# Case 02: Line-following Cars

## Purpose
---
To make a line following car. 
 
![](./images/case-02-01.png)

## Link
---
[micro:bit Wonder Building Kit](https://shop.elecfreaks.com/products/elecfreaks-micro-bit-32-in-1-wonder-building-kit-without-micro-bit-board?_pos=5&_sid=2094afd2f&_ss=r)

## Materials Required
---
![](./images/case-02-02.png)

Video link:
[https://youtu.be/J2QKDKnTklw](https://youtu.be/J2QKDKnTklw)



## Bricks build-up
---


![](./images/step-case-02-01.png)

![](./images/step-case-02-02.png)

![](./images/step-case-02-03.png)

![](./images/step-case-02-04.png)

![](./images/step-case-02-05.png)

![](./images/step-case-02-06.png)

![](./images/step-case-02-07.png)

![](./images/step-case-02-08.png)

## Installation Mthods of Hardwares

Install the dual-line tracking sensor with the bricks. 

![](./images/Wonder-Building-Kit-step-line-following.png)

## Hardware Connection

Connect two [motors](https://www.elecfreaks.com/geekservo-motor-2kg-compatible-with-lego.html) to M1 and M2, the [dual line-following](https://www.elecfreaks.com/octopus-2-channel-tracking-module.html) sensor to P1 and P2 ports on [Wukong breakout board](https://www.elecfreaks.com/wukong-board-with-lego-holder-for-micro-bit.html). 

![](./images/Wonder-Building-Kit-case-02-06.png)


## Software Platform
---
[MakeCode](https://makecode.microbit.org/)

## Coding
---
### Add extensions
Click "Advanced" in the MakeCode to see more choices.
 
![](./images/case-01-03.png)

Search with Wukong in the dialogue box to download it. 

![](./images/case-01-04.png)
 

### Program
 
![](./images/case-02-05.png)

Link:[https://makecode.microbit.org/_azffEJVztHiW](https://makecode.microbit.org/_azffEJVztHiW)

### Result

The car moves along with the maps at a uniform speed, it will keep its speed and directions if it deviates from the black line until it goes back.