12. Case 11: Line-tracking Car

12.1. Introduction

To build a car that could drive along with the black line with a micro:bit.

../../_images/case_11_01.png

12.2. Quick Start


Materials Required


Nezha expansion board × 1

micro:bit × 1

Line-tracking sensor × 1

Motors × 2

RJ11 wires × 1

Bricks details

../../_images/Bricks_case_11.png

Build the body parts of the car

../../_images/case_10_02.png

Line-tracking module build-up

../../_images/case_11_03.png

Connection Diagram


  • Connect the line-tracking sensor to J1, the two motors to M1&M4 on the Nezha expansion board as the picture shows.

../../_images/case_11_04.png

Assembly

  • Build a device as the picture shows:

../../_images/case_11_05.png

../../_images/case_11_06.png

../../_images/case_11_07.png

../../_images/case_11_08.png

../../_images/case_11_09.png

../../_images/case_11_10.png

../../_images/case_11_11.png

../../_images/case_11_12.png

../../_images/case_11_13.png

../../_images/case_11_14.png

Video reference: https://youtu.be/N2w01pGaj30

12.3. MakeCode Programming


Step 1

Click “Advanced” in the MakeCode to see more choices.

../../_images/case_01_10.png

For programming, we need to add a package: click “Extensions” at the bottom of the MakeCode drawer and search with “PlanetX” in the dialogue box to download it.

../../_images/case_01_11.png

For programming, we need to add a package: click “Extensions” at the bottom of the MakeCode drawer and search with “nezha” in the dialogue box to download it.

../../_images/case_03_09.png

Notice: If you met a tip indicating that some codebases would be deleted due to incompatibility, you may continue as the tips say or create a new project in the menu.

Step 2

Code as below:

../../_images/case_11_15.png

Reference

Link:https://makecode.microbit.org/_MbaX4mTEmHmf

You may also download it directly below:

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Result

  • The car drives along with the black line.