SERVO_PIN 4            // Pin to which the servo motor is attached
#define ULTRASONIC_TRIG_PIN 12 // Pin for triggering the ultrasonic pulse
#define ULTRASONIC_ECHO_PIN 10 // Pin for receiving the ultrasonic echo
// Define variables for time measurement and calculated distance
#define SOUND_SPEED 0.034 // Speed of sound in cm per microsecond (340 m/s)
long timeInterval;        // Variable to store pulse duration
int measuredDistance;     // Variable to store calculated distance
Servo motorControl;       // Servo object to control motor movement
 
unsigned long previousMillis = 0; // Stores the last time a servo step was taken
// const int sweepInterval = 80;         // Interval between servo movements (in milliseconds)
const int sweepInterval = 30;
int sweepDirection = 1; // 1 for increasing angle, -1 for decreasing
// int servoAngle = 15;    // Start angle of the servo
int servoAngle = 100; // Start angle of the servo
 
// Function declarations
void forward();
void backward();
void turnLeft();
void turnRight();
void stop();
void speedUp();
void speedDown();
void rightMotor(int speed);
void leftMotor(int speed);
int getDistance();
void getSonar();
 
void setup()
{
    // set the motor control pins as outputs
    pinMode(AIN1, OUTPUT);
    pinMode(AIN2, OUTPUT);
    pinMode(PWMA, OUTPUT);
 
    pinMode(BIN1, OUTPUT);
    pinMode(BIN2, OUTPUT);
    pinMode(PWMB, OUTPUT);
 
    Serial.begin(115200);                      // begin serial communication with the computer
    Serial.println("To infinity and beyond!"); // test the serial connection
    Serial.print("Motor Speed: ");             // print the speed that the motor is set to run at
    Serial.println(speed);
 
    IrReceiver.begin(IR_RECEIVE_PIN, ENABLE_LED_FEEDBACK);
 
    pinMode(buttonPin, INPUT_PULLUP); // set this as a pullup to sense whether the switch is flipped
 
    // Servo and Ultrasonic Sensor
    pinMode(ULTRASONIC_TRIG_PIN, OUTPUT); // Configure the trigger pin as an output
    pinMode(ULTRASONIC_ECHO_PIN, INPUT);  // Configure the echo pin as an input
    motorControl.attach(SERVO_PIN);       // Attach the servo object to its designated pin
    motorControl.write(servoAngle);
    measuredDistance = getDistance(); // Get distance again
                                      //    Serial.print(angle);        // Print angle while moving back
    Serial.print(",");                // Print separator
    Serial.print(measuredDistance);   // Print measured distance
    Serial.print(".");                // Print separator
}
 
void loop()
{
    if (IrReceiver.decode())
    {
        int command = IrReceiver.decodedIRData.command;
        Serial.println(command);
 
        // Handle the received IR command
        switch (command)
        {
        case IR_BUTTON_1:
            Serial.println("Pressed on button 1");
            speedDown();
            break;
        case IR_BUTTON_2:
            Serial.println("Pressed on button 2");
            speedUp();
            break;
        case IR_BUTTON_3:
            Serial.println("Pressed on button 3");
            break;
        case IR_BUTTON_PLAY_PAUSE:
            Serial.println("Pressed on button Play/Pause");
            stop();
            break;
        case IR_BUTTON_POWER:
            Serial.println("Pressed on button Power");
            break;
        case IR_BUTTON_REWIND:
            Serial.println("Pressed on button Rewind");
            turnLeft();
            break;
        case IR_BUTTON_FAST_FORWARD:
            Serial.println("Pressed on button Fast Forward");
            turnRight();
            break;
        case IR_BUTTON_VOLUME_UP:
            Serial.println("Pressed on button Volume Up");
            forward();
            break;
        case IR_BUTTON_VOLUME_DOWN:
            Serial.println("Pressed on button Volume Down");
            backward();
            break;
        default:
            Serial.print("Unknown button code received: ");
            Serial.println(command);
            break;
        }
 
        IrReceiver.resume(); // Prepare for the next IR signal
    }
 
    // "E-stop" button
    const int debounceDelay = 50; // 50ms debounce
    static unsigned long lastDebounceTime = 0;
    static int lastButtonState = HIGH;
    int currentState = digitalRead(buttonPin);
    if (currentState != lastButtonState)
    {
        lastDebounceTime = millis();
    }
    if ((millis() - lastDebounceTime) > debounceDelay)
    {
        if (currentState == LOW)
        {
            stop();
            digitalWrite(LED_PIN, HIGH);
        }
    }
    lastButtonState = currentState;
 
    // Servo and Ultrasonic
    if (measuredDistance < 1)
    { // Stop if an obstacle is detected
        stop();
        Serial.println("Obstacle detected! Stopping...");
    }
    // Sweep servo non-blocking
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= sweepInterval)
    {
        previousMillis = currentMillis;
        motorControl.write(servoAngle); // Move servo to the current angle
        getSonar();
        // Update the servo angle for the next step
        servoAngle += sweepDirection * 1; // Increment angle by 5 degrees
        if (servoAngle <= 15 || servoAngle >= 165)
        {
            sweepDirection *= -1; // Reverse direction at boundaries
        }
    }
}
 
// Motor control functions
void forward()
{
    Serial.println("forward");
    // analogWrite(PWM_M1, speed);
    // analogWrite(PWM_M2, speed);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
    leftMotor(speed);
    rightMotor(speed);
}
 
void backward()
{
    Serial.println("backward");
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
    digitalWrite(IN1_M1, LOW);
    digitalWrite(IN2_M1, HIGH);
    digitalWrite(IN1_M2, LOW);
    digitalWrite(IN2_M2, HIGH);
 
    // back up
    // rightMotor(-255);
    // leftMotor(-255);
}
 
void turnLeft()
{
    Serial.println("turnLeft");
    // analogWrite(PWM_M1, 0);
    // analogWrite(PWM_M2, speed);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
 
    // Temp workaround
    leftMotor(-speed);
    rightMotor(speed);
}
 
void turnRight()
{
    Serial.println("turnRight");
    // analogWrite(PWM_M1, speed);
    // analogWrite(PWM_M2, 0);
    // digitalWrite(IN1_M1, HIGH);
    // digitalWrite(IN2_M1, LOW);
    // digitalWrite(IN1_M2, HIGH);
    // digitalWrite(IN2_M2, LOW);
 
    // Temp workaround
    leftMotor(speed);
    rightMotor(-speed);
}
 
void stop()
{
    Serial.println("stop");
    //    digitalWrite(IN1_M1, LOW);
    //    digitalWrite(IN2_M1, LOW);
    //    digitalWrite(IN1_M2, LOW);
    //    digitalWrite(IN2_M2, LOW);
 
    rightMotor(0);
    leftMotor(0);
}
 
void speedUp()
{
    Serial.println("speedUp");
    speed += 10;
    if (speed > 255)
        speed = 255;
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
}
 
void speedDown()
{
    Serial.println("speedDown");
    speed -= 10;
    if (speed < 0)
        speed = 0;
    analogWrite(PWM_M1, speed);
    analogWrite(PWM_M2, speed);
}
 
/********************************************************************************/
void leftMotor(int motorSpeed) // function for driving the left motor
{
    if (motorSpeed > 0) // if the motor should drive forward (positive speed)
    {
        digitalWrite(BIN1, HIGH); // set pin 1 to high
        digitalWrite(BIN2, LOW);  // set pin 2 to low
    }
    else if (motorSpeed < 0) // if the motor should drive backward (negative speed)
    {
        digitalWrite(BIN1, LOW);  // set pin 1 to low
        digitalWrite(BIN2, HIGH); // set pin 2 to high
    }
    else // if the motor should stop
    {
        digitalWrite(BIN1, LOW); // set pin 1 to low
        digitalWrite(BIN2, LOW); // set pin 2 to low
    }
    analogWrite(PWMB, abs(motorSpeed)); // now that the motor direction is set, drive it at the entered speed
}
 
/********************************************************************************/
void rightMotor(int motorSpeed) // function for driving the right motor
{
    if (motorSpeed > 0) // if the motor should drive forward (positive speed)
    {
        digitalWrite(AIN1, HIGH); // set pin 1 to high
        digitalWrite(AIN2, LOW);  // set pin 2 to low
    }
    else if (motorSpeed < 0) // if the motor should drive backward (negative speed)
    {
        digitalWrite(AIN1, LOW);  // set pin 1 to low
        digitalWrite(AIN2, HIGH); // set pin 2 to high
    }
    else // if the motor should stop
    {
        digitalWrite(AIN1, LOW); // set pin 1 to low
        digitalWrite(AIN2, LOW); // set pin 2 to low
    }
    analogWrite(PWMA, abs(motorSpeed)); // now that the motor direction is set, drive it at the entered speed
}
 
/********************************************************************************/
// Function to calculate the distance from ultrasonic sensor
int getDistance()
{
    // Start trigger pulse
    digitalWrite(ULTRASONIC_TRIG_PIN, LOW); // Set trigger pin to LOW to reset
    delayMicroseconds(2);                   // Short delay to ensure clean pulse
 
    digitalWrite(ULTRASONIC_TRIG_PIN, HIGH); // Start a pulse with trigger HIGH
    delayMicroseconds(10);                   // Pulse duration of 10 microseconds
    digitalWrite(ULTRASONIC_TRIG_PIN, LOW);  // End pulse by setting LOW
 
    timeInterval = pulseIn(ULTRASONIC_ECHO_PIN, HIGH); // Measure time of pulse
 
    // Calculate distance (in cm) based on time and speed of sound
    measuredDistance = timeInterval * SOUND_SPEED / 2;
    return measuredDistance; // Return calculated distance
}
 
void getSonar()
{
    measuredDistance = getDistance(); // Get distance again
    Serial.print(servoAngle);         // Print angle while moving back
    Serial.print(",");                // Print separator
    Serial.print(measuredDistance);   // Print measured distance
    Serial.print(".");                // Print separator
}