/* * Copyright 2017, The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.androidthings.candle; import android.animation.ObjectAnimator; import android.animation.ValueAnimator; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.animation.BounceInterpolator; import com.google.android.things.pio.PeripheralManager; import com.google.android.things.pio.Pwm; import java.io.IOException; /** * Implement a flickering candle using LEDs connected to PWM * and a simple ObjectAnimator. */ public class HomeActivity extends Activity { private static final String TAG = "EdisonCandle"; // PWM output pin names private static final String YELLOW_PWM = BoardDefaults.getYellowPwmPort(); private static final String ORANGE_PWM = BoardDefaults.getOrangePwmPort(); // Brightness values private static final float BRIGHTNESS_START = 25f; private static final float BRIGHTNESS_END = 100f; // Animation duration private static final int DURATION_MS = 350; // Offset between animations to give the candle more life private static final int DELAY_MS = 150; private Pwm mYellowLed, mOrangeLed; private ObjectAnimator mYellowFlame, mOrangeFlame; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); try { mYellowLed = openLed(YELLOW_PWM); mOrangeLed = openLed(ORANGE_PWM); } catch (IOException e) { Log.w(TAG, "Unable to open LED connections", e); } // Create an run the flicker animations mYellowFlame = animateFlicker(mYellowLed, 0); mOrangeFlame = animateFlicker(mOrangeLed, DELAY_MS); mYellowFlame.start(); mOrangeFlame.start(); } @Override public void onDestroy() { super.onDestroy(); mYellowFlame.cancel(); mOrangeFlame.cancel(); try { closeLed(mYellowLed); closeLed(mOrangeLed); } catch (IOException e) { Log.w(TAG, "Unable to close LED connections", e); } } /** * Open a new LED connection to the provided port name * @throws IOException */ private Pwm openLed(String name) throws IOException { Pwm led = PeripheralManager.getInstance().openPwm(name); led.setPwmFrequencyHz(60.0f); led.setPwmDutyCycle(BRIGHTNESS_START); led.setEnabled(true); return led; } /** * Close the provided PWM connection * @throws IOException */ private void closeLed(Pwm pwm) throws IOException { if (pwm != null) { pwm.setEnabled(false); pwm.close(); } } /** * Create an infinite animation to modify the LED brightness. */ private ObjectAnimator animateFlicker(Pwm led, long delay) { ObjectAnimator animator = ObjectAnimator .ofFloat(led, new BrightnessProperty(), BRIGHTNESS_START, BRIGHTNESS_END) .setDuration(DURATION_MS + delay); // "Bounce" at each end to create a flicker effect animator.setInterpolator(new BounceInterpolator()); // Cycle through the animation forever animator.setRepeatMode(ValueAnimator.REVERSE); animator.setRepeatCount(ValueAnimator.INFINITE); return animator; } }