rainbowhat: add README w/ sample usage

Bug: 33427585

Change-Id: Iaff83690425e3ede7ef5e578f3509625fa9ad98b

README.md

@@ -4,7 +4,7 @@ Android Things user-space drivers
 Sample peripheral drivers for Android Things.
 
 NOTE: these drivers are not production-ready. They are offered as sample
-implementations of Android Things user space drivers for commomn peripherals
+implementations of Android Things user space drivers for common peripherals
 as part of the Developer Preview release. There is no guarantee
 of correctness, completeness or robustness.
 

rainbowhat/README.md

@@ -0,0 +1,182 @@
+Rainbow Hat driver for Android Things
+=====================================
+
+This driver provide easy access to the peripherals available on the [Rainbow Hat for Android Things](https://shop.pimoroni.com/products/rainbow-hat-for-android-things):
+- BMP280 temperature sensor (I2C)
+- HT16K33 segment display (I2C)
+- Capacitive buttons (GPIO)
+- LEDs (GPIO)
+- APA102 RGB LEDs (SPI)
+- Piezo Buzzer (PWM)
+- Servo header (PWM)
+
+
+NOTE: these drivers are not production-ready. They are offered as sample
+implementations of Android Things user space drivers for common peripherals
+as part of the Developer Preview release. There is no guarantee
+of correctness, completeness or robustness.
+
+
+How to use the driver
+---------------------
+
+### Gradle dependency
+
+To use the `rainbowhat` driver, simply add the line
+below to your project's `build.gradle`, where `<version>` matches the last version of the driver available on [jcenter](https://bintray.com/google/androidthings/contrib-driver-rainbowhat/_latestVersion)
+
+```
+dependencies {
+    compile 'com.google.android.things.contrib:driver-rainbowhat:<version>'
+}
+```
+
+### Sample usage
+
+
+```
+// import the RainbowHat driver
+import com.google.android.things.driver.rainbowhat.RainbowHat
+```
+
+```
+// Light up the Red LED.
+Gpio led = RainbowHat.openLed(RainbowHat.LED_RED);
+led.setValue(true);
+// Close the device when done.
+led.close();
+```
+
+```
+// Display a string on the segment display.
+AlphanumericDisplay segment = RainbowHat.openDisplay();
+segment.setBrightness(Ht16k33.HT16K33_BRIGHTNESS_MAX);
+segment.display("ABCD");
+segment.setEnabled(true);
+// Close the device when done.
+segment.close();
+```
+
+```
+// Play a note on the buzzer.
+Speaker buzzer = RainbowHat.openBuzzer();
+buzzer.play(440);
+// Stop the buzzer.
+buzzer.stop();
+// Close the device when done.
+buzzer.close();
+```
+
+```
+// Log the current temperature
+Bmx280 sensor = RainbowHat.openSensor();
+sensor.setTemperatureOversampling(Bmx280.OVERSAMPLING_1X);
+Log.d(TAG, "temperature:" + sensor.readTemperature());
+// Close the device when done.
+sensor.close();
+```
+
+```
+// Display the temperature on the segment display.
+Bmx280 sensor = RainbowHat.openSensor();
+sensor.setTemperatureOversampling(Bmx280.OVERSAMPLING_1X);
+AlphanumericDisplay segment = RainbowHat.openDisplay();
+segment.setBrightness(Ht16k33.HT16K33_BRIGHTNESS_MAX);
+segment.display(sensor.readTemperature());
+segment.setEnabled(true);
+// Close the devices when done.
+sensor.close();
+segment.close();
+```
+
+```
+// Light up the rainbow
+Apa102 ledstrip = RainbowHat.openLedStrip();
+ledstrip.setBrightness(31);
+int[] rainbow = new int[RainbowHat.LEDSTRIP_LENGTH];
+for (int i = 0; i < rainbow.length; i++) {
+    rainbow[i] = Color.HSVToColor(255, new float[]{i * 360.f / rainbow.length, 1.0f, 1.0f});
+}
+ledstrip.write(rainbow);
+// Close the device when done.
+ledstrip.close();
+```
+
+```
+// Detect button press.
+Button button = RainbowHat.openButton(RainbowHat.BUTTON_A);
+button.setOnButtonEventListener(new Button.OnButtonEventListener() {
+    @Override
+    public void onButtonEvent(Button button, boolean pressed) {
+        Log.d(TAG, "button A pressed:" + pressed);
+    }
+});
+// Close the device when done.
+button.close();
+```
+
+```
+// Get native Android 'A' key events when button 'A' is pressed.
+ButtonInputDriver inputDriver = RainbowHat.createButtonInputDriver(RainbowHat.BUTTON_A, KeyEvent.KEYCODE_A);
+inputDriver.register();
+
+// In your Activity.
+@Override
+public boolean onKeyDown(int keyCode, KeyEvent event) {
+    if (keyCode == KeyEvent.KEYCODE_A) {
+        // ...
+    }
+    return super.onKeyDown(keyCode, event);
+}
+@Override
+public boolean onKeyUp(int keyCode, KeyEvent event) {
+    if (keyCode == KeyEvent.KEYCODE_A) {
+        // ...
+    }
+    return super.onKeyUp(keyCode, event);
+}
+```
+
+```
+// Continously report temperature.
+final SensorManager sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
+sensorManager.registerDynamicSensorCallback(new SensorManager.DynamicSensorCallback() {
+    @Override
+    public void onDynamicSensorConnected(Sensor sensor) {
+        if (sensor.getType() == Sensor.TYPE_AMBIENT_TEMPERATURE) {
+            sensorManager.registerListener(
+                    new SensorEventListener() {
+                        @Override
+                        public void onSensorChanged(SensorEvent event) {
+                            Log.i(TAG, "sensor changed: " + event.values[0]);
+                        }
+                        @Override
+                        public void onAccuracyChanged(Sensor sensor, int accuracy) {
+                            Log.i(TAG, "accuracy changed: " + accuracy);
+                        }
+                    },
+                    sensor, SensorManager.SENSOR_DELAY_NORMAL);
+        }
+    }
+});
+```
+
+License
+-------
+
+Copyright 2016 Google Inc.
+
+Licensed to the Apache Software Foundation (ASF) under one or more contributor
+license agreements.  See the NOTICE file distributed with this work for
+additional information regarding copyright ownership.  The ASF licenses this
+file to you 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.