# 3.1 GPIO Web Server

[Longer Vision Robotics](http://www.longervisionrobot.com/en/index.html) provides its own code to test Raspberry Pi 3B's GPIOs. The backend server is written in **Python**, while the frontend interface is written in **javascript**.

Let's check out the source code first:

```
git clone git@github.com:LongerVision/RaspberryPi.git
```

![Image](https://625702022-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LBY-O3EwoOkuXt6PKFT%2F-LBY-TAnIw7CAUhJHWPK%2F-LBY-UDV8tTbgk7q117l%2Fgitclone_lv_gpioserver.jpg?generation=1525300726463945\&alt=media)

To run this code, you will need **python3-rpi.gpio**, run the server from terminal with specified IP address (Raspberry Pi 3B's IP) and an randomly specified unused port number.

![Image](https://625702022-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LBY-O3EwoOkuXt6PKFT%2F-LBY-TAnIw7CAUhJHWPK%2F-LBY-UETSPKWHwSFC2fk%2Fgpioserver.jpg?generation=1525300722638086\&alt=media)

And then, we can interact with the server from a webbrowser by specifying Raspberry Pi 3B's IP with the specified port number, as follows:

![Image](https://625702022-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LBY-O3EwoOkuXt6PKFT%2F-LBY-TAnIw7CAUhJHWPK%2F-LBY-UFJ3icJ02vdszoe%2Frpi3b_gpio_control.jpg?generation=1525300721626624\&alt=media)
