# Case 20: Road Indicator for TPBot with AI Lens

## Purpose
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- Guide the TPBot via the AI Lens to drive by the road indicators. 

## 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 cards recognition. 

![](./images/TPBot_tianpeng_case_20_07.png)

- In forever brick, get an image from the AI lens, if the image contains the traffic signals of driving forward, set the TPBot to drive at the speed of 40%. 

![](./images/TPBot_tianpeng_case_20_08.png)

- If the image says turn left, set the TPBot to turn left at the speed of 30% for 0.5s and keep driving forward. As the AI Lens has three buffer zones, here we need to repeat collecting image for three times and discard to clear the buffer. 

![](./images/TPBot_tianpeng_case_20_09.png)

- If the image says turn right, set the TPBot to turn right at the speed of 30% for 0.5s and keep driving forward. As the AI Lens has three buffer zones, here we need to repeat collecting image for three times and discard to clear the buffer. 

![](./images/TPBot_tianpeng_case_20_10.png)

- If the card says stop, stop the TPBot immediately. 

![](./images/TPBot_tianpeng_case_20_11.png)

- Complete code:

![](./images/TPBot_tianpeng_case_20_12.png)


### Reference
- Link: [https://makecode.microbit.org/_c5tFg4d3RRsF](https://makecode.microbit.org/_c5tFg4d3RRsF)

- 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:_c5tFg4d3RRsF" 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

```
from microbit import *
from AILens import *
from TPBot import *

tp = TPBOT()
ai = AILENS()
# Set the function of AI Lens in cards recognition
ai.switch_function(Card)
while True:
    # Get an image
    ai.get_image()
    if (ai.get_card_content() == "Forward"):
        tp.set_motors_speed(40,40)
    if (ai.get_card_content() == "Turn left"):
        tp.set_motors_speed(0,30)
        sleep(1000)
        tp.set_motors_speed(40,40)
        # Repeat getting images for three times to clear the buffer zones
        i = 0
        while i < 3:
          ai.get_image()
          i += 1
    if (ai.get_card_content() == "Turn right"):
        tp.set_motors_speed(30,0)        
        sleep(1000)
        tp.set_motors_speed(40,40)
         # Repeat getting images for three times to clear the buffer zones
        i = 0
        while i < 3:
          ai.get_image()
          i += 1
    if (ai.get_card_content() == "Stop"):
        tp.set_motors_speed(0,0)
   
```

### Result

The TPBot acts as the cards indicate, if the card contains moving forward signal, it drives forward; if it is turning left signal, the TPBot turns left and goes forward; if it is turning right signal, the TPBot turns right and goes forward; if it is stop signal, the TPBot stops moving. 

## Exporation
---


## 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
---