Alexa.PowerLevelController Interface
The Alexa.PowerLevelController capability interface describes the messages used to control the power level of a device. Use this interface for devices that support power-level control, such as a dimmer switch. For more general properties that can be expressed as a percentage, implement the Alexa.PercentageController interface instead.
For the list of locales that are supported for the PowerLevelController interface, see List of Capability Interfaces and Supported Locales.
Utterances
When you use the Alexa.PowerLevelController interface, the voice interaction model is already built for you. The following examples show some customer utterances:
Alexa, set the power to 40 percent on the fan.
Alexa, increase the power level by 12 on the light switch.
アレクサ、ファンの風量を40パーセントにして。
アレクサ、電気のスイッチでレベルを12にあげて。
After the customer says an utterance, Alexa sends a corresponding directive to your skill.
Properties
The powerLevel property
The Alexa.PowerLevelController interface uses the powerLevel property as the primary property. The property represents the power level of a device expressed as an integer percentage between 0 and 100 inclusive. If the powerLevel property is used to represent a change, then valid values are from -100 to 100 inclusive.
Discovery
You describe endpoints that support Alexa.PowerLevelController using the standard discovery mechanism described in Alexa.Discovery.
Set retrievable to true for all of the interfaces and properties that you report when Alexa sends your skill a state report request. Set proactivelyReported to true for interfaces and properties that you proactively report to Alexa in a change report.
For the full list of display categories, see display categories.
Discover response example
The following example shows a Discover.Response message for an endpoint that supports the Alexa.PowerLevelController and Alexa.ColorController interfaces.
{
"event": {
"header": {
"namespace": "Alexa.Discovery",
"name": "Discover.Response",
"payloadVersion": "3",
"messageId": "<message id>"
},
"payload": {
"endpoints":[
{
"endpointId": "<unique ID of the endpoint>",
"manufacturerName": "<the manufacturer name of the endpoint>",
"modelName": "<the model name of the endpoint>",
"description": "<a description that is shown in the Alexa app>",
"friendlyName": "<device name, displayed in the Alexa app>",
"displayCategories": ["LIGHT"],
"cookie": {},
"capabilities": [
{
"type": "AlexaInterface",
"interface": "Alexa.PowerLevelController",
"version": "3",
"properties": {
"supported": [
{
"name": "powerLevel"
}
],
"proactivelyReported": true,
"retrievable": true
}
},
{
"type": "AlexaInterface",
"interface": "Alexa.ColorController",
"version": "3",
"properties": {
"supported": [
{
"name": "color"
}
],
"proactivelyReported": true,
"retrievable": true
}
}
]
}
]
}
}
}
Directives
SetPowerLevel directive
Support the SetPowerLevel directive so that customers can set the power level on devices.
The following example shows a customer utterance:
Alexa, set the power to 40 percent on the fan.
アレクサ、ファンの風量を40パーセントにして。
SetPowerLevel directive payload details
| Field | Description | Type |
|---|---|---|
powerLevel |
The power level to set the device to. | Integer |
SetPowerLevel directive example
{
"directive": {
"header": {
"namespace": "Alexa.PowerLevelController",
"name": "SetPowerLevel",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>",
"cookie": {}
},
"payload": {
"powerLevel": 40
}
}
}
SetPowerLevel response event
If you handle a SetPowerLevel directive successfully, respond with an Alexa.Response event. In the context object, include the values of all properties that changed. You can respond synchronously or asynchronously. If you respond asynchronously, include a correlation token and a scope with an authorization token.
SetPowerLevel response event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "Response",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.PowerLevelController",
"name": "powerLevel",
"value": 40,
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
SetPowerLevel directive error handling
If you can't handle a SetPowerLevel directive successfully, respond with an Alexa.ErrorResponse event.
AdjustPowerLevel directive
Support the AdjustPowerLevel directive so that customers can adjust the power level on devices.
The following example shows a customer utterance:
Alexa, increase the power level by 12 on the light switch.
アレクサ、電気のスイッチでレベルを12にあげて。
AdjustPowerLevel directive payload details
| Field | Description | Type |
|---|---|---|
powerLevelDelta |
The amount by which to change the power level. | Integer |
AdjustPowerLevel directive example
{
"directive": {
"header": {
"namespace": "Alexa.PowerLevelController",
"name": "AdjustPowerLevel",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>",
"cookie": {}
},
"payload": {
"powerLevelDelta": 12
}
}
}
AdjustPowerLevel response event
If you handle an AdjustPowerLevel directive successfully, respond with an Alexa.Response event. In the context object, include the values of all properties that changed. You can respond synchronously or asynchronously. If you respond asynchronously, include a correlation token and a scope with an authorization token.
AdjustPowerLevel response event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "Response",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.PowerLevelController",
"name": "powerLevel",
"value": 52,
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 500
}
]
}
}
AdjustPowerLevel directive error handling
If you can't handle an AdjustPowerLevel directive successfully, respond with an Alexa.ErrorResponse event.
State reporting
Alexa sends a ReportState directive to request information about the state of an endpoint. When Alexa sends a ReportState directive, you send a StateReport event in response. The response contains the current state of all of the retrievable properties in the context object. You identify your retrievable properties in your discovery response. For more information about state reports, see Understand State Reporting.
StateReport response event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "StateReport",
"messageId": "<message id>",
"correlationToken": "<an opaque correlation token>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>"
},
"payload": {}
},
"context": {
"properties": [
{
"namespace": "Alexa.PowerLevelController",
"name": "powerLevel",
"value": 52,
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 0
}
]
}
}
Change reporting
You send a ChangeReport event to proactively report changes in the state of an endpoint. You identify the properties that you proactively report in your discovery response. For more information about change reports, see Understand State Reporting.
ChangeReport event example
{
"event": {
"header": {
"namespace": "Alexa",
"name": "ChangeReport",
"messageId": "<message id>",
"payloadVersion": "3"
},
"endpoint": {
"scope": {
"type": "BearerToken",
"token": "<an OAuth2 bearer token>"
},
"endpointId": "<endpoint id>"
},
"payload": {
"change": {
"cause": {
"type": "PHYSICAL_INTERACTION"
},
"properties": [
{
"namespace": "Alexa.PowerLevelController",
"name": "powerLevel",
"value": 75,
"timeOfSample": "2017-02-03T16:20:50.52Z",
"uncertaintyInMilliseconds": 0
}
]
}
}
},
"context": {}
}
