This lesson will show you how to program the mBot Neo to follow a line. It will then show you how test your program on the mBot Neo.

The parts below are required to complete this lesson. Note that all parts are included in the mBot Neo kit that can be purchased on Amazon.

1. Assembled mBot Neo from Lesson 1
2. USB Cable
3. Line following paper

1. Connect the USB cable to the CyberPi on the mBot Neo and plug the cable into your computer
   
   

   This will charge up your mBot Neo while you create the program

2. Open the mBlock app on your computer
   
   

   You can download the mBlock app from mBlock Download if it isn't already installed

   

3. Click on the Extension button
   
   

   

4. Click the Add button under the mBot2 shield
   
   

   

5. Click on the Extension button
   
   

   

6. Click the Add button under the Quad RGB Sensor
   
   

   

7. Click the Upload button under the Mode Switch section
   
   

   This allows you to write your program without having the mBot Neo connected to your computer

   

8. Click the Events selector and drag the “when CyberPi starts up” block to the coding pane
   
   

   

9. Click the Display selector and drag the “print makeblock and move to a newline” block to the coding pane and snap it to the bottom of the stack
   
   

   

10. Change the “makeblock” to “Press B to start line following and A to stop” in the “print makeblock and move to a newline” block
    
    

    

11. Click the Control selector and drag the “wait until < >” block to the coding pane and snap it to the bottom of the stack
    
    

    

12. Click the Sensing selector and drag the “button A pressed?” block to the coding pane and snap it into the “wait until < >” block
    
    

    This allows you to control when the mBot Neo starts running the line following after you power it on

    

13. Change the “A” to “B” in the “when button A pressed” block
    
    

    

14. Click the Variables selector and click the Make a Variable button to create the following variables for all sprites
    
    

    This will allow your program to store information that it needs and change it as it runs

    

    1. base_power
       
       

       

    2. kp
       
       

       

    3. left_power
       
       

       

    4. right_power
       
       

       

15. Drag the “set base_power to 0” block to the coding pane and snap it to the bottom of the stack
    
    

    

16. Change the “0” to “30” in the “set base_power to 0” block
    
    

    

17. Drag the “set base_power to 0” block to the coding pane and snap it to the bottom of the stack
    
    

    

18. Change the “base_power” to “kp” and the “0” to “0.5” in the “set base_power to 0” block
    
    

    

19. Click the Control selector and drag the “forever” block to the coding pane and snap it to the bottom of the stack
    
    

    This will allow your program to keep running until you press the A button on the CyberPi

    

20. Click the Variables selector and drag the “set base_power to 0” block to the coding pane and snap it into the forever block
    
    

    

21. Change the “base_power” to “left_power” in the “set base_power to 0” block
    
    

    

22. Click the Operators selector and drag the “( ) - ( )” block to the coding pane and snap it into the “set left_power to 0” block
    
    

    

23. Drag the “( ) * ( )” block to the coding pane and snap it into the right side of the “set left_power to ( ) - ( )” block
    
    

    

24. Click the Variables selector and drag the “base_power” block to the coding pane and snap it into the left side of the “set left_power to ( ) - ( ( ) * ( ) )” block
    
    

    

25. Drag the “kp” block to the coding pane and snap it into the middle of the “set left_power to (base_power) - ( ( ) * ( ) )” block
    
    

    

26. Click the Quad RGB Sensor selector and drag the “quad rgb sensor 1 deviation (-100-100)” block to the coding pane and snap it into the right side of the “set left_power to (base_power) - ( (kp) * ( ) )” block
    
    

    

27. Click the Variables selector and drag the “set base_power to 0” block to the coding pane and snap it into the forever block
    
    

    

28. Change the “base_power” to “right_power” in the “set base_power to 0” block
    
    

    

29. Click the Operators selector and drag the “( ) * ( )” block to the coding pane and snap it into the “set right_power to 0” block
    
    

    

30. Drag the “( ) + ( )” block to the coding pane and snap it into the right side of the “set right_power to ( ) * ( )” block
    
    

    

31. Drag the “( ) * ( )” block to the coding pane and snap it into the right side of the “set right_power to ( ) * ( ( ) + ( ) )” block
    
    

    

32. Change the first of the “set right_power to ( ) * ( ( ) + ( ( ) * ( ) ) )” block to “-1”
    
    

    

33. Click the Variables selector and drag the “base_power” block to the coding pane and snap it into the second of the “set right_power to (-1) * ( ( ) + ( ( ) * ( ) ) )” block
    
    

    

34. Drag the “kp” block to the coding pane and snap it into the third of the “set right_power to (-1) * ( (base_power) + ( ( ) * ( ) ) )” block
    
    

    

35. Click the Quad RGB Sensor selector and drag the “quad rgb sensor 1 deviation (-100-100)” block to the coding pane and snap it into the right side of the “set right_power to (-1) * ( (base_power) + ( (kp) * ( ) ) )” block
    
    

    

36. Click the mBot2 Chassis selector and drag the “encoder motor EM1 rotates at 50% power, encoder motor EM2 rotates at 50% power” block to the coding pane and snap it into the forever block
    
    

    

37. Click the Variables selector and drag the “left_power” block to the coding pane and snap it into the left section of the “encoder motor EM1 rotates at 50% power, encoder motor EM2 rotates at 50% power” block
    
    

    

38. Drag the “right_power” block to the coding pane and snap it into the right section of the “encoder motor EM1 rotates at left_power% power, encoder motor EM2 rotates at 50% power” block
    
    

    

39. Click the Events selector and drag the “when button A pressed” block to an empty area of the coding pane
    
    

    

40. Click the Control selector and drag the “restart CyberPi” block to the coding pane and snap it to the bottom of the when button A pressed block
    
    

    This will cause the mBot Neo to restart things when when the A button is pressed no matter what is happening in the forever loop

    

41. Change the name of the program in the upper left to “LineFollow”
    
    

    

42. Slide the power switch on the mBot2 Shield to the ON position and click the Connect button
    
    

    

43. Click the Upload button and wait for the upload to complete
    
    

    

44. Slide the power switch on the mCore mainboard on the mBot to the OFF position and disconnect the USB cable from the mBot Neo

Follow the steps below to test out the program you just created

1. Place the line following map on the floor
2. Place the mBot on the line and slide the power switch on the mBot2 Shield on the mBot Neo to the ON position
3. Press the B button on the CyberPi to start the mBot Neo moving
4. When you're finished watching the mBot Neo follow the line, press the A button
5. Change the initial values of the base_power and kp variables to see how they change the mBot Neo line following

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