Creative Technologies > Block 4 > Projects > Line Follower

Line Follower

The Line Follower does exactly what the name suggests, it follows a line. Make it go where ever you want by showing the way with a 3 cm wide, black line.

Materials

  • 1 Arduino Uno board
  • 1 Basic Education shield
  • 1 IR Array
  • 2 continuous rotation servos
  • 4 black jumper wires
  • 8 coloured jumper wires
  • 2 power connectors (One without the plug but with two loose wires)
  • 1 4 AA battery pack
  • 1 9V battery
  • 4 AA batteries
  • 1 Line follower kit
  • 1 metal ball

Instructions

  1. Attach the shield onto the top of the Arduino board.
  2. Attach one servo on each side of the line follower.
  4. Assemble the ball piece on the middle part of the line follower.
  5. Connect five jumper wires to 5V, GND, IR1, IR2, and IR3 of the IRArray.
  6. Put the jumper wires through the front hole of the middle base and then finish assembling the main body.
  7. Connect the loose wires of the IRArray. 5V to 5V, GND to GND, IR1 to A1, IR2 to A2, IR3 to A3.
  8. Using 3 jumper wires, connect the left servo. The black wire to GND, the white wire to digital pin 10,  and the red wire to the bread board.
  9. Using 3 jumper wires, connect the right servo. The black wire to GND, the white wire to digital pin 9,  and the red wire to the bread board.
  10. Connect the Arduino board to the computer and upload example LineFollower.
  11. Connect the 4 AA battery pack. The black wire to GND and the red wire to the two servo’s power wires on the breadboard.
  12. Place the Arduino and shield on top of the Line Follower and connect the 9V battery to the Arduino.

Code

You can find the code in File -> Examples -> BasicEducationSheild-> Robots-> LineFollower



How it works


The IR sensors in the IRArray can detect black and white. By using the command readLine() we get a value from -100 to 100 representing the direction the line is heading. This value is then used to tell the wheels what direction to go by writing wheels.follow(direction).


Troubleshooting


    

  1. Refer to the illustration and double check your connections. Make sure the shield and wires are firmly connected.
    2. 

  2. Motors are not working? See the reference about how to debug servo motors used as wheels.
    3. 

  3. Debug the IRArray, see the IRArray reference.
    4. 



Experiment further


    

  • Print a track and build obstacles for the robot. If the obstacles are too difficult, see if there is a way to improve the robots performance by modifying the wheels
    • 

  • Make the robot react in some way when it “sees” only white. That is, when it has lost the track of the black line.
    •