//////////////////////////////////// // DEVICE-SPECIFIC LED SERVICES // //////////////////////////////////// struct DEV_TempSensor : Service::TemperatureSensor { // A standalone Temperature sensor SpanCharacteristic *temp; // reference to the Current Temperature Characteristic DEV_TempSensor(ServiceType sType=ServiceType::Regular) : Service::TemperatureSensor(sType){ // constructor() method // We begin by defining a new SpanEvent. This instructs HomeSpan to call the Service's event() method (defined below) periodically. // The argument to SpanEvent() defines the periodicity, in milliseconds. In this case we are instructing HomeSpan to check this Service for // updates every 5 seconds. Checking takes time, and updates use network traffic, so choose your periodicity wisely. In practice you could // probably set the periodicity for a temperature sensor to 60 seconds or more. But for illustrative purposes we are specifying more frequent // updates so you can see how the this example works without needing to wait a full minute for each change. new SpanEvent(5000); // check for events on this Service every 5 seconds // Next we instantiate the main Characteristic for a Temperature Sensor, namely the Current Temperature, and set its initial value // to 20 degrees. For a real sensor, we would take a reading and initialize it to that value instead. NOTE: HomeKit uses // Celsius for all temperature settings. HomeKit will DISPLAY temperatures in the HomeKit app according to the settings on your iPhone. // Though the HAP documentation includes a Characteristic that appears to allow the device to over-ride this setting by specifying a display // of Celsius or Fahrenheit for each Service, it does not appear to work as advertised. temp=new Characteristic::CurrentTemperature(20.0); // instantiate the Current Temperature Characteristic Serial.print("Configuring Temperature Sensor"); // initialization message Serial.print("\n"); } // end constructor // Lastly, we create the event() method. This method take no arguments and returns no values. It will be called every 5 seconds // as specified above in the instantiation of SpanEvent(). In order to simulate a temperature change from an actual sensor we // will read the current value of the temp Characteristic using the getVal() function, with as the template parameter; // add 0.5 degrees Celsius; and then store the result in a float variable named "temperature." This will simulate an increment of // 0.5 degrees Celsius (a little less than 1 degree F) every 5 seconds. We will cap the temperature to 35.0 degrees C, after which // it resets to 10.0 and starts over. // All of the action happens in the last line, in which we set the value of the temp Characteristic to the new value of temperature. // This tells HomeKit to send an Event Notification message to all available Controllers making them aware of the new temperature. // Note that setVal() is NOT a template function and does not require you to specify as a template parameter. This is because // setVal() can determine the type from the argument you specify. If there is any chance of ambiguity, you can always specifically // cast the argument such: setVal((float)temperature). void event(){ float temperature=temp->getVal()+0.5; // here we "simulate" a half-degree temperature change... if(temperature>35.0) // ...but cap the maximum at 35 degrees before starting over at 10 degrees temperature=10.0; temp->setVal(temperature); // don't forgot to update the temperature Characteristic to the new value! } // event }; ////////////////////////////////// struct DEV_AirQualitySensor : Service::AirQualitySensor { // A standalone Air Quality sensor // An Air Quality Sensor is similar to a Temperature Sensor except that it supports a wide variety of measurements. // We will use three of them. The first is required, the second two are optional. SpanCharacteristic *airQuality; // reference to the Air Quality Characteristic, which is an integer from 0 to 5 SpanCharacteristic *o3Density; // reference to the Ozone Density Characteristic, which is a float from 0 to 1000 SpanCharacteristic *no2Density; // reference to the Nitrogen Dioxide Characteristic, which is a float from 0 to 1000 DEV_AirQualitySensor(ServiceType sType=ServiceType::Regular) : Service::AirQualitySensor(sType){ // constructor() method new SpanEvent(10000); // check for events on this Service every 10 seconds airQuality=new Characteristic::AirQuality(1); // instantiate the Air Quality Characteristic and set initial value to 1 o3Density=new Characteristic::OzoneDensity(300.0); // instantiate the Ozone Density Characteristic and set initial value to 300.0 no2Density=new Characteristic::NitrogenDioxideDensity(700.0); // instantiate the Nitrogen Dioxide Density Characteristic and set initial value to 700.0 Serial.print("Configuring Air Quality Sensor"); // initialization message Serial.print("\n"); } // end constructor void event(){ airQuality->setVal((airQuality->getVal()+1)%6); // simulate a change in Air Quality by incrementing the current value by one, and keeping in range 0-5 o3Density->setVal((double)random(200,500)); // change the Ozone Density to some random value between 200 and 499. Note use of (double) cast since random returns an integer // Note we are NOT updating the Nitrogen Dioxide Density Characteristic. This should therefore remain steady at its initial value of 700.0 } // event }; ////////////////////////////////// // What you should see in your HomeKit Application // ----------------------------------------------- // If you load the above example, your HomeKit App should display two new tiles: one labeled "Temp Sensor" and the other labeled "Air Quality". // The Temp Sensor tile should indicate a temperature in the range of 10C to 35C (50F to 95F), which automatically increments and updates 0.5C every 5 seconds. // The Air Quality tile should cycle through "quality" states once every 10 seconds. States are displayed in HomeKit as "Unknown", "Excellent", "Good", "Fair", // "Inferior" and "Poor". // Note that HomeKit only displays the values of a subset of Characteristics within the tile itself. In the case of an Air Quality Sensor, // only the quality state of the Air Quality is displayed. To see the values of other Characteristics, such as Ozone Density and Nitrogen Dioxide Density, you need to click // on the tile, AND open the settings screen (it would be nicer if HomeKit displayed these values on the control screen instead of making you open the settings screen). // On the setting screen you should see the values of all three of the Characteristics we instantiated: Air Quality, Nitrogen Dioxide Density, and Ozone Density. // Both the Air Quality and Ozone Density should change every 10 seconds. The Nitrogen Dioxide Density should remain steady at the initial value of 700.0, since we // never use setVal() to update this Characteristic. // If you run HomeSpan at a VERBOSITY level of 2 (as specified in the library's Settings.h file), you can see that under the hood HomeSpan is sending Event Notification // messages to all registered controllers every 5 seconds for the Temp Sensor, and every 10 seconds for the Air Quality Sensor. If you look carefully you'll see that // the Event Notification message for the Air Quality Sensor only include two values - one for the Air Quality state and one for the Ozone Density. HomeSpan is NOT // sending a value for the Nitrogen Dioxide Density Characteristic since it has not been changed with a setVal() function. This is an important design feature and // shows that the instantiation of a new SpanEvent only determines how often the event() method is checked by HomeSpan, not whether Event Notifications are actually sent. // If the event() method ALWAYS updates a Characteristic, then an Event Notification will always be generated. However, if event() does not update a Characteristic, // or only updates it under certain circumstances, then no message will be generated. This allows you to create a SpanEvent that frequenty checks a Service for an // event update, without generating Event Notifications that simply repeat the existing value of a Characteristic. We will see how this comes into play in the next example. // FINAL NOTE: The number of decimals HomeKit displays for temperature in the HomeKit app is independent of the step size of the value itself. This seems to be // hardcoded by HomeKit: for Fahrenheit a Temperature Sensor tile shows no decimals and ROUNDS to the nearest whole degree (e.g. 72, 73, 74 degrees); for Celsius // the tile allows for half-degree resolution and ROUNDS accordingly (e.g. 22.7 is displayed as 22.5 and 22.8 is displayed as 23.0).