Line Following Robot (Arduino IDE)

Go to https://bitbot.l33t.uk/arduino-ide/ultrasonic-example-arduino-ide for instructions on how to configure Arduino IDE for use with the BBC Micro:bit if you haven’t already. This code builds on the code found at https://bitbot.l33t.uk/arduino-ide/porting-bitbot-code-from-micropython-to-c

The ported code is below. It’s not a complete port I have added a clause when the robot sees 2 black lines it will go backwards. The method below was added to the ported code found here (under a new tab). Create a new tab and name it _01_LineFollower, select the new tab and paste the below code into the IDE.

Simple Line Follower

/*
 * Simple line following algorithm for the 4Tronix Bit:Bot
 * Author David Bradshaw 2018
 */

void followLine()
{
    boolean isLeftLine = detectLine(0);  //Left line detector
    boolean isRightLine = detectLine(1); //Right line detector

    if(isLeftLine == true && isRightLine == true)
    {
        //both sensors can see a line
        setColourRight(32,0,0);
        setColourLeft(32,0,0);
        while (isLeftLine == true && isRightLine == true)
        {
            isLeftLine = detectLine(0);  //Left line detector
            isRightLine = detectLine(1); //Right line detector
            backwards(125);
        }
        delay(350); //carry on going backwards for 350mS
        forwards(0); //Stop bitbot
    }   
    if (isLeftLine == true && isRightLine == false)
    {
        //Line on left hand side
        setColourRight(0,32,0);
        setColourLeft(32,0,0);
        while (isLeftLine == true && isRightLine == false)
        {
            isLeftLine = detectLine(0);  //Left line detector
            isRightLine = detectLine(1); //Right line detector
            left(50);
            delay(50);
        }
        forwards(0);
    }
    else if (isLeftLine == false && isRightLine == true)
    {
        //line on right hand side
        setColourRight(32,0,0);
        setColourLeft(0,32,0);
        while (isLeftLine == false && isRightLine == true)
        {
            isLeftLine = detectLine(0);  //Left line detector
            isRightLine = detectLine(1); //Right line detector
            right(50);
            delay(50);
        }
        forwards(0);
    }
    else if (isLeftLine == false && isRightLine == false)
    {
        //no line detected
        setColourRight(0,32,0);
        setColourLeft(0,32,0);
        forwards(50);
    }
}

I then added the following line in the void loop() method in the tab named _00_programLoop;

Call the above Function

followLine();

Now were using Arduino IDE we have freed up a lot of memory we can write a more complicated line following algorithm. The above algorithm is as simple as it gets for this stuff, in the near future I will add a much more complicated line follower algorithm.

You can download the full code from the resources section or by clicking Bitbot_Lib_LF.