# Case 23: Face-tracking with TPBot

## Purpose
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- Build a face-tracking TPBot with the Smart AI Lens.

## Materials required
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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_20_01.png)

- 1 x  [AI Lens](https://shop.elecfreaks.com/products/elecfreaks-smart-ai-lens-kit?_pos=1&_sid=068025047&_ss=r)

![](./images/TPBot_tianpeng_case_20_02.png)





## Hardware Connections
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Connect the AI Lens to the IIC port on TPBot. 

![](./images/TPBot_tianpeng_case_20_03.png)

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


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

![](./images/TPBot_tianpeng_case_20_04.png)

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

![](./images/TPBot_tianpeng_case_20_05.png)

- We need to add a package for programming the AI Lens kit. Click "Extensions" in the bottom of the drawer and seach with `https://github.com/elecfreaks/pxt-PlanetX-AI` in the dialogue box to download it.  

![](./images/TPBot_tianpeng_case_20_06.png)



### Sample Code

- Initialize the AI lens kit in the On start brick and switch its function to face recognition. 

![](./images/TPBot_tianpeng_case_23_07.png)

- In forever brick, get an image from the AI lens and adjust TPBot' direction by the face recognized in the lens. 

![](./images/TPBot_tianpeng_case_23_08.png)

- Complete code:

![](./images/TPBot_tianpeng_case_23_09.png)



### Reference
- Link: [https://makecode.microbit.org/_i4aLd1MvADLU](https://makecode.microbit.org/_i4aLd1MvADLU)

- You may also download it directly here:

<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:_i4aLd1MvADLU" frameborder="0" sandbox="allow-popups allow-forms allow-scripts allow-same-origin"></iframe></div>  



## Python Programming
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Add TPBot extension: [https://www.elecfreaks.com/learn-cn/microbitKit/TPbot_tianpeng/TPbot-python.html](https://www.elecfreaks.com/learn-cn/microbitKit/TPbot_tianpeng/TPbot-python.html)

Add AI Lens extension: [https://www.elecfreaks.com/learn-cn/microbitplanetX/ai/Plant-X-EF05035-python.html](https://www.elecfreaks.com/learn-cn/microbitplanetX/ai/Plant-X-EF05035-python.html)

### Code

```
# Add your Python code here. E.g.
from microbit import *
from AILens import *
from TPBot import *

tp = TPBOT()
ai = AILENS()
# Set the function of AI Lens in face recognition
ai.switch_function(Face)

while True:
    # Get an image
    ai.get_image()

    buff = ai.get_face_data()
    # "buff[0]"means the X coordinates data of the face detected in AI lens
    i = buff[0]
    if ( i < 80):
        tp.set_motors_speed(-30,0)  
    elif ( i > 144):
        tp.set_motors_speed(0,-30)
    else:
        tp.set_motors_speed(0,0)
```

### Result

The TPBot changes its heading direction in accordance with the face the AI Lens detects. 

## Exporation
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## FAQ
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Q: TPBot doesn't work with the sample code.  
A: It is probably due to the lack of battery power, please try adding the speed of the TPBot or replacing with new batteries.   
Q: The AI Lens is not working,  and it does not go to the function page with the sample code.   
A: Please try replacing with new batteries. 

## Relevant File
---