COLOR
PROBING LINE FOLLOWER
Introduction
Hey! I just made a line following robot. This robot not
only follows the black line but can also detect other colors. There is a RGB
LED which glows in the color on which the robot is placed. I used the arduino
board for this project for simplicity; you can use any other board you are
familiar.
Pre requisite
You should be little familiar with some micro controller.
You should have some knowledge of infrared sensors and some fundamentals of
electronics.
Components
Arduino board, Color sensor, Infrared sensor, Breadboard,
Jumpers, Chassis, Wheels, Motor(150 rpm), Castor wheel, Power supply, L293D
module, RGB LED Multimeter, some Nuts
and Screws.
Step1
The first step is to make the connections of arduino with
infrared sensor. Before we move to the connections lets first talk about
infrared sensors. These sensors work on very simple principal. There is an
infrared LED which emits the lights and if the surface is white the light will
be reflected back and can be detected by photo diode. This sensor has three
pins, 2 for power supply and one for output. This output pin can be connected
to any general purpose pin of arduino. The sensor also has to potentiometer to
calibrate the proximity range.
Step2
The
connection of motor driver and arduino. L293D is used to amplify the signals
coming from arduino. The 3 upper most pins of the module are power supply pins.
The control signal pins are connected to any general purpose pins of arduino.
PWM pins can only be connected to analog pins of the board.
Step 3
The connection of arduino and color sensor. I used TCS3200 module. You can download the
data sheet from this link http://www.mouser.com/catalog/specsheets/TCS3200-E11.pdf this sensor is very simple to use. The
light sensor works by throwing a white light at an object and then recording
the reflected color, it can read the intensity. Through red, green and blue
color filters the photodiode converts the amount of light to current and this
can be read by arduino. The connections of arduino board and RGB sensor can be
easily done. The s2 and s3 pins are select lines. By selecting the values of s2
and s3 the value of particular color can be read. S0 and gnd are ground pins. S1 and vcc are 5v. Pin OE is active low.
The following table is about the selecting lines to read
particular color.
S2
|
S3
|
Color
|
LOW
|
LOW
|
Red
|
LOW
|
HIGH
|
Green
|
HIGH
|
HIGH
|
Blue
|
The out pin of the module is used to read the value of three
colors.
Three more pins of arduino
will be required to connect with RGB LED with particular resistance. Make sure
these pins should be connected to the PWM pins of arduino. As we know there is
no color which is perfect red , green or blue. So I programmed the sensor to
read all the three colors and write that particular value of every color on RGB led by making necessary calculations.
Step 4
Programming
The code is very simple. I
have written all the necessary comments to make it more easy to understand.
int s2=7, s3=8;//select lines
int outpin=4;
int r,g,b;
int rpin=11;
int bpin=9;
int gpin=10;
unsigned int pulsewidth;
void setup()
{
Serial.begin(9600);//to activate serial
monitor
pinMode(s2,OUTPUT);//select line
pinMode(s3,OUTPUT);//select line
pinMode(outpin,INPUT);//output from rgb
sensor
pinMode(rpin,OUTPUT);//output to red pin
pinMode(bpin,OUTPUT);//output to blue pin
pinMode(gpin,OUTPUT);//output to green pin
pinMode(2,INPUT);//right sensor
pinMode(3,INPUT);//left sensor
pinMode(5,OUTPUT);//right forward
pinMode(6,OUTPUT);//right backward
pinMode(13,OUTPUT);//left forward
pinMode(7,OUTPUT);//left backward
}
void
loop()
{
int a,b;
a=(digitalRead,3 );//right
b=(digitalRead,4);//left
if(a==1 && b==1)//forward
{
digitalWrite(5,HIGH);
digitalWrite(13,HIGH);
digitalWrite(6,LOW);
digitalWrite(7,LOW);
}
if(a==0 && b==1)//right turn
{
digitalWrite(6,HIGH);
digitalWrite(13,HIGH);
digitalWrite(5,LOW);
digitalWrite(7,LOW);
}
if(a==1 && b==0)//left turn
{
digitalWrite(7,HIGH);
digitalWrite(5,HIGH);
digitalWrite(13,LOW);
digitalWrite(6,LOW);
}
if(a==0 && b==0)//forward
{
digitalWrite(13,HIGH);
digitalWrite(5,HIGH);
digitalWrite(6,LOW);
digitalWrite(7,LOW);
}
//reading red
digitalWrite(s2,LOW);
digitalWrite(s3,LOW);
pulsewidth = pulseIn(outpin, LOW);
r = pulsewidth/25. -1;
r = (4080-r);
//reading green
digitalWrite(s2,HIGH);
digitalWrite(s3,HIGH);
pulsewidth = pulseIn(outpin,LOW);
g = pulsewidth/25. -1;
g = (4080-g);
//reading blue
digitalWrite(s2,LOW);
digitalWrite(s3,HIGH);
pulsewidth = pulseIn(outpin,LOW);
b = pulsewidth/25. -1;
b = (4080-b);
if(r>g
&& r>b && g>b)
{
r=r;
g=g/3;
b=b/7;
}
else
if(r>g && r>b && b>g)
{
r=r;
b=b/3;
g=g/7;
}
else
if(g>b && g>r && r>b)
{
g=g;
r=r/3;
b=b/7;
}
else
if(g>b && g>r && b>r)
{
g=g;
b=b/3;
g=g/7;
}
else
if(b>g && b>r && r>g)
{
b=b;
r=r/3;
g=g/7;
}
else
if(b>g && b>r && g>r)
{
b=b;
g=g/3;
r=r/7;
}
r=r/16;
g=g/16;
b=b/16;
g=g*0.3;
b=b*0.3;
Serial.print(r);
Serial.print(" ,");
Serial.print(g);
Serial.print(" ,");
Serial.println(b);
analogWrite(rpin,r);
analogWrite(gpin,g);
analogWrite(bpin,b);
THANK YOU
