mraa/examples/platform/Up2Leds.java

/*
 * Author: Mihai Tudor Panu <mihai.tudor.panu@intel.com>
 * Copyright (c) 2018 Intel Corporation
 *
 * SPDX-License-Identifier: MIT
 */

import mraa.Led;
import mraa.Platform;
import mraa.mraa;

public class Up2Leds {
    static {
        try {
            System.loadLibrary("mraajava");
        } catch (UnsatisfiedLinkError e) {
            System.err.println( "Native code library failed to load."
                + " See the chapter on Dynamic Linking Problems in the SWIG Java documentation for help.\n" + e);
            System.exit(1);
        }
    }

    // Define led names and min/max brightness
    final static String[] ledNames = {"red", "green", "yellow", "blue"};
    final static int minBrightness = 0;
    final static int maxBrightness = 255;

    public static void main(String argv[]) throws InterruptedException {

        // Perform a basic platform and version check
        if (mraa.getPlatformType() != Platform.INTEL_UP2) {
            System.out.println("This example is meant for the UP Squared board.");
            System.out.println("Running it on different platforms will likely require code changes!");
        }

        if (mraa.getVersion().compareTo("v1.9.0") < 0) {
            System.out.println("You need MRAA version 1.9.0 or newer to run this sample!");
            System.exit(1);
        }

        // Define and initialize our LEDs
        Led[] leds = new Led[ledNames.length];
        for (int i = 0; i < ledNames.length; i++) {
            leds[i] = new Led(ledNames[i]);
        }

        // Add a hook for handling keyboard interrupts and cleanup
        Runtime.getRuntime().addShutdownHook(new Thread()
        {
            @Override
            public void run()
            {
                System.out.println("Exiting...");
                for (Led led : leds) {
                    led.setBrightness(minBrightness);
                }
            }
        });

        // Main loop
        while (!Thread.interrupted()) {
            for (Led led : leds) {
                led.setBrightness(maxBrightness);
                Thread.sleep(200);
                led.setBrightness(minBrightness);
            }
            Thread.sleep(200);
        }
    }
}