Skip to content

Latest commit

 

History

History
119 lines (92 loc) · 3.18 KB

courseNotes.md

File metadata and controls

119 lines (92 loc) · 3.18 KB
Raw

Raspberry Pi Crash Course using Java

Welcome everyone!

Today I will be walking through how to host a Spring Boot server on a Raspberry Pi to control an LED using an web UI.

You can find a link to my first LED test project here: https://github.com/ArcSoftware/PiLedTest

Fork and Clone this Repo.

First we will fork this repository. Then we will clone the new repo by the following git command:

/git clone [your new repo URL.git]
Note: Your current directory is where the cloned project will be placed.

If you don't have Git on your computer already, you can do this by the following:

Linux:

$ sudo yum install git-all

MacOSX:

Install HomeBrew, then Git:

Homebrew:

$ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Git:

$ brew install git

Windows:

Install here: http://msysgit.github.io

Now that we have the repo locally, open the project in IntelliJ.

Open new project with all default settings, adding only "Auto-Import".

Create a Java Class named "PiCourseController".

Copy the following code into your controller class:

@Controller
public class PiCourseController {
    private RaspberryPiManager piManager;

    public PiCourseController() {
        piManager = new RaspberryPiManager();

    @RequestMapping(path = "/", method = RequestMethod.GET)
    public String home(Model model, String led) {
        if (led != null) { piManager.toggleLED(led);}
        return "index";
    }
}

Now create a Java Class named "PiManager".

Copy the following code into your new manager class:

public class PiManager {
    private final GpioController gpio;
    private GpioPinDigitalOutput testLED;

    public PiManager() {
        gpio = GpioFactory.getInstance();
        testLED = gpio.provisionDigitalOutputPin(RaspiPin.GPIO_04, "testLED", PinState.LOW);
    }

    public void toggleLED(String led) {
        if (led.equalsIgnoreCase("testled")) {
            testLED.toggle();
    }
}

Finally we need to create the HTML interface to call the new fuction we have created.

Open the HTML file named "index.html" that I have pre created for you and paste the following code into the body:

Toggle Light: <a href="/?led=testled"><button>LED</button></a>

Now build your Gradle project from the Gradle menu.

That's it for the code! Now lets push our code, and spin up a web server!

Perform the following to get your code updated on your GitHub account:

$ git add .
$ git commit -m "adding changes"
$ git push

Now SSH into your Pi using terminal: (PuTTY for Windows)

$ ssh [email protected].[subnet].[ip]
password: raspberry

Perform the following once connected:

$ sudo apt-get install git
$ curl -s get.pi4j.com | sudo bash

Change to a good directory to clone your repo as you did before:

$ git clone [repo.git]

Change to the jar directory:

cd PiCourse\builds\libs
ls

Start your spring server!

sudo java -jar [jar file name]

Now we go to the URL of your Pi and the port of Spring Boot:

192.168.[subnet].[ip]:8080