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.

Step 1: Materials You Need

You will need:

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

Step 2: Schematic

Step 3: Setup

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.

Step 4: Code

#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);

}

Step 5: Check the Video to Know More