The next module to take a look at is quite often entitled 4-CHANNEL LINE TRACKER SENSOR, thats exactly what it does the module consists of a main module and 4 little sensor/reciever modules that connect via a 3 pin cable
here is a typical module and cables
The 4-Channel Line Tracker sensor provides an easy way for line tracking. A line sensor is composed of a number cells and each cell is composed of a sender and a receiver. The particularity of this sender/receiver pair is that it sends light that shall be reflected by the line to be detected but not by the eventually opaque background surrounding this line. Any sender/receiver pair that is able to make a difference between a line and the rest of ground (of a different color) can be used in a line sensor.
VCC pin is connected to 5V , GND pin is connected to the GND, S1, S2, S3, and S4 pins are connected to the digital I/O pins 2 – 5 but you can use others
Features
Operating voltage: DC 3.3V-5V
Operating Current:>1A
Operating temperature: -10 C – +50 C
Mounting Hole: M3 screws
Detection distance: 1mm to 60 CM adjustable, the closer the distance,the more stable performance, and white reflection farthest.
Output Interface: 6-wire (1234: signal output, +: positive supply -: ground)
Output signal: TTL level
Schematic
Code
Basic stuff here
[codesyntax lang=”cpp”]
void setup()
{
Serial.begin(9600);
}
void loop()
{
Serial.print(digitalRead(2));
Serial.print(" ");
Serial.print(digitalRead(3));
Serial.print(" ");
Serial.print(digitalRead(4));
Serial.print(" ");
Serial.println(digitalRead(5));
delay(1000);
}
[/codesyntax]
Testing
The sensor module has a HIGH output when its placed over a black line, otherwise its LOW.
Links
You can pick one of these modules up for as little as $2.10
Newest 4-Channel Infrared IR Line Detector Patrol Tracking Sensor Module DC 3.3V-5V Durable Quality Sensors Modules lines