# Case 11: Line-tracking Car ## Introduction This is a line tracking car, we can use black electrical tape to paste a track on the white plane, and then make the car drive according to the preset trajectory. ![](./images/case_11_01.png) ## Quick Start ### Materials Required Nezha expansion board × 1 micro:bit × 1 Line-tracking sensor × 1 Motors × 2 RJ11 wires × 1 ***Tips: You may need to purchase [Nezha Inventor's Kit](https://shop.elecfreaks.com/products/elecfreaks-micro-bit-nezha-48-in-1-inventors-kit-without-micro-bit-board?_pos=2&_sid=ed1b6fbd2&_ss=r) if you want all the above compoents.*** ### 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/case11-04.png) ### Assembly Steps ![](./images/case_step_11_01.png) ![](./images/case_step_11_02.png) ![](./images/case_step_11_03.png) ![](./images/case_step_11_04.png) ![](./images/case_step_11_05.png) ![](./images/case_step_11_06.png) ![](./images/case_step_11_07.png) ![](./images/case_step_11_08.png) ![](./images/case_step_11_09.png) ![](./images/case_step_11_10.png) ![](./images/case_step_11_11.png) ![](./images/case_step_11_12.png) ![](./images/case_step_11_13.png) ![](./images/case_step_11_14.png) ![](./images/case_step_11_15.png) ![](./images/case_step_11_16.png) ![](./images/case_step_11_17.png) ![](./images/case_step_11_18.png) ![](./images/case_step_11_19.png) ![](./images/case_step_11_20.png) ![](./images/case_step_11_21.png) ## 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](https://makecode.microbit.org/_MbaX4mTEmHmf) You may also download it directly below:
### Result The car drives along with the black line. ![](./images/case-gif-11.gif)