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// Connect left motor +ve terminal to M1+ and -ve to M1- ports and similarly connect M2.

// Declare constants.

#include <Servo.h>

//declare servo as object.

Servo steeringServo;

// accelerator is used to control Frobo speed. Remember PWM!

const int accelerator = 5;

//Moves left motor in forward direction.

const int leftMotorFwd = A0;

// Moves left motor is backward direction.

const int leftMotorRev = A1;

//Moves right motor in forward direction.

const int rightMotorFwd = A2;

// Moves right motor in backward direction.

const int rightMotorRev = A3;

//We need not define pinMode as all pins are taken as INPUT by default. Setup code runs only once when program starts.

void setup()

{

// Define LEDs and Motors as outputs. Inputs are defined by default.

pinMode(accelerator, OUTPUT);

pinMode(leftMotorFwd, OUTPUT);

pinMode(leftMotorRev, OUTPUT);

pinMode(rightMotorFwd, OUTPUT);

pinMode(rightMotorRev, OUTPUT);

// Let us open the serial ports with data rate 9600 bits /second

steeringServo.attach(6);

Serial.begin(9600);

//Declare starting position. Use this to set your wheel.

steeringServo.write(90);

}

//This loop code runs repeatedly

void loop()

{

//This is the basic froboduino code for controlling motors to move in different directions.

//This code will move Frobo forwards for 5 seconds.

// accelerator powers the motors, so any movement, we have to set it "High".

Serial.println("Frobo will move forward for 5 seconds");

digitalWrite (accelerator, HIGH);

digitalWrite(leftMotorFwd, HIGH);

digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);

digitalWrite (rightMotorRev, LOW);

// Let this motion continue for 5 seconds (5000 mili seconds).

delay(5000);

// This code will now turn frobo left for 3 seconds and will move it forward for 5 seconds.

// by stopping left motor and running right motor, we will move Frobo in left direction.

Serial.println("Now Frobo will turn left");

digitalWrite(leftMotorFwd, LOW);

digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);

digitalWrite (rightMotorRev, LOW);

delay(3000);

Serial.println("Then Frobo will move forward for 5 seconds");

digitalWrite(leftMotorFwd, HIGH);

digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);

digitalWrite (rightMotorRev, LOW);

delay(5000);

digitalWrite(leftMotorFwd, LOW);

digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, LOW);

digitalWrite (rightMotorRev, LOW);

delay(1000);

//This code will Frobo backwards for 5 seconds.

Serial.println("Now Frobo will move backward for 5 seconds");

//digitalWrite(accelerator, HIGH);

digitalWrite(leftMotorFwd, LOW);

digitalWrite (leftMotorRev, HIGH);

digitalWrite(rightMotorFwd, LOW);

digitalWrite (rightMotorRev, HIGH);

delay(5000);

//This code will turn frobo in right direction for 3 seconds in backward motion.

Serial.println("Now Frobo will turn right in backward motion");

digitalWrite(leftMotorFwd, LOW);

digitalWrite (leftMotorRev, HIGH);

digitalWrite(rightMotorFwd, LOW);

digitalWrite (rightMotorRev, LOW);

delay(3000);

// This code will stopFrobo for 5 seconds.

digitalWrite(leftMotorFwd, LOW);

digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, LOW);

digitalWrite (rightMotorRev, LOW);

delay(5000);

digitalWrite(leftMotorFwd, HIGH);

digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);

digitalWrite (rightMotorRev, LOW);

delay(5000);

//Imagine controlling motion to create dance effects. Try moving from forward for 1 second and then turn left for a second and turn right for a second and make it move backwards for 4 seconds. This is an exercise for you.

}

// Declare pins for your Leds. const int, #define are used to define fixed pins.

const int ledLeft = 9;

const int ledRight = 10;

//Declare led state variables below. These define the current state of Leds. Notice that we are setting one state "LOW" and the other state "HIGH"

int ledLeftState = LOW;

int ledRightState = HIGH;

/*Declare time interval variables below. Notice that we are using "unsigned long" here and we used "int" earlier for led states. Why?

Please know about these different variable types below.*/

unsigned long previousMillis = 0;

unsigned long interval = 100;

unsigned long currentMillis = 0;

// setup code runs once when the froboduino is swtched on.

void setup()

{

// Here, we declare that ledLeft and ledRight are Outputs. It is important. Inputs are taken by default.

pinMode(ledLeft, OUTPUT);

pinMode(ledRight, OUTPUT);

//This is meant for program testing in serial monitor.

Serial.begin(9600);

}

// This code runs again and again when froboduino is powered.

void loop()

{

//This  is to set the value of "currentMillis" equal to milli seconds since the program started.

currentMillis = millis();

/*previousMillis began with value 0, so we check the difference of currentMillis and previousMillis, and if this bigger than or equal to "interval"

(defined in variables in starting), we command to change the led states*/

if ((currentMillis - previousMillis) >= interval){

previousMillis = currentMillis;

if (ledLeftState == LOW && ledRightState == HIGH){

ledLeftState = HIGH;

ledRightState = LOW;

}

// if the above statement is not correct, that is if two Led states are different, we give an "otherwise" command with "else".

else {

ledLeftState = LOW;

ledRightState = HIGH;

}

// Here we command the left and right Leds to follow the states. If ledLeftState is HIGH, the left Led will turn on.

digitalWrite(ledLeft, ledLeftState);

digitalWrite(ledRight, ledRightState);

/*You can read about various variable types here. https://www.arduino.cc/en/Reference/VariableDeclaration

Variable "int" is 2 byte (1 byte is 8 bits, so it is 16 bit number) variable which can be both negative and positive number. The range of "int" variable value is -32,768 to 32,767, which is equal to -2^15 to 2^15-1.

Variable "unsigned long" is 4 byte (32 bit) number with maximum value of 2^32-1, which is 4,294,967,295. All unsigned variables are only positive numbers. This is a useful variable to store time in milli second and micro second.

IMPORTANT- After the variable value reaches the maximum, it rolls over to the minimum value.*/

}

}

// We need to include servo.h library. Servo.h library is included in all latest Arduino IDE versions as a standard Arduino Library.

#include <Servo.h>

//declare servo as object.

Servo steeringServo;

// accelerator is used to control Frobo speed. Remember PWM!

const int accelerator = 5;

//Moves left motor in forward direction.

const int leftMotorFwd = A0;

// Moves left motor is backward direction.

const int leftMotorRev = A1;

//Moves right motor in forward direction.

const int rightMotorFwd = A2;

// Moves right motor in backward direction.

const int rightMotorRev = A3;

//Servo motor servoPosition. Servo sweeps 0- 180 degrees. We set the servo right in the middle at start.

int servoPos;

//We need not define pinMode as all pins are taken as INPUT by default. Setup code runs only once when program starts.

void setup()

{

// Define LEDs and Motors as outputs. Inputs are defined by default.

pinMode(accelerator, OUTPUT);

pinMode(leftMotorFwd, OUTPUT);

pinMode(leftMotorRev, OUTPUT);

pinMode(rightMotorFwd, OUTPUT);

pinMode(rightMotorRev, OUTPUT);

// Let us open the serial ports with data rate 9600 bits /second

steeringServo.attach(6);

Serial.begin(9600);

//Declare starting position. Use this to set your wheel.

steeringServo.write(90);

//Use delay of 5 seconds first time so you can mark center position to mount your wheel.

delay(5000);

}

//This loop code runs repeatedly

void loop()

{

//This is the basic froboduino code for controlling servo to move in different directions.

//This code will move steering wheel 90 degrees left and then 180 degrees right, then it will come back to middle.

// Now we declare the starting servo Position on steering Servo at 90 and turn by 1 degree each to full left at 0 degree.

// Read up on how to use "for" statements. These statements are used to repeat statement between two curly braces.

Serial.println("turning right");

for (servoPos = 90; servoPos <= 180; servoPos += 1) { // goes from 0 degrees to 180 degrees

// in steps of 1 degree

steeringServo.write(servoPos); // tell servo to go to servoPosition in variable 'servoPos'

delay(15); // waits 15ms for the servo to reach the servo Position

}

delay(2000);

Serial.println("turning left");

for (servoPos = 180; servoPos >= 0; servoPos -= 1) { // goes from 180 degrees to 0 degrees

steeringServo.write(servoPos); // tell servo to go to servoPosition in variable 'servoPos'

delay(15); // waits 15ms for the servo to reach the servoPosition

}

delay(2000);

Serial.println("Back to the middle");

for (servoPos = 0; servoPos <= 90; servoPos += 1) { // goes from 180 degrees to 0 degrees

steeringServo.write(servoPos); // tell servo to go to servoPosition in variable 'servoPos'

delay(15); // waits 15ms for the servo to reach the servoPosition

}

delay(2000);

}

// define pins numbers for "Trig" and "Echo" Pins of HC-SR04.

//Our Froboduino Ultrasonic (U) ports are connected to Arduino pin D2 and D3.

const int trigPin = 2;

const int echoPin = 3;

// defines variables. 

long duration;

int distance;

void setup() {

// Sets the trigPin as an Output

pinMode(trigPin, OUTPUT);

 // Sets the echoPin as an Input

 pinMode(echoPin, INPUT);

// Starts the serial communication

 Serial.begin(9600); }

  void loop() {

// Clears the trigPin

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

 // Sets the trigPin on HIGH state for 5 micro seconds

digitalWrite(trigPin, HIGH);

delayMicroseconds(5);

digitalWrite(trigPin, LOW);

// Reads the echoPin, returns the sound wave travel time in microseconds

duration = pulseIn(echoPin, HIGH);

// Calculate the distance. Sound travel at 343 M/s. So distance =durationX343 Meters/second = durationX34300 cms/ 1000*1000 microseconds = duration*.0343

// Divide the total distance travelled by sound by 2 as it goes and comes back to get distance from object.

distance= duration*0.0343/2;

// Prints the distance on the Serial Monitor . Serial monitor is not left top side of your Arduino IDE.

// Make sure to select right board and prt from tool menu.

Serial.print("Distance: ");

Serial.println(distance); }

// define pins numbers for "Trig" and "Echo" Pins of HC-SR04.
//Our Froboduino Ultrasonic (U) ports are connected to arduino pin D2 and.
// Define left and right Leds pins to D9, D10
const int trigPin = 2;
const int echoPin = 3;
const int leftLed = 9;
const int rightLed = 10;

// defines variables. We are defining "duration" as "long" variable and "distance" as "int". Arduino compiler treats diffrent variable types differently.

// Read Here to understand different "Integer Constants"
long duration;
int distance;

void setup() {

// Set left Led as output.

pinMode(leftLed, OUTPUT);

// Set right Led as output.

pinMode(rightLed, OUTPUT);
// Sets the trigPin as an Output
pinMode(trigPin, OUTPUT);
// Sets the echoPin as an Input. It is not important to define inputs, but for clarity of this we are showing it heere.

pinMode(echoPin, INPUT);
// Starts the serial communication

Serial.begin(9600); }

void loop() {
// Clears the trigPin
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Sets the trigPin on HIGH state for 5 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(5);
digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculate the distance. Sound travel at 343 M/s. So distance =durationX343 Meters/second = durationX34300 cms/ 1000*1000 microseconds = duration*.0343
// Divide the total distance travelled by sound by 2 as it goes and comes back to get distance from object.
distance= duration*0.0343/2;
// Prints the distance on the Serial Monitor
Serial.print("Distance: ");
Serial.println(distance);
//Code for When distance measured is below 10 cms . Light up left Led. Turn off right led.

if (distance <= 10){
//Light up left Led
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, LOW);
}
//Code for When distance measured is above 10 cms but less than 1000 cms . Light up right Led. Turn off left Led.
if (distance >= 10 && distance <=1000){
//light up right Led
digitalWrite(rightLed, HIGH);
digitalWrite(leftLed, LOW);
}
//Code for When distance measured is above 1000 cms and less than 3000 cms . Light up left and right Led.
if (distance >= 1000 && distance <= 3000){
//light up left and right Led
digitalWrite(rightLed, HIGH);
digitalWrite(leftLed, HIGH);
}

}

/* On your froboduino board, connect one of the  LDRs to LD1 +ve and -ve ports. LDR is non-directional, so you can put any leg to +ve or -ve.

LD1 port is connected on control PCB A4 pin. A4 is is an analog pin abd can read voltage as values.  Let us first define the pin for LDR.*/

const int LDR = A4;

//We need not define pinMode as all pins are taken as INPUT by default. Setup code runs only once when program starts.

void setup()

{

// Let us open the serial ports with data rate 9600 bits /second

Serial.begin(9600);

}

//This loop code runs repeatedly

void loop()

{

//Record the analog value at pin A4

int ldrValue = analogRead(A4);

// Froboduino analog reference voltage is 5V.

// Analog pins read voltage between 0 to 5V. Arduino 328P has an 10 bit analog to digotal converter (ADC) on 6 pins from A0 to A5. 

// The ADC converts voltage from 0 to 1023, i.e. 2^10-1 (Being a 10 bit ADC), so that each value corresponds to 5000mV/1024 = 4.88mV

// Let us convert ldrValue to voltage. We will use "float" variable for the decimal value.

float ldrVoltage = ldrValue*4.88 ;

// We use Characters within "Characters" in Serial.print to show characters in serial monitor as "Characters"

Serial.print("LDR analog reading is ");

Serial.print(analogRead(A4));

Serial.print("LDR volatge is ");

Serial.print(ldrVoltage);

Serial.println("milli volts");

}

#include <Servo.h>

//declare servo as object.

Servo steeringServo;

const int LD1 = A4;

const int LD2 = A5;

const int leftLed = 9;

const int rightLed = 10;

// accelerator is used to control Frobo speed. Remember PWM!

const int accelerator = 5;

const int leftMotorFwd = A0;

const int leftMotorRev = A1;

const int rightMotorFwd = A2;

const int rightMotorRev = A3;;

int servoPos;

// Setup code runs only once when program starts.

void setup()

{

//declare Leds as outputs.

pinMode(leftLed, OUTPUT);

pinMode(rightLed, OUTPUT);

pinMode(accelerator, OUTPUT);

pinMode(leftMotorFwd, OUTPUT);

pinMode(leftMotorRev, OUTPUT);

pinMode(rightMotorFwd, OUTPUT);

pinMode(rightMotorRev, OUTPUT);

steeringServo.attach(6);

steeringServo.write(90);;

//We need not define LD1 and LD2 as inputs pinMode as all pins are taken as INPUT by default

// Let us open the serial ports with data rate 9600 bits /second

Serial.begin(9600);

}

//This loop code runs repeatedly

void loop()

{

digitalWrite (accelerator, HIGH);

//Record the analog value at pin A3

int ldrValue1 = analogRead(A4);

int ldrValue2 = analogRead(A5);

Serial.println(ldrValue1);

Serial.println(ldrValue2);

delay(500);

// Let us try to do something useful with light reading of both LDR sensors.

//Let us compare both readings of LDRs and then light up left or right Leds if left and right LDR shows

// LDR value goes down when it sees more light.

// this code will light up left Led if value of left LDR is lower.

//Frobo will turn where it sees more light, until both LDRs  start getting close enough values.

if (ldrValue2- ldrValue1 > 25){

digitalWrite(leftLed, HIGH);

digitalWrite(rightLed, LOW);

digitalWrite (accelerator, HIGH);

//Frobo sees more light on left side, so we will turn servo wheel leftwards.

Serial.println("turning left");

    steeringServo.write(75);

    digitalWrite(leftMotorFwd, LOW);

    digitalWrite (leftMotorRev, LOW);

     digitalWrite(rightMotorFwd, HIGH);

    digitalWrite (rightMotorRev, LOW);

}

// this code will light up right Led and turn right if value of right LDR is higher.

 if (ldrValue1- ldrValue2 > 25){

digitalWrite(leftLed, LOW);

digitalWrite(rightLed, HIGH);

 //Frobo sees more light on right side, so we will turn it leftwards.

/*for (servoPos = 90; servoPos <= 135; servoPos += 1) {// goes from 0 degrees to 180 degrees

    // in steps of 1 degree

    steeringServo.write(servoPos);              // tell servo to go to servoPosition in variable 'servoPos'

    delay(15);                       // waits 15ms for the servo to reach the servoPosition

  }*/

    Serial.println("turning right");

    steeringServo.write(105);

    digitalWrite(leftMotorFwd, HIGH);

    digitalWrite (leftMotorRev, LOW);

     digitalWrite(rightMotorFwd, LOW);

    digitalWrite (rightMotorRev, LOW);

}

// this code will light up blink left and right Led if value of both LDR is almost equal.

int X = ldrValue1 - ldrValue2;

int Y = abs(X);

if (Y < 25 ){

  //Frobo sees almost equal light on both side, so we will it forwards.

  Serial.println("Moving Straight");

 steeringServo.write(90);

     digitalWrite(leftMotorFwd, HIGH);

    digitalWrite (leftMotorRev, LOW);

     digitalWrite(rightMotorFwd, HIGH);

    digitalWrite (rightMotorRev, LOW);

digitalWrite(leftLed, HIGH);

digitalWrite(rightLed, LOW);

delay(300);

digitalWrite(leftLed, LOW);

digitalWrite(rightLed, HIGH);

delay(300);

}

}

// On your Froboduino board, connect one of the left IR LED to I1 +ve and -ve ports, IR Diode to D1+ and D1- in reverse bias. Similarly connect right IR LED and diode to I2 and D2.

// Connect left motor +ve terminal to M1+ and -ve to M1- ports and similarly connect M2.

//Connect Leds to L1+ and L1-, L2+ and L2-.

// Declare constants.

const int IRD1 = A6;

const int IRD2 = A7;

const int leftLed = 9;

const int rightLed = 10;

// accelerator is used to control Frobo speed. Remember PWM!

const int accelerator = 5;

const int leftMotorFwd = A0;

const int leftMotorRev = A1;

const int rightMotorFwd = A2;

const int rightMotorRev = A3;

//Define vaiables left and right states as boolean ( 0 or 1 state) reading of IR diodes.

int leftState = 0;

int rightState =0;

//Define states for different stages of searching.

//First step is to search left for 5 seconds. So, we define if left search has been done.

int searchLeft = 0;

//After left search, we move right for the line and keep searching until line is found. so we define right search here.

int searchRight = 0;

//Here we define line found.

int lineFound = 0;

// Here we define time variable to track search time. Time variables are usually defined as unsigned long.

unsigned long searchStartTime = 0;

unsigned long searchNowTime = 0;

unsigned long searchTime = 0;

// Define Led state to light up Leds.

int ledState = 0;

//Define led time as unsigned long.

unsigned long ledStartTime = 0;

unsigned long ledNowTime = 0;

unsigned long ledTime = 0;

//We need not define pinMode as all pins are taken as INPUT by default. Setup code runs only once when program starts.

void setup()

{

// Define LEDs and Motors as outputs. Inputs are defined by default.

pinMode(leftLed, OUTPUT);

pinMode(rightLed, OUTPUT);

pinMode(accelerator, OUTPUT);

pinMode(leftMotorFwd, OUTPUT);

pinMode(leftMotorRev, OUTPUT);

pinMode(rightMotorFwd, OUTPUT);

pinMode(rightMotorRev, OUTPUT);

// Let us open the serial ports with data rate 9600 bits /second

Serial.begin(9600);

}

//This loop code runs repeatedly

void loop()

{

leftState = analogRead(IRD1);

rightState = analogRead(IRD2);

//Draw a black thick line on white surface and leave robot over the line.

//Bring frobo left side over the black line.

Serial.print("left ");

Serial.println(leftState);

Serial.print("right ");

Serial.println(rightState);

if (leftState <= 699){

digitalWrite(leftLed, HIGH);

Serial.println("Left side sees black line");

}

// Move frobo away from line and put it white surface.

if (leftState >= 700){

digitalWrite(leftLed, LOW);

Serial.println("No black line on left side");

}

//The code above doesn't work as expected.

//Turn the small blue pot on LM293 pin3 Froboduino board, till Frobo starts working as adjusted.

// Now, let us repeat the same thing for right side.

if (rightState <= 699){

digitalWrite(leftLed, HIGH);

Serial.println("Right side sees black line");

}

// Move frobo away from line and put it white surface.

if (rightState >= 700){

digitalWrite(leftLed, LOW);

Serial.println("No black line on right side");

}

delay(1000);

}

// On your froboduino board, connect one of the left IR LED to to I1 +ve and -ve ports, IR Diode to D1+ and D1- in reverse bias. Similarly connect right IR LED and diode to I2 and D2.
// Connect left motor +ve terminal to M1+ and -ve to M1- ports and similarly connect M2.
//Connect Leds to L1+ and L1-, L2+ and L2-.
// Place your Frobo over a thich black line facing any direction, Frobo will find the line and follow it.
// Declare constants.
#include <Servo.h>
//delare servo as object.
Servo steeringServo;
const int IRD1 = A6;
const int IRD2 = A7;
const int leftLed = 9;
const int rightLed = 10;
// accelerator is used to control Frobo speed. Remember PWM!
const int accelerator = 5;
const int leftMotorFwd = A0;
const int leftMotorRev = A1;
const int rightMotorFwd = A2;
const int rightMotorRev = A3;
const int buzzer = 1;
//Define vaiables left and right states as boolean ( 0 or 1 state) reading of IR diodes.
int leftRead = 0;
int rightRead =0;
// Define variable left and right State to mark last time FRobo swa line on left or right .
int leftState = 0;
int rightState = 0;

int servoPos;

//Here we define line found.
int lineFound = 0;
// Here we define time variable to track search time. Time variables are usually defined as unsigned long.
unsigned long searchStartTime = 0;
unsigned long searchNowTime = 0;
unsigned long searchTime = 0;
// Define Led state to light up Leds.
int ledState = 0;
//Define led time as unsigned long.
unsigned long ledStartTime = 0;
unsigned long ledNowTime = 0;
unsigned long ledTime = 0;
//We need not define pinMode as all pins are taken as INPUT by default. Setup code runs only once when program starts.

void setup()

{
// Define LEDs and Motors as outputs. Inputs are defined by default.
pinMode(leftLed, OUTPUT);
pinMode(rightLed, OUTPUT);
pinMode(accelerator, OUTPUT);
pinMode(leftMotorFwd, OUTPUT);
pinMode(leftMotorRev, OUTPUT);
pinMode(rightMotorFwd, OUTPUT);
pinMode(rightMotorRev, OUTPUT);
pinMode(buzzer, OUTPUT);

// Let us open the serial ports with data rate 9600 bits /second

Serial.begin(9600);
steeringServo.attach(6);

steeringServo.write(90);
}

//This loop code runs repeatedly

void loop()

{
// We use analogRead here as Pins A6 and A7 can only perform analogRead but not digitalRead as with other pins.
leftRead = analogRead(IRD1);
rightRead = analogRead(IRD2);
//Serial.println(leftRead);
//Serial.println(rightRead);
//Draw a black thick line with dull black electricity tape on white surface and leave robot over the line.
if (lineFound == 0){
if(leftRead <= 100 || rightRead <= 100){
Serial.println("line seen");
Serial.println("leftRead");
Serial.println(leftRead);
Serial.println("rightRead");
Serial.println(rightRead);
lineFound = 1;
}

}
//Serial.println("Following line");
if (lineFound == 1){
// When left photodiode sees black line, we turn Frobo left by runnong only right motor.
if (leftRead <=100 && rightRead >100){
// We call leftLed function to show Frobo seeing line in the left side.
Serial.println("seeing line on left");

leftLedBlink();
steeringServo.write(85);
digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, LOW);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);
digitalWrite (rightMotorRev, LOW);
Serial.println("leftRead");
Serial.println(leftRead);
Serial.println("rightRead");
Serial.println(rightRead);
//delay(1000)*/
leftState = 1;
rightState = 0;
Serial.println("left State");
Serial.println(leftState);
}
// When right photodiode sees black line, we turn Frobo right by running only left motor.

else if (leftRead > 100 && rightRead <= 100){
// We call rightLed function to show Frobo seeing line in the right side.
Serial.println("seeing line on right");

rightLedBlink();
steeringServo.write(95);

digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, HIGH);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, LOW);
digitalWrite (rightMotorRev, LOW);
Serial.println("leftRead");
Serial.println(leftRead);
Serial.println("rightRead");
Serial.println(rightRead);
//delay(1000);
leftState = 0;
rightState = 1;
Serial.println("right State");
Serial.println(rightState);
}
//When both left and right photodiodes see black line, Frobo moves forward.
else if (leftRead <= 100 && rightRead <= 100 ){
// WE call bothLed function to show both bright eyes with slow blinks.
Serial.println("seeing line on both");

bothLed();
steeringServo.write(90);
digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, HIGH);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);
digitalWrite (rightMotorRev, LOW);



Serial.println("leftRead");
Serial.println(leftRead);
Serial.println("rightRead");
Serial.println(rightRead);
//delay(1000);

}
else if (leftRead > 100 && rightRead > 100 ){
//When none of the photodiodes see black line, we set lineFound to 0 and lookLeft() and lookRight() programs will run to find the line.
//lineFound =0;
Serial.println("Can't see line");
Serial.println("leftRead");
Serial.println(leftRead);
Serial.println("rightRead");
Serial.println(rightRead);
// We now call ledBlink function to light left and right Leds aleternately to show confusion.
ledBlink();
if(leftState ==1 ){
steeringServo.write(75);
digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, LOW);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);
digitalWrite (rightMotorRev, LOW);
}
if (rightState == 1){
steeringServo.write(105);
digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, HIGH);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, LOW);
digitalWrite (rightMotorRev, LOW);
}
if (leftState == 0 && rightState == 0){
steeringServo.write(105);
digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, HIGH);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, LOW);
digitalWrite (rightMotorRev, LOW);
}
}
//delay(1000);

}
}

void ledBlink(){
// This code uses timer function millis() to set time intervals for leds to switch on and off after 200 milli seconds.
// Notice how we manipulate ledState by assigning it different values to decide which led will go on and off after defined intervals.
ledTime = ledNowTime - ledStartTime;
if (ledState == 0){
ledStartTime = millis();
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, LOW);
ledState =1;

}
if (ledState == 1){
ledNowTime = millis();
if(ledTime >= 200){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, HIGH);
ledNowTime = 0;
ledStartTime = millis();
ledState =2;
}
}
if (ledState == 2){
ledNowTime = millis();
if (ledTime >=200){
digitalWrite(rightLed, LOW);
ledNowTime = 0;
ledStartTime = ledNowTime;
ledState = 0;
}
}
}

void leftLedBlink(){
// This code uses timer function millis() to set time intervals for leds to switch on and off after 200 milli seconds.
// Notice how we manipulate ledState by assigning it different values to decide which led will go on and off after defined intervals.
ledTime = ledNowTime - ledStartTime;
if (ledState == 0){
ledStartTime = millis();
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, LOW);
ledState =1;

}
if (ledState == 1){
ledNowTime = millis();
if(ledTime >= 500){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
ledNowTime = 0;
ledStartTime = millis();
ledState =0;
}
}

}
void rightLedBlink(){
// This code uses timer function millis() to set time intervals for leds to switch on and off after 200 milli seconds.
// Notice how we manipulate ledState by assigning it different values to decide which led will go on and off after defined intervals.
ledTime = ledNowTime - ledStartTime;
if (ledState == 0){
ledStartTime = millis();
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, HIGH);
ledState =1;

}
if (ledState == 1){
ledNowTime = millis();
if(ledTime >= 500){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
ledNowTime = 0;
ledStartTime = millis();
ledState =0;
}
}

}
void bothLed(){
// This code uses timer function millis() to set time intervals for leds to switch on and off after 200 milli seconds.
// Notice how we manipulate ledState by assigning it different values to decide which led will go on and off after defined intervals.
ledTime = ledNowTime - ledStartTime;
if (ledState == 0){
ledStartTime = millis();
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, HIGH);
ledState =1;

}
if (ledState == 1){
ledNowTime = millis();
if(ledTime >= 1000){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
ledNowTime = 0;
ledStartTime = millis();
ledState =0;
}
}

}
//Improve thos code for different situations. Like when Frobo is not placed over the line drawn. Think and let us know.

#include <Servo.h>
//declare inputs and output devices.
const int trigPin = 2;
const int echoPin = 3;
const int LD1 = A4;
const int LD2 = A5;
const int IRD1 = A6;
const int IRD2 = A7;
const int leftLed = 9;
const int rightLed = 10;
const int accelerator = 5;
const int leftMotorFwd = A0;
const int leftMotorRev = A1;
const int rightMotorFwd = A2;
const int rightMotorRev = A3;
const int buzzer = 0;
Servo steeringServo;
//Declare variables we are going to monitor.
int servoPos = 90;
int ldrValue1 = 0;
int ldrValue2 = 0;
int lightMode = 1;
//Define vaiables left and right states as boolean ( 0 or 1 state) reading of IR diodes.
bool leftState = 0;
bool rightState =0;
// Declare left and right Led States for controlling Leds.
int leftLedState = 0;
int rightLedState = 0;
int ledInterval = 500;
//We declare another set of variables to decide if Frobo moved over the boundary line.
int lineDetect =0;
// This one if Frobo dtected line on left side.
int lineDetectLeft = 0;
//This one if Frobo dtected line on right side.
int lineDetectRight = 0;
//Her ewe declare detect time variables as unsigned long types.
unsigned long detectStartTime = 0;
//We will define these variables in the code.
unsigned long detectNowTime = 0;
unsigned long detectOnTime = 0;
//Declare Led start time.
unsigned long ledStartTime = 0;
unsigned long ledNowTime = 0;
unsigned long ledOnTime = 0;

//We need not define pinMode as all pins are taken as INPUT by default. Setup code runs only once when program starts.

void setup()

{
// Define buzeer, LEDs, Motors and Servo as outputs. Inputs are defined by default.
pinMode(trigPin, OUTPUT);
pinMode(leftLed, OUTPUT);
pinMode(rightLed, OUTPUT);
pinMode(accelerator, OUTPUT);
pinMode(leftMotorFwd, OUTPUT);
pinMode(leftMotorRev, OUTPUT);
pinMode(rightMotorFwd, OUTPUT);
pinMode(rightMotorRev, OUTPUT);
pinMode(buzzer, OUTPUT);
// Let us open the serial ports with data rate 9600 bits /second
steeringServo.attach(6);
Serial.begin(9600);

}

//This loop code runs repeatedly

void loop()

{
// This code runs repeatedly.
//Read both LDR values.
int ldrValue1 = analogRead(A4);
int ldrValue2 = analogRead(A5);
/* Note down LDR values in different directions when light is on and repeat the same by turning off the light.
LDR values go up when light is low and lower when there is more light. we will use the highest value when light is on as a threshold value to make Frobo to sense when light is on and when it is off.
*/

Serial.print("Left LDR value ");
Serial.println(ldrValue1);
Serial.print("Right LDR value ");
Serial.println(ldrValue2);
//Remove "//" from next line when taking LDR values.so you can record LDR values in Serial monitor for easy reading.
//delay(1000);
/*When light is off. We will see if ldrValues are higher than the minimum we recorded.
* Frobo will move only when lightMode =1.
* We are taking 300 here. Replace it with your recorded minimum. We will change int lightMode to 0.
*/
if (ldrValue1 <= 300 && ldrValue2 <= 300){
lightMode = 0;
}
//Program will run the below modules repeatedly.
// We write these programs in different modules separately for easier programming and debugging.
myBoundary();
ledPattern1();
ledPattern2();
ledPattern3();
ledPattern4();

}

// The code below is to program Frobo to remain within the boundary drawn.
void myBoundary(){
//Read IR diode state to check if Frobo sees the boundary.
leftState = digitalRead(IRD1);
rightState = digitalRead(IRD2);
// If there is enough light.
if (lightMode == 1){
// Frobo keeps moving forward. Both motors move forward.
digitalWrite(accelerator, HIGH);
digitalWrite(leftMotorFwd, HIGH);
digitalWrite (leftMotorRev, LOW);

digitalWrite(rightMotorFwd, HIGH);
digitalWrite (rightMotorRev, LOW);

// If both IR diodes sees line, move Frobo backwards and then turn left (or even right as you like but change code for right turn).
if (IRD1 == 0 || IRD2 == 0){
if(lineDetect == 0){
//Take time reading when line was detected.
detectStartTime = millis();

// Turn left motor backwards.
digitalWrite(leftMotorFwd, LOW);
digitalWrite (leftMotorRev, HIGH);
// Turn right motor backwards.
digitalWrite(rightMotorFwd, LOW);
digitalWrite (rightMotorRev, HIGH);

//Line found. So, we change the lineDetect to 1.

lineDetect = 1;
// We close the statement here as lineDetect state has changed.
}
}
if (lineDetect == 1){
// Take current time since detection.
detectNowTime = millis();
// Declare detectOnTime as time difference since line was detected.
detectOnTime = detectNowTime - detectStartTime;
// Now we want to Frobo to move backwards for 5 seconds (or you can decide) and then move forward while turning left.
if (detectOnTime >= 5000){
// Turn left motor forward.
servoPos = servoPos + 15;
steeringServo.write(servoPos);
digitalWrite(leftMotorFwd, HIGH);
digitalWrite (leftMotorRev, LOW);
// Turn right motor forward.
digitalWrite(rightMotorFwd, HIGH);
digitalWrite (rightMotorRev, LOW);
}
// Turn servo back by 15 degrees after 3 seconds more.
if (detectOnTime >=8000){
servoPos = servoPos - 15;
steeringServo.write(servoPos);

detectNowTime = 0;
detectStartTime = detectNowTime;
lineDetect =0;

}
}

// If right IR diode sees line, but left doesn't. Turn Servo left by 15 degrees for 5 seconds.
if (IRD1 == 1 || IRD2 == 0){
servoPos = servoPos - 15;
steeringServo.write(servoPos);
detectStartTime = millis();
lineDetectLeft = 1;
}
if (lineDetectLeft == 1){
detectNowTime = millis();
detectOnTime = detectNowTime - detectStartTime;
if (detectOnTime >= 5000);
//Turn servo back by 15 degrees after 5 seconds.
servoPos = servoPos +15;
steeringServo.write(servoPos);
detectNowTime = 0;
detectStartTime = detectNowTime;
lineDetectLeft = 0;

}

// If left IR diode sees line, but right doesn't. Turn Servo right by 15 degrees for 5 seconds.
if (IRD1 == 0 || IRD2 == 1){
servoPos = servoPos + 15;
steeringServo.write(servoPos);
detectStartTime = millis();
lineDetectRight = 1;
}
if (lineDetectRight == 1){
detectNowTime = millis();
detectOnTime = detectNowTime - detectStartTime;
if (detectOnTime >= 5000);
//Turn servo back by 15 degrees after 5 seconds.
servoPos = servoPos -15;
steeringServo.write(servoPos);
detectNowTime = 0;
detectStartTime = detectNowTime;
lineDetectRight = 0;

}
}
}
// This code will control Leds in a way so that Leds are On for 1.5 seconds and off for 100 mili seconds. Showing fear.
void ledPattern1(){
//This code will run only when light is normal and both IR diodes step on boundary.
if (lightMode == 1 && lineDetect == 1){
//define ledOnTime.

ledOnTime = ledNowTime - ledStartTime;

if (leftLedState == 0 && rightLedState == 0){
ledStartTime = millis();
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, HIGH);
//We use tone(pin, frequency) function to sound buzzer. Our buzzer is at pin 0 and frequency we have chsen here is 440 Hz.
tone(0, 440);
leftLedState = 1;
rightLedState = 1;
}
// This code lights up Leds for 1500 mili seconds (1.5 seconds)
if (leftLedState == 1 && rightLedState ==1){
ledNowTime = millis();
if (ledOnTime >= 1500){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
//Here we use noTone(pin) to silence the buzzer.
noTone(0);
leftLedState = 2;
rightLedState = 2;
}
}
if (leftLedState == 2 && rightLedState == 2){
if (ledOnTime >= 1600){
ledNowTime = ledStartTime;
leftLedState = 0;
rightLedState = 0;
}
}
}
}
//This code will control Leds when light is normal and when Frobo sees line on the left.
void ledPattern2(){
if (lightMode == 1 && lineDetectLeft == 1){
//We will light up right Led in this mode and blibk left.
digitalWrite(rightLed, HIGH);
//define ledOnTime.

ledOnTime = ledNowTime - ledStartTime;

if (leftLedState == 0){
ledStartTime = millis();
digitalWrite(leftLed, HIGH);
tone(0, 330);
leftLedState = 1;
}
// This code lights up left Led for 1500 mili seconds (1.5 seconds)
if (leftLedState == 1 ){
ledNowTime = millis();
if (ledOnTime >= 1500){
digitalWrite(leftLed, LOW);
noTone(0);
leftLedState = 2;
}
}
if (leftLedState == 2 ){
if (ledOnTime >= 1600){
ledNowTime = ledStartTime;
leftLedState = 0;
}
}
}

}
// This code runs whenFrobo see line on the right IR diode.
void ledPattern3(){
if (lightMode == 1 && lineDetectRight == 1){
//We will light up left Led in this mode and blink right.
digitalWrite(leftLed, HIGH);
//define ledOnTime.

ledOnTime = ledNowTime - ledStartTime;

if (rightLedState == 0){
ledStartTime = millis();
digitalWrite(rightLed, HIGH);
tone(0, 330);
rightLedState = 1;
}
// This code lights up left Led for 1500 mili seconds (1.5 seconds)
if (leftLedState == 1 ){
ledNowTime = millis();
if (ledOnTime >= 1500){
digitalWrite(rightLed, LOW);
noTone(0);
rightLedState = 2;
}
}
if (rightLedState == 2 ){
if (ledOnTime >= 1600){
ledNowTime = ledStartTime;
rightLedState = 0;
}
}
}

}

// This code runs when light level goes below normal.
void ledPattern4(){
if (lightMode == 0){
//define ledOnTime.

ledOnTime = ledNowTime - ledStartTime;

if (leftLedState == 0&& rightLedState == 0){
ledStartTime = millis();
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, HIGH);
tone(0, 31);

leftLedState = 1;
rightLedState = 1;
}
// This code lights up both Led for 100 mili seconds.
if (leftLedState == 1 && rightLedState == 1 ){
ledNowTime = millis();
if (ledOnTime >= 100){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
noTone(0);
// Let us sound the buzzer using tone() function.
leftLedState = 2;
}
}
//THis code keep Leds off for 80 mili seconds.
if (leftLedState == 2 && rightLedState == 2){
if (ledOnTime >= 180){
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, HIGH);
tone(0, 31);
leftLedState = 3;
rightLedState == 3;
}
}
//Keep Leds on for 100 ms.
if (leftLedState == 3 && rightLedState == 3 ){
if (ledOnTime >= 280){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
noTone(0);
leftLedState = 4;
rightLedState == 4;
}
}
//Keeps Leds off for 500 ms to create a Heartbeat kind of blinking effect.
if (leftLedState == 4 && rightLedState == 4 ){
if (ledOnTime >= 780){
digitalWrite(leftLed, HIGH);
digitalWrite(rightLed, HIGH);
tone(0, 31);
leftLedState = 5;
rightLedState == 5;
}
}
if (leftLedState == 5 && rightLedState == 5 ){
if (ledOnTime >= 880){
digitalWrite(leftLed, LOW);
digitalWrite(rightLed, LOW);
noTone(0);
leftLedState = 6;
rightLedState == 6;
}
}
if (leftLedState == 6 && rightLedState == 6 ){
if (ledOnTime >= 1000){

ledNowTime = ledStartTime;
leftLedState = 0;
rightLedState == 0;
}
}
}

}