# 3.25 Auto-door

## 3.25.1 Overview

Many shopping malls open their doors when someone approaches and close them when no one is detected. Herein, we adopt a PIR motion sensor to simulate this kind of auto-door. The door opens when someone is detected and closes when no one is present.

## 3.25.2 Code Flow

![t168](./media/t168.png)

## 3.25.3 Test Code

You can manually build blocks, or directly open the code file we provide: `3-25-Auto-door.ubp`. If you have any questions about how to open code files or upload code, please back to `1.9 Upload Code`.

**Build code blocks:**

1. In ![](./media/control.png), drag ![](./media/t1.png) and ![](./media/t2.png) to the script area, and stack them together.

![t34](./media/t34.png)

2. When the PIR sensor detects a person, the servo rotates to 180 degrees. It returns to 0° until no one is detected.

![t169](./media/t169.png)

## 3.25.4 Test Result

Connect the coding box to the MicroBlocks via USB or Bluetooth, and click ![t59](./media/t59.png) to upload the code to the coding box. Wave your hand over the PIR motion sensor, and the servo will rotate to 180 degree (door open). After a while, it will back to 0 degree (door close) if nothing is detected.