Input not working

[quodix]

Good evening everybody.
I have a problem, that my cable bridge (simulates a button) is not regognized by the code.

That is my current code, that is from the Pi4J example:
`import com.pi4j.Pi4J;
import com.pi4j.io.gpio.digital.DigitalInput;
import com.pi4j.io.gpio.digital.DigitalInputProvider;
import com.pi4j.io.gpio.digital.PullResistance;
import com.pi4j.util.Console;

public class TestMain {
/**
* Constant DIGITAL_INPUT_PIN=0
*/
public static final int DIGITAL_INPUT_PIN = 21;

/**
 * <p>Constructor for DigitalInputExample.</p>
 */
public TestMain() {
}

/**
 * <p>main.</p>
 *
 * @param args an array of {@link java.lang.String} objects.
 * @throws java.lang.Exception if any.
 */
public static void main(String[] args) throws Exception {
    // configure logging output
    System.setProperty("org.slf4j.simpleLogger.defaultLogLevel", "INFO");

    // TODO :: REMOVE TEMPORARY PROPERTIES WHEN NATIVE PIGPIO LIB IS READY
    // this temporary property is used to tell
    // PIGPIO which remote Raspberry Pi to connect to
    System.setProperty("pi4j.host", "rpi3bp.savage.lan");

    // create Pi4J console wrapper/helper
    // (This is a utility class to abstract some of the boilerplate stdin/stdout code)
    final var console = new Console();

    // print program title/header
    console.title("<-- The Pi4J Project -->", "Basic Digital Input Example");

    // allow for user to exit program using CTRL-C
    console.promptForExit();

    // Initialize Pi4J with an auto context
    // An auto context includes AUTO-DETECT BINDINGS enabled
    // which will load all detected Pi4J extension libraries
    // (Platforms and Providers) in the class path
    var pi4j = Pi4J.newAutoContext();

    // create a digital input instance using the default digital input provider
    // we will use the PULL_DOWN argument to set the pin pull-down resistance on this GPIO pin
    var config = DigitalInput.newConfigBuilder(pi4j)
            //.id("my-digital-input")
            .address(DIGITAL_INPUT_PIN)
            .pull(PullResistance.PULL_DOWN)
            .build();

    // get a Digital Input I/O provider from the Pi4J context
    DigitalInputProvider digitalInputProvider = pi4j.provider("pigpio-digital-input");

    var input = digitalInputProvider.create(config);

    // setup a digital output listener to listen for any state changes on the digital input
    input.addListener(event -> {
        Integer count = (Integer) event.source().metadata().get("count").value();
        console.println(event + " === " + count);
    });

    // lets read the analog output state
    console.print("THE STARTING DIGITAL INPUT STATE IS [");
    console.println(input.state() + "]");

    console.println("CHANGE INPUT STATES VIA I/O HARDWARE AND CHANGE EVENTS WILL BE PRINTED BELOW:");

    // wait (block) for user to exit program using CTRL-C
    console.waitForExit();

    // shutdown Pi4J
    console.println("ATTEMPTING TO SHUTDOWN/TERMINATE THIS PROGRAM");
    pi4j.shutdown();
}

}`

The Console prints only this:

`[main] INFO com.pi4j.util.Console - ************************************************************
[main] INFO com.pi4j.util.Console - ************************************************************
[main] INFO com.pi4j.util.Console -
[main] INFO com.pi4j.util.Console - <-- The Pi4J Project -->
[main] INFO com.pi4j.util.Console - Basic Digital Input Example
[main] INFO com.pi4j.util.Console -
[main] INFO com.pi4j.util.Console - ************************************************************
[main] INFO com.pi4j.util.Console - ************************************************************
[main] INFO com.pi4j.util.Console -
[main] INFO com.pi4j.util.Console - ------------------------------
[main] INFO com.pi4j.util.Console - | PRESS CTRL-C TO EXIT |
[main] INFO com.pi4j.util.Console - ------------------------------
[main] INFO com.pi4j.util.Console -
[main] INFO com.pi4j.Pi4J - New auto context
[main] INFO com.pi4j.Pi4J - New context builder
[main] INFO com.pi4j.platform.impl.DefaultRuntimePlatforms - adding platform to managed platform map [id=raspberrypi; name=RaspberryPi Platform; priority=5; class=com.pi4j.plugin.raspberrypi.platform.RaspberryPiPlatform]
[main] INFO com.pi4j.util.Console - THE STARTING DIGITAL INPUT STATE IS [
[main] INFO com.pi4j.util.Console - LOW]
[main] INFO com.pi4j.util.Console - CHANGE INPUT STATES VIA I/O HARDWARE AND CHANGE EVENTS WILL BE PRINTED BELOW:

`

Is the digital input pin the same as it is defined (21)? After a long search I found that is a "GPIO" Pin and not the real pin. GPIO-21 = PIN-29? But nothing happen if I short the cable to ground

[FDelporte]

BCM/GPIO 21 is actually pin 40 ...
https://pinout.xyz/pinout/pin40_gpio21/#

And pin 29 is BCM/GPIO 5
https://pinout.xyz/pinout/pin29_gpio5/#

yes, confusing, I know ;-)

you can also check this example that you can run easily with JBang, and the wiring diagram shows you the BCM/GPIO numbering of the Raspberry Pi header
https://pi4j.com/examples/jbang/jbang_minimal_example/

[quodix]

Do I need JBang or can I use the Pi4J library and create my own Project? And is out there any Pin diagram with all BCM infos for the pins?

[FDelporte]

That JBang is only an example! Ofcourse you can use your own project, or Maven, or Gradle, ...

On https://pinout.xyz/pinout you can find all pin info.

[quodix]

One more question.
I want to open Serial port with TX and RX function.
How can I set the RX and TX in the SerialConfig? I only have "Device" to set

[FDelporte]

See https://pi4j.com/documentation/io-examples/serial/

.device("/dev/ttyS0") uses

RX | UART TX, GPIO 15
TX | UART RX, GPIO 16