* BUGGY SAMPLE CODE
--------------------------------------------------------------
//SETUP LIBRARY

#include <Servo.h> 
Servo motor_Left;  // setup left motor 
Servo motor_Right; // setup right motor
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// DEFINE PINS

const in motor_Left_PIN = 10;
const in motor_Right_PIN = 9;
const in greenLed_PIN = 2;
const in Pot_PIN = A0;

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// PID CONTROLS VARIABLES

float kp = 1; // Proportional gain
float Ki =1;  // Integral gain
float kd = 1; // Derivative gain 
float previousError = 0; 
float integralError = 0;

---------------------------------------------------------------

// DEFINE VARIABLES FOR POT ANGLE MEASURMENT

const int angleSensorPin = A0;
const float zeroAngleVoltage = 2.5; // Voltage when the buggy is level
const float angleConversionFactor = 180.0 / 5.0; // Conversion factor from voltage to degrees

----------------------------------------------------------------

// DEFINE VARIABLES FOR SCANNING TIMER

bool scanning = false;
unsigned long scanStartTime = 0;
const unsigned long scanDuration = 5000; // 5 seconds in milliseconds

-----------------------------------------------------------------


void setup() {

  // START SERIAL COMMUNICATION

  Serial.begin(9600);

  // SETUP PIN MODES

  pinMode(motor_Left_PIN, OUTPUT);
  pinMode(motor_Right_PIN, OUTPUT);
  pinMode(greenLed_PIN, OUTPUT);

  // SETUP MOTORS 

  motor_Left.attach(motor_Left_PIN); //Attach the left motor controller
  motor_Right.attach(motor_Right_PIN); //Attach the right motor controller

  // INTIALIZE MOTORS

  motor_Left.writeMicroseconds(1000); 
  motor_Right.writeMicroseconds(1000);

  // START LED

  digitalWrite(greenLed_PIN, HIGH);

  analogWrite(motor_Left_PIN, 60); // sending zero signal.
  analogWrite(motor_Right_PIN, 60); // sending zero signal.

}

void loop() {

  motor_Left.write(180); //MOTOR OFF (use 180 for full power)
  motor_Right.write(180); //MOTOR OFF (use 180 for full power)

  ------------------------------------------------------------------

  // READ CURRENT ANGLE FRON POT SENSOR

  float voltage = analogRead(angleSensorPin) * (5.0 / 1023.0);
  float angle = (voltage - zeroAngleVoltage) * angleConversionFactor;

  ------------------------------------------------------------------

  // CALCULATE ERROR AND PID SIGNAL

  float error = -angle; // set target angle to zero
  integralError += error;
  float derivativeError = error - previousError;
  previousError = error;
  float motorControlSignal = kp * error + ki * integralError + kd * derivativeError;

  --------------------------------------------------------------------

  // CONTROL MOTOR SIGNAL INTO MOTOR VALUES
  motor_Left.writeMicroseconds(1500 - motorControlSignal); //Control the left motor
  motor_Right.writeMicroseconds(1500 + motorControlSignal); //Control the right motor

  ---------------------------------------------------------------------

  // SEND ZERO POWER TO MOTORS AFTER 11 METERS
  motor_Left.write(60); //MOTOR OFF
  motor_Right.write(60); //MOTOR OFF

}