14. case 04 Here comes the police

14.1. Our Goal

• To change the Ring:bit car to a police car.

14.2. Requiered Materials

• 1 x Ring:bit Car

14.3. Hardware Connect

• Connect the left wheel servo to P1 of the Ring:bit expansion board and the right wheel servo to P2.
• Connect the ring:bit car special expansion board to the P0.
• Slide the clip switch of the special expansion board to the Rainbow LED.

14.4. Software

makecode

14.5. Coding

Step 1

• Click on “Advanced” in the MakeCode Drawer to see more code sections.

• Search for “ringbitcar” and click on the ring:bit car package to add it to your project. (As below picture)

Note： If you get a warning telling you some packages will be removed because of incompatibility issues, either follow the prompts or create a new project in the Project file menu.

Step 2

• Snap the block set left wheel at pin P1 right wheel at pin P2 to the On start block. The port number is based on the actual servo connection port.
• Go straight at full speed.
• Set the 2 Rainbow LED of the P0 to RGB color.

Step 3

• Within the forever block, snap below blocks in line:
• show color red block.
• pause(ms) 100 block.
• show color blue block.
• pause(ms) 100 block.

Program

Program Link：https://makecode.microbit.org/_AvMC6j86A5ym

If you don’t want to type these code by yourself, you can directly download the whole program from the link below:

14.6. Result

• The car goes straigt at full speed at red and blue flash.

14.7. Think

• How can you make youe car at yellow and white flash?

14.8. Questions

14.9. More Information