Raspberry Pi 2 Mod B - GPIO How

HarrySatt

Hi

I am usind a Raspberry Pi 2 Mod B with NetBeans 8.1, Oracle JDK ME 8.2. I have established all connections and the sample program GPIOSample is compiling and running on th RPi but none of the pins is working. After that I removed all extra stuff and only use the code for setting the output pin 7. Added some code to set and reset the pins value. That also compiles but I don't see any pin working. From my point of view it should be RPi GPIO socket number 26. what am I douing wrong?

Regards, harald

Code should go into GPIOSample

/*

* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

*/

package com.oracle.jmee.samples.gpio;

import java.io.IOException;

import javax.microedition.midlet.MIDlet;

import jdk.dio.DeviceManager;

import jdk.dio.gpio.GPIOPin;

/**

* GPIOSample demonstrates basic GPIO functionality. The sample opens the

* following DIO devices:

*/

public class GPIOSample extends MIDlet {

    // GPIO pin which corresponds to a LED

    private GPIOPin led = null;

    @Override

    public void startApp() {

        System.out.println("******************************************");

        System.out.println("*         GPIO Sample started!           *");

        System.out.println("******************************************");

        try {

            int ledPinId = 7;

            System.out.println("Opening the GPIO pin with id " + ledPinId + " for the LED");

            led = DeviceManager.open(ledPinId);

            System.out.println("Success opening GPIO pin id " + ledPinId + " for the LED");

        } catch (IOException ex) {

            System.out.println("Cannot open pin");

            destroyApp(true);

        }

       

        boolean val = true;

        for( int i=0; i<20; i++)

        {

            try {

                Thread.sleep(500); // I know. Should not be done. Only for testing

            }

            catch( InterruptedException ex)

            {

                System.out.println("  !!! Interrupted exception");

            }

            try {

                val = !led.getValue();

                led.setValue(val);

            }

            catch ( IOException ex) {

                System.out.println(" caught IOException ex");

            }

            System.out.println(" ***  next state change: " + i + " is " + val);

        }

        destroyApp(true);

    }

    @Override

    public void destroyApp(boolean unconditional) {

        System.out.println("******************************************");

        System.out.println("*         GPIO Sample destroyed          *");

        System.out.println("******************************************");

        notifyDestroyed();

    }

}

Adam G

Did you set the api permission?

I just got my LED project working this afternoon, I had trouble with the code. You can try this to see if yours works. Sound like we have the same setup.

Some quick notes. it seem you need to define the pin everytime by:

  GPIOPinConfig config1 = new GPIOPinConfig(0,22, GPIOPinConfig.DIR_OUTPUT_ONLY,DeviceConfig.UNASSIGNED, 0, false);

Then call the pin

GPIOPin PIN1 = DeviceManager.open(config1);

and for a quick to test was to turn the pin off then on.

PIN1.setValue(true);

            Thread.sleep(4000);

            PIN1.close();

II used GPIO pin 22 which is actual pin 15 on the board.

if you need more let me know, would be happy to help.

I can send you my whole script if you like

Adam

Adam G

Did you set the api permission?

I just got my LED project working this afternoon, I had trouble with the code. You can try this to see if yours works. Sound like we have the same setup.

Some quick notes. it seem you need to define the pin everytime by:

  GPIOPinConfig config1 = new GPIOPinConfig(0,22, GPIOPinConfig.DIR_OUTPUT_ONLY,DeviceConfig.UNASSIGNED, 0, false);

Then call the pin

GPIOPin PIN1 = DeviceManager.open(config1);

and for a quick to test was to turn the pin off then on.

PIN1.setValue(true);

            Thread.sleep(4000);

            PIN1.close();

II used GPIO pin 22 which is actual pin 15 on the board.

if you need more let me know, would be happy to help.

I can send you my whole script if you like

Adam

Adam G

Harry,  I changed your code a bit here:

It did work on the rpi.  also removed a small piece for testing purpose. and right now you need to kill the process manually, but it did light up the led and with this code.

Sorry I'm not a java guy at all, Im learning as I go,

package oracle;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.microedition.midlet.MIDlet;
import jdk.dio.DeviceConfig;
import jdk.dio.DeviceManager;
import jdk.dio.gpio.GPIOPin;
import jdk.dio.gpio.GPIOPinConfig;

/**

* GPIOSample demonstrates basic GPIO functionality. The sample opens the

* following DIO devices:

*/

public class Oracle extends MIDlet {
    // GPIO pin which corresponds to a LED
    private GPIOPin led = null ;

    @Override
    public void startApp() {

        System.out.println("******************************************");
        System.out.println("*         GPIO Sample started!           *");
        System.out.println("******************************************");

        try {
            GPIOPinConfig config1 = new GPIOPinConfig(0,22, GPIOPinConfig.DIR_OUTPUT_ONLY,DeviceConfig.UNASSIGNED, 0, false);
           int ledPinId = 22;

            System.out.println("Opening the GPIO pin with id " + ledPinId + " for the LED");

            GPIOPin PIN22 = DeviceManager.open(config1);
            PIN22.setValue(true);
            Thread.sleep(4000);
            PIN22.close();

            System.out.println("Success opening GPIO pin id " + ledPinId + " for the LED");

        } catch (IOException ex) {

            System.out.println("Cannot open pin");

            destroyApp(true);

        } catch (InterruptedException ex) {
            Logger.getLogger(Oracle.class.getName()).log(Level.SEVERE, null, ex);
        }

       

    }

    @Override

    public void destroyApp(boolean unconditional) {

        System.out.println("******************************************");

        System.out.println("*         GPIO Sample destroyed          *");

        System.out.println("******************************************");

        notifyDestroyed();

    }

}

HarrySatt

Hi Adam

That solution works with Pin 7 (GPIO7) as well as Pin 15 (GPIO22). I wonder why there is a difference to all the samples I read and tried out. the original samples do not word altough I tried the Raspberry 8 (Revision 000d). Thanks a lot.

Harald.

HarrySatt

Hi Adam

I found out some issues with might be helpful for you. You can use the following document

https://docs.oracle.com/javame/8.2/get-started-rpi/piportsapdx.htm

2

GPIO7

GPIO 7

controllerNumber = 0 pinNumber = 7 direction = GPIOPinConfig.DIR_OUTPUT_ONLY mode = GPIOPinConfig.MODE_OUTPUT_PUSH_PULL trigger = GPIOPinConfig.TRIGGER_BOTH_EDGES initValue = false

which gives you information about devices, so you do not need to set the pns with GPIOPinConfig. But there is an error in the doc. Do not relate to the pinNumber in the listing use the pin as shown in the drawing underneath the list. there you have your GPIO<num> and the correct pin number. It differs from the list.

with this information you can open device 2 f.e. and measure voltage changes on pin 26 of P8 on the RPi without using GPIOPinConfig.

Regards, harald.

following an example:

/*

* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

*/

package com.oracle.jmee.samples.gpio;

import java.io.IOException;

import javax.microedition.midlet.MIDlet;

import jdk.dio.DeviceManager;

import jdk.dio.gpio.GPIOPin;

import jdk.dio.gpio.GPIOPinConfig;

/**

* GPIOSample demonstrates basic GPIO functionality. The sample opens the

* following DIO devices:

*/

public class GPIOSample extends MIDlet {

    // GPIO pin which corresponds to a LED

    private GPIOPin led = null;

    @Override

    public void startApp() {

        System.out.println("******************************************");

        System.out.println("*         GPIO Sample started!           *");

        System.out.println("******************************************");

        try {

            int ledDeviceID = 2; // in sample RPi pin 26 is used. work with RPi B and RPi2b

            System.out.println("Opening the GPIO pin with id " + ledDeviceID + " for the LED");

            led = DeviceManager.open(ledDeviceID);

            System.out.println("Success opening GPIO pin id " + ledDeviceID + " for the LED");

        } catch (IOException ex) {

            System.out.println("Cannot open pin");

            destroyApp(true);

        }

       

        boolean val = true;

        for( int i=0; i<20; i++)

        {

            try {

                Thread.sleep(1000); // I know. Should not be done. Only for testing

            }

            catch( InterruptedException ex)

            {

                System.out.println("  !!! Interrupted exception");

            }

            try {

                val = !led.getValue();

                led.setValue(val);

            }

            catch ( IOException ex) {

                System.out.println(" caught IOException ex");

            }

            System.out.println(" ***  next state change: " + i + " is " + val);

        }

        destroyApp(true);

    }

    @Override

    public void destroyApp(boolean unconditional) {

        System.out.println("******************************************");

        System.out.println("*         GPIO Sample destroyed          *");

        System.out.println("******************************************");

        notifyDestroyed();

    }

}