Line Follower Basic Using Arduino Nano

Line Follower Basic using Arduino Nano is a line follower robot with arduino nano controller which using 6 line sensors. This robot is also equipped with PID controller (Proportional Integral Derivative). It makes the robot can navigate well.

You will need:

1. Arduino Nano CH340
2. Line Follower Basic Board
3. Line sensor of Line Follower

Solder the line sensors that have been prepared with and then pair it with IDC socket that is on board of line follower basic arduino nano.

#include <EEPROM.h>

#include <LiquidCrystal_SR.h>

#include <Wire.h>

LiquidCrystal_SR lcd(3,10,2);

#define eepromKp 0

#define eepromSpeed 1

#define eepromKd 2

#define button1 13

#define button2 12

#define button3 1

#define button4 0

#define echo 10

#define trigger 11

#define pwmOne 5

#define inAOne 4

#define inBOne 9

#define pwmTwo 6

#define inATwo 8

#define inBTwo 7

int sensorVal[6];

void setup() {

// put your setup code here, to run once:

pinMode(button1, INPUT_PULLUP);

pinMode(button2, INPUT_PULLUP);

pinMode(button3, INPUT_PULLUP);

pinMode(button4, INPUT_PULLUP);

pinMode(pwmOne, OUTPUT);

pinMode(inAOne, OUTPUT);

pinMode(inBOne, OUTPUT);

pinMode(pwmTwo, OUTPUT);

pinMode(inATwo, OUTPUT);

pinMode(inBTwo, OUTPUT);

Serial.begin(9600);

delay(1000);

pinMode(A0, INPUT);

pinMode(A1, INPUT);

pinMode(A2, INPUT);

pinMode(A3, INPUT);

pinMode(A4, INPUT);

pinMode(A5, INPUT);

lcd.begin(16,2);

lcd.setCursor(0,0);

lcd.print(“`sfe-electronics”);

lcd.setCursor(0,1);

lcd.print(“`LF Basic 6 Sens”);

delay(2000);

lcd.clear();

}

unsigned char Kp = 25;

unsigned char Kd = 9;

unsigned char Ts = 1;

unsigned char max_pwm_ref=125;

int error, last_error, MV,pid_l,pid_r,D,D1,D2,D3,P,Pd, bitSensor;

int Max_MV;

char lcdBuff[16];

void loop() {

Kp = EEPROM.read(eepromKp);

//max_pwm_ref = EEPROM.read(eepromSpeed);

Kd = EEPROM.read(eepromKd);

lcd.setCursor(0,0);

lcd.print(“Kp Speed Kd”);

lcd.setCursor(0,1);

sprintf(lcdBuff,“%3d %3d %3d”,Kp, max_pwm_ref,Kd);

lcd.print(lcdBuff);

if(digitalRead(button3) == LOW)

{

delay(150);

Kp++;

EEPROM.write(eepromKp, Kp);

}

if(digitalRead(button2) == LOW)

{

delay(150);

Kd++;

EEPROM.write(eepromKd, Kd);

}

if(digitalRead(button4) == LOW)

{

while(1)

{

robotRun();

}

}

}

void readSens()

{

sensorVal[0] = digitalRead(A0); sensorVal[1] = digitalRead(A1); sensorVal[2] = digitalRead(A2);

sensorVal[3] = digitalRead(A3); sensorVal[4] = digitalRead(A5); sensorVal[5] = digitalRead(A4);

}

void robotRun()

{

readSens();

bitSensor = ((sensorVal[0]*1)+(sensorVal[1]*2)+(sensorVal[2]*4)+(sensorVal[3]*8)+(sensorVal[4]*16)+(sensorVal[5]*32));

switch(bitSensor)

{

case 0b011111: error = –5; break;

case 0b001111: error = –4; break;

case 0b101111: error = –3; break;

case 0b100111: error = –2; break;

case 0b110111: error = –1; break;

case 0b110011: error = 0; break;

case 0b111011: error = 1; break;

case 0b111001: error = 2; break;

case 0b111101: error = 3; break;

case 0b111100: error = 4; break;

case 0b111110: error = 5; break;

case 0b111111: if(error > 3) {error=6;}

if(error <– 3){error=–6;} break;

}

Max_MV = Kp*5; //limiting the output value of the PID results

//### rumus PID digital

P = Kp * error;

D1 = Kd*8;

D2 = D1 / Ts;

D3 = error – last_error;

D = D2 * D3;

last_error = error;

MV = P + D;

//=======================================//

if(MV>=–Max_MV && MV<=Max_MV) //if the PID output does not exceed the PID output limit value then the robot will run

{ //forward with the right and left PWM settings

pid_l = max_pwm_ref – MV;

pid_r = max_pwm_ref + MV;

if (pid_l < 0) pid_l = 0;

if (pid_l > 255) pid_l = 255;

if (pid_r < 0) pid_r = 0;

if (pid_r > 255) pid_r = 255;

forward(pid_r,pid_l);

}

else if(MV<–Max_MV) //if the PID output is smaller than the PID output limit value the robot will rotate RIGHT

{

turnLeft(200,100);

}

else if(MV>Max_MV) //if the PID output is larger than the PID output limit value the robot will rotate LEFT

{

turnRight(100,200);

}

else

{

forward(pid_r,pid_l);

}

lcd.setCursor(0,0);

sprintf(lcdBuff,“%i%i%i%i%i%i”, sensorVal[0],sensorVal[1],sensorVal[2],sensorVal[3],sensorVal[4],sensorVal[5]);

lcd.print(lcdBuff);

lcd.setCursor(0,1);

sprintf(lcdBuff, “%2d %3d %3d”, error, pid_l, pid_r);

lcd.print(lcdBuff);

}

void forward(int valLeft, int valRight)

{

digitalWrite(inAOne, LOW);

digitalWrite(inBOne, HIGH);

analogWrite(pwmOne, valLeft);

digitalWrite(inATwo, HIGH);

digitalWrite(inBTwo, LOW);

analogWrite(pwmTwo, valRight);

}

void backward(int valLeft, int valRight)

{

digitalWrite(inAOne, HIGH);

digitalWrite(inBOne, LOW);

analogWrite(pwmOne, valLeft);

digitalWrite(inATwo, LOW);

digitalWrite(inBTwo, HIGH);

analogWrite(pwmTwo, valRight);

}

void turnRight(int valLeft, int valRight)

{

digitalWrite(inAOne, LOW);

digitalWrite(inBOne, HIGH);

analogWrite(pwmOne, valLeft);

digitalWrite(inATwo, LOW);

digitalWrite(inBTwo, HIGH);

analogWrite(pwmTwo, valRight);

}

void turnLeft(int valLeft, int valRight)

{

digitalWrite(inAOne, HIGH);

digitalWrite(inBOne, LOW);

analogWrite(pwmOne, valLeft);

digitalWrite(inATwo, HIGH);

digitalWrite(inBTwo, LOW);

analogWrite(pwmTwo, valRight);

}

void stopRun()

{

digitalWrite(inAOne, HIGH);

digitalWrite(inBOne, HIGH);

analogWrite(pwmOne, 0);

digitalWrite(inATwo, HIGH);

digitalWrite(inBTwo, HIGH);

analogWrite(pwmTwo, 0);

}