This lesson will show you how to program the mBot Neo to recognize colors while following 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 color 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 color 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 “40” 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 LED selector and drag the “display” block to the coding pane and snap it to the bottom of the stack
    
    

    This will allow your mBot Neo to display colors on its LEDs

    

20. 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

    

21. Click the My Blocks selector and click the Make a Block button to create the following blocks
    
    

    This will allow you to make your program neater

    

    1. follow_line
       
       

       

    2. detect_colors
       
       

       

    3. start_again
       
       

       

22. Drag the Define blocks in the coding pane to blank areas
    
    

    

23. Drag the “follow_line” block to the coding pane and snap it into the forever block
    
    

    

24. Drag the “detect_colors” block to the coding pane and snap it into the forever block
    
    

    

25. Drag the “start_again” block to the coding pane and snap it into the forever block
    
    

    

26. Click the Variables selector and drag the “set base_power to 0” block to the coding pane and snap it to the bottom of the Define follow_line block
    
    

    

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

    

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

    

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

    

30. 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
    
    

    

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

    

32. 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
    
    

    

33. Click the Variables selector and drag the “set base_power to 0” block to the coding pane and snap it to the bottom of the Define line_following stack
    
    

    

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

    

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

    

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

    

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

    

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

    

39. 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
    
    

    

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

    

41. 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
    
    

    

42. 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 to the bottom of the Define line_following stack
    
    

    

43. 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
    
    

    

44. 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
    
    

    

45. Click the Control selector and drag the “if < > then” block to the coding pane and snap it to the bottom of the Define detect_colors block 4 times
    
    

    

46. Click the Quad RGB Sensor selector and drag the “quad rgb sensor 1 probe (1) R2 detects line?” block to the coding pane and snap it into each of the “if < > then” blocks
    
    

    

47. Change the “(1) R2” to “random” and the “line” to “red” in the top “quad rgb sensor 1 probe (1) R2 detects line?” block
    
    

    

48. Change the “(1) R2” to “random” and the “line” to “yellow” in the second “quad rgb sensor 1 probe (1) R2 detects line?” block
    
    

    

49. Change the “(1) R2” to “random” and the “line” to “green” in the third “quad rgb sensor 1 probe (1) R2 detects line?” block
    
    

    

50. Change the “(1) R2” to “random” and the “line” to “blue” in the bottom “quad rgb sensor 1 probe (1) R2 detects line?” block
    
    

    

51. Click the Audio selector and drag the “play hi” block to the coding pane and snap it into each of the if - then blocks
    
    

    

52. Change the “hi” to “clockwork” in the top three “play hi” blocks
    
    

    The clockwork sound is near the bottom of the list

    

53. Change the “hi” to “iron” in the bottom “play hi” block
    
    

    The iron sound is near the bottom of the list

    

54. Click the LED selector and drag the “display” block to the coding pane and snap it into each of the if - then blocks
    
    

    

55. Click on the LED colors in the top display block and change them all to “red”
    
    

    

56. Click on the LED colors in the second display block and change them all to “yellow”
    
    

    

57. Click on the LED colors in the third display block and change them all to “green”
    
    

    

58. Click on the LED colors in the bottom display block and change them all to “blue”
    
    

    

59. Click the Variables selector and drag the “set base_power to 0” block to the coding pane and snap it into each of the if - then blocks
    
    

    

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

    

61. Change the “0” to “20” in the second “set base_power to 0” block
    
    

    

62. Change the “0” to “10” in the third “set base_power to 0” block
    
    

    

63. Click the Control selector and drag the “if < > then” block to the coding pane and snap it to the bottom of the Define start_again block
    
    

    

64. Click the Sensing selector and drag the “button A pressed?” block to the coding pane and snap it into the “if < > then” block
    
    

    This allows you to start the mBot Neo line following again after it stops

    

65. Change the “A” to “B” in the “if button A pressed then” block
    
    

    

66. Click the Audio selector and drag the “play hi” block to the coding pane and snap it into the if - then block
    
    

    

67. Change the “hi” to “iron” in the “play hi” block
    
    

    The iron sound is near the bottom of the list

    

68. Click the mBot2 Chassis selector and drag the “moves forward 100 cm until done” block to the coding pane and snap it into the if - then block
    
    

    

69. Change the “100” to “5” in the “moves forward 100 cm until done” block
    
    

    

70. Click the LED selector and drag the “display” block to the coding pane and snap it into the if - then block
    
    

    

71. Click the Variables selector and drag the “set base_power to 0” block to the coding pane and snap it into the if - then block
    
    

    

72. Change the “0” to “40” in the “set base_power to 0” block
    
    

    

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

    

74. 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

    

75. Change the name of the program in the upper left to “ColorLineFollow”
    
    

    

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

    

77. Click the Upload Code button and wait for the upload to complete
    
    

    

78. 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 sounds and LED colors to see how they change what the mBot Neo does

Return to Main mBot Neo page