This lesson will show you how to program the mBot to avoid obstacles. It will then show you how test your program on the mBot.

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

1. Assembled mBot from Lesson 1
2. USB Cable
3. Styrofoam Blocks that are at least 5in tall and 2in thick

1. Open the mBlock app on your computer
   
   

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

   

2. Click on the add button on the Devices tab
   
   

   You can also click the 'X' for the CyberPi device since it won't be used

   

3. Select the mBot and click the OK button
   
   

   

4. Click the Upload button under the Mode Switch section
   
   

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

   

5. Click the Events selector and drag the “when mBot(mCore) starts up” block to the coding pane
   
   

   

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

   

7. Click the Sensing selector and drag the “when on-board button pressed?” block to the coding pane and snap it into the “wait until < >” block
   
   

   This allows you to control when the mBot starts running the obstacle avoidance after you power it on

   

8. 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 turn the mBot power off

   

9. Drag the “if < > then else” block to the coding pane and snap it inside the forever block
   
   

   

10. Click the Operators selector and drag the “( ) < 50” block to the coding pane and snap it into the if - then block
    
    

    

11. Click the Sensing selector and drag the “ultrasonic sensor port 3 distance (cm)” block to the coding pane and snap it into the “( ) < 50” block
    
    

    

12. Change the “50” to “10” in the “( ) < 50” block
    
    

    

13. Click the Action selector and drag the “turn right at power 50% for 1 secs” block to the coding pane and snap it inside the top section of the if-then-else block
    
    

    This will cause the mBot to turn right whenever it senses an obstacle within 10cm

    

14. Change the “1” to “0.5” in the “turn right at power 50% for 1 secs” block
    
    

    

15. Drag the “move forward at power 50%” block to the coding pane and snap it inside the bottom section of the if-then-else block
    
    

    This will cause the mBot to move forward whenever it does not sense an obstacle within 10cm

    

16. Connect the USB cable to the mCore mainboard on the mBot and plug the cable into your computer
17. Slide the power switch on the mCore mainboard on the mBot to the ON position and click the Connect button
    
    

    

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

    

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

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

1. Place some of the styrofoam blocks on the floor
2. Place the mBot on the floor and slide the power switch on the mCore mainboard on the mBot to the ON position
3. Press the black button on the front left of the mCore mainboard on the mBot to start the mBot moving
4. When you're finished watching the mBot avoid obstacles, pick it up and slide the power switch on the mCore mainboard to the OFF position

Return to Main mBot page