1. README
2. Interfaces
3. Echo Button and Gadget Skills

Echo Button and Gadget Skills

• GadgetController Interface
  • Set Light
  • Animations
    • Sequence
• Game Engine Interface
  • Recognizers
  • Pattern Recognizer
  • Pattern Object
  • Deviation Recognizer
  • Progress Recognizer
  • Events
  • StartInputHandler
  • StopInputHandler
  • Input Handler Events

GadgetController Interface

With the GadgetController interface you can create animations for the light bulb in the Echo Button.

But first you have to enable the GadgetController interface either in your project.js file, if you're working with the Jovo CLI, or in the Alexa Developer Console in the Interfaces tab.

To do it with the Jovo CLI simply add the interface to the alexaSkill object in your project.js:

Don't forget to build and deploy your project after you've added the interface:

Set Light

To change the light of the user's Echo Buttons you have to use the GadgetController.SetLight directive

Animations

The animations object contains the animation steps in chronological order as well as the number of repetitions.

Sequence

A sequence is simply an array of steps, which can each have a different color, duration, etc.. Every sequence can only have a set amount of steps, which depends on the number of gadgets that sequence has to be applied to. Amazon provides a formula to calculate the number of steps allowed: maxStepsPerSequence = 38 - numberOfTargetGadgetsSpecified * 3.

You can also have a zero-step animation that will clear the current animation set for the trigger.

A sequence has the following parameter:

Game Engine Interface

The Alexa GameEngine interface provides the toolset to receive Echo Button events using the Input Handler.

To get a better understanding how the GameEngine interface works you should go for a bottom up approach since everything is built in top of each other. Therefore we will start with the Recognizers first proceed with the Events, go over the Start- and StopInputHandler directive and finish with the InputHandlerEvents.

But first you have to enable the GameEngine interface either in your project.js file, if you're working with the Jovo CLI, or on the Alexa Developer Console in the Interfaces tab.

To do it with the Jovo CLI simply add the interface to the alexaSkill object in your project.js:

Don't forget to build and deploy your project after you've added the interface:

Recognizers

The primary use case of recognizers is to track Echo Button inputs to look for patterns, which were defined at the creation of the respective recognizer. These are called PatternRecognizer.

There are also two varations, which can either track the progress of another recognizer or check if the user has deviated from an expected pattern, called ProgressRecognizer and DeviationRecognizer respectively.

Recognizers are either true or false at any point of time. Examples:

• The user has not reached the defined progress of your ProgressRecognizer, which means the recognizer is currently false.
• The user has deviated from the pattern you specified in the DeviationRecognizer, which means the recognizer is currently true.

Pattern Recognizer

As described earlier, the PatternRecognizer tracks the raw Echo Button events to look for the specified pattern.

Pattern Object

A pattern object has three values, namely gadgetIds, colors and action. None of the values are required, but if they are left out, they will be handled as wildcards, i.e. everything works.

Code Example for Pattern Recognizer

To create a PatternRecognizer you need the PatternRecognizerBuilder:

With the builder you can use the methods described above:

Deviation Recognizer

The deviation recognizer is used to check if the player has deviated from an expected pattern defined in one of your pattern recognizers.

Code Example for Deviation Recognizer

To create a DeviationRecognizer you need the DeviationRecognizerBuilder:

With the builder you can use the method described above:

Progress Recognizer

The progress recognizer is used to monitor how close the user is to completing the pattern of one of your pattern recognizers.

Code Example for Progress Recognizer

To create a ProgressRecognizer you need the ProgressRecognizerBuilder:

With the builder you can use the methods described above:

Events

Events are used to define the conditions under which your skill will be notified of Echo Button input. You define these conditions using the recognizers we discussed above.

Code Example for Events

To create an Event you need the EventBuilder:

With the builder you can use the methods described above:

StartInputHandler

The StartInputHandler directive is the starting point at which you define the conditions under which your skill will receive the Echo Button events. At any point of time there can only be a single Input Handler active.

The directive has the following four parameters, which are all required besides proxies:

StopInputHandler

You can at any point in time stop receiving Echo Button events using by stopping the Input Handler:

Input Handler Events

After you started the Input Handler your skill will be able to receive InputHandlerEvents. These are the events you specified beforehand and are received just like any other request.

Jovo maps these requests to the built-in ON_GAME_ENGINE_INPUT_HANDLER_EVENT intent, where you can access the events sent with the request:

Responding to Input Handler Events

Responding to GameEngine requests is optional. If you do respond Alexa handles the respond the usual way with slight differences:

• Card will only be displayed on Echo devices with a screen, not the app.
• Responses to GameEngine requests can't end the skill session, which means the shouldEndSession parameter in your response will be ignored
• An error in your response won't end the session but rather trigger a System.ExceptionEncountered error request.