# Case 04: Farmlands Protection Device


##  Introduction
---

- In order to protect the farmlands from people to get in, we can set a farmland protection device. 

##  Function 
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- Detect if there is any people approaching with the PIR sensor and Sonar:bit,  if yes, program to remind people of not coming by lighting on the rainbow LED. 

## Products Link
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- 1 x [microbit Smart Agriculture Kit](https://shop.elecfreaks.com/products/elecfreaks-micro-bit-smart-agriculture-kit-without-micro-bit-board?_pos=2&_sid=2c86b7764&_ss=r)

## Picture
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![](./images/microbit-Smart-Agriculture-Kit-case-01-02.png)

## Hardware Connection
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Connect the Sonar:bit to P1, the PIR sensor to P2 and the rainbow LED to P9 on IoT:bit. 

![](./images/microbit-Smart-Agriculture-Kit-case-04-03.png)

## Software Programming 

---

Click "Advanced" in the MakeCode to see more choices.

![](./images/microbit-Smart-Agriculture-Kit-case-01-04.png)

For programming, we need to add a package: click "Extensions" at the bottom of the MakeCode drawer and search with "iot-environment-kit" in the dialogue box to download it. 

![](./images/microbit-Smart-Agriculture-Kit-case-01-05.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. 

## Program

---

Drag the on start block from the drawer, initialize the strip connecting to P9 with 1 led. 

![](./images/microbit-Smart-Agriculture-Kit-case-04-07.png)

Set to connect the sonar:bit to P1 with unit "cm" and the PIR sensor to P2, save the returned values as the variable "ultrasonic_distance" and the variable "IR" accordingly. 

![](./images/microbit-Smart-Agriculture-Kit-case-04-08.png)

Judge if the variable "ultrasonic_distance" is in the threshold, if yes, judge if the variable "IR" is 1, if yes, set the strip to show red and the buzzer to alarm; or turn the lights off. 

![](./images/microbit-Smart-Agriculture-Kit-case-04-09.png)

If the variable "ultrasonic_distance" is not in the threshold, program to turn off it light. 

![](./images/microbit-Smart-Agriculture-Kit-case-04-10.png)

Link: [https://makecode.microbit.org/_gDhV67AceFJw](https://makecode.microbit.org/_gDhV67AceFJw)

<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:https://makecode.microbit.org/_gDhV67AceFJw" frameborder="0" sandbox="allow-popups allow-forms allow-scripts allow-same-origin">
</iframe>
</div>  


## Result
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- If the device detects any people coming to the farmlands, the red light turns on and the buzzer alarms.