# Case15: Speed Adjustable TPBot

## Purpose
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- Adjust the speed of the TPBot with the potentiometer. 

## Material
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- 1 x [TPBot](https://shop.elecfreaks.com/products/elecfreaks-micro-bit-tpbot-car-kit-without-micro-bit-board?_pos=1&_sid=f32828112&_ss=r)


![](./images/TPBot_tianpeng_case_01_01.png)


## Hardware connection
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Connect potentiometer to port 1 on TPBot. 


![](./images/TPBot_tianpeng_case_15_02.png)



## Software
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[MicroSoftmakecode](https://makecode.microbit.org/#)


## Programming
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Click "Advanced" to see more choices in the MakeCode drawer. 

![](./images/TPBot_tianpeng_case_01_02.png)

- We need to add a package for programming. Click "Extensions" in the bottom of the drawer and search with "tpbot" in the dialogue box to download it.  

![](./images/TPBot_tianpeng_case_01_03.png)

- We need to add a package for programming. Click "Extensions" in the bottom of the drawer and seach with "PlanetX" in the dialogue box to download it.  

![](./images/TPBot_tianpeng_case_15_03.png)

### Sample

- Drag the show icon brick into on start. 
- In forever brick, map the returned value of the potentiometer from 0~1023 to 0~100, and set the mapping value as the speed for the car to move forward. 

![](./images/TPBot_tianpeng_case_15_04.png)


### Link
- Link：[https://makecode.microbit.org/_ArRM71PD6de0](https://makecode.microbit.org/_ArRM71PD6de0)

- You may also download it directly below:

<div style="position:relative;height:0;padding-bottom:70%;overflow:hidden;"><iframe style="position:absolute;top:0;left:0;width:100%;height:100%;" src="https://makecode.microbit.org/#pub:_ArRM71PD6de0" frameborder="0" sandbox="allow-popups allow-forms allow-scripts allow-same-origin"></iframe></div>  

### Conclusion

- After powering on, the speed of the TPBot could be adjusted by the potentioneter. 


## Exploration
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## FAQ
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Q: While operating this case, why the car might not work properly?  
A: It might be the low power of the batteries, please try adding the value of TPBot's speed and test again. 

## Relevant File
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