How to create an Android App using Google’s App Inventor

Wed, 04 Aug 2010 00:00:00 +0200

Today we’re going to take a look at Google’s App Inventor feature that offers programming-novices a nice possibility to enter the fabulous world of Android App programming without deeper knowledge of the API or complex SDK installations.

So lets build some stuff ..

Prerequisites

Java 6 JDK
App Inventors Extras Software
A Google App Inventor Beta Account – request one here

What we are going to build

We are building a simple GUI with a Textbox and a button
A click on the button starts an event that queries the acceleration sensor for coordinates
If the sensor is active and enabled then the coordinates are displayed in the text box

Sensor Fun: Using the accelerometer on Android

Tue, 27 Apr 2010 00:00:00 +0200

Here is an example on how to use the accelerometer in your Android application. If you want to simulate the acceleration on the emulator I highly recommend the Sensor Simulator on the OpenIntents website.

The following example app displays the coordinates received by the sensor.

The Acceleration App

The activity – AccelerationActivity.java

package com.hascode.android;

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.TextView;

public class AccellerationActivity extends Activity {
	private TextView result;
	private SensorManager sensorManager;
	private Sensor sensor;
	private float x, y, z;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
		sensor = sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);

		result = (TextView) findViewById(R.id.result);
		result.setText("No result yet");
	}

	private void refreshDisplay() {
		String output = String
				.format("x is: %f / y is: %f / z is: %f", x, y, z);
		result.setText(output);
	}

	@Override
	protected void onResume() {
		super.onResume();
		sensorManager.registerListener(accelerationListener, sensor,
				SensorManager.SENSOR_DELAY_GAME);
	}

	@Override
	protected void onStop() {
		sensorManager.unregisterListener(accelerationListener);
		super.onStop();
	}

	private SensorEventListener accelerationListener = new SensorEventListener() {
		@Override
		public void onAccuracyChanged(Sensor sensor, int acc) {
		}

		@Override
		public void onSensorChanged(SensorEvent event) {
			x = event.values[0];
			y = event.values[1];
			z = event.values[2];
			refreshDisplay();
		}

	};
}

Accelerometer on Micha Kops' Tech Notes

How to create an Android App using Google’s App Inventor

Prerequisites

What we are going to build

Sensor Fun: Using the accelerometer on Android

The Acceleration App