Example from the library Pi4j doesn't work properly

Question

I have created a Java-project using Pi4j and LibGDX. I have integrated the simple example from the official homepage of the Pi4j project in my project. I have changed only the number of the LEDs from 4 to 10 and tested the program with a LED strip (ws2811) with 10 LEDs. Runtime is Java 17 (Liberica JDK). But the first LED doesn't shine. The full code is below:

public class MyGdxGame extends ApplicationAdapter {
        SpriteBatch batch;
        Texture img;
        
        @Override
        public void create () {
            batch = new SpriteBatch();
            img = new Texture("badlogic.jpg");
            System.out.println("LED strip app started ...");
    
            
            int pixels = 10;
            Context pi4j;
            final var piGpio = PiGpio.newNativeInstance();
            pi4j = Pi4J.newContextBuilder()
                    .noAutoDetect()
                    .add(new RaspberryPiPlatform() {
                        @Override
                        protected String[] getProviders() {
                            return new String[]{};
                        }
                    })
                    .add(PiGpioDigitalInputProvider.newInstance(piGpio),
                            PiGpioDigitalOutputProvider.newInstance(piGpio),
                            PiGpioPwmProvider.newInstance(piGpio),
                            PiGpioSerialProvider.newInstance(piGpio),
                            PiGpioSpiProvider.newInstance(piGpio)
                            //LinuxFsI2CProvider.newInstance()
                    )
                    .build();
    
            final LedStrip ledStrip = new LedStrip(pi4j, pixels, 0.5);
    
    //set them all off, so nothing is shining
            System.out.println("Starting with setting all leds off");
            ledStrip.allOff();
    
            System.out.println("setting the LEDs to RED");
            ledStrip.setStripColor(PixelColor.RED);
            ledStrip.render();
            delay(3000);
    
            System.out.println("setting the LEDs to Light Blue");
            ledStrip.setStripColor(PixelColor.LIGHT_BLUE);
            ledStrip.render();
            delay(3000);
    
            System.out.println("setting the first led to Purple");
            ledStrip.setPixelColor(0, PixelColor.PURPLE);
            ledStrip.render();
            delay(3000);
    
            System.out.println("setting the brightness to full and just show the first led as White");
            ledStrip.allOff();
            ledStrip.setBrightness(1);
            ledStrip.setPixelColor(0, PixelColor.WHITE);
            ledStrip.render();
            delay(3000);
    
    //finishing and closing
            ledStrip.close();
            System.out.println("closing the app");
            System.out.println("Color "+ ledStrip.getPixelColor(0));
    
    
            
            System.out.println("LED strip app done.");
        }
    
        @Override
        public void render () {
            ScreenUtils.clear(0, 0, 0, 1);
            batch.begin();
            //batch.draw(img, 0, 0);
            batch.end();
        }
        
        @Override
        public void dispose () {
            batch.dispose();
            img.dispose();
        }
    
        private static void delay(int milliseconds){
            try {
                Thread.sleep(milliseconds);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        }
    }

why doesn't the first LED shine?

Example from the library Pi4j doesn't work properly

0 Answers0