Drexa

Drone control via Alexa. An alexa skill to control a parrot minidrone through voice commands.

See it here in action:

Hardware requirements

• A parrot minidrone like Cargo/Mambo that connects over bluetooth.
• A raspberry pi to bridge AWS to minidrone.

Software requirements

• Configure an alexa skill like DroneControl. See section on alexa skill.
• Configure lambda to bridge alexa voice commands to AWS. See section on lambda.
• Install this kickass library (created by @amymcgovern) on raspberry pi: https://github.com/amymcgovern/pyparrot. This library offers python-api to connect drone over bluetooth.

How does it work

• Skill calls the AWS lambda function, which receives the intent request and sends events to queue (AWS SQS).
• DroneService on Raspberry pi polls SQS and processes event.
• DroneService sends movement instructions to Parrot drone over Bluetooth.

Limitations/Future work

• Queue should have only one consumer and one publisher. It won't work for multiple raspberry-pis polling same queue.
• Add facial recognition in pi to support "ask drone control to come to me" type of usecase.
• Support inter drone communication.

Alexa skill

• This skill supports 6 types of utterances:
  • TakeOffDroneIntent: drone takes off
  • LandDroneIntent: drone lands
  • RotateDroneIntent: drone rotates by +90 or -90 degrees.
    • Slot: RotationType (2 values: [+90, -90])
    • Resolution: "clockwise" -> 90, "counterclockwise" -> -90.
  • DroneMovementIntent: drone moves in 6 possible directions.
    • Slot: DirectionType (6 values: ["up", "down", "left", "right", "forward", "backward"])
  • HoverDroneIntent: drone hovers around one time.
  • FlightPlanIntent: drone calls a hard coded flight plan in flight_plan
• Build model to point various utterances to this intents.
• Set endpoint of this skill as AWS Lambda ARN (that we'll create in next step).

Lamda

• Create a lambda file index.js based on provided index.js.
• The code maps each intent to an actionable handler code. This code extracts slots and creates a JSON payload to be sent to SQS.
  • Lambda also sends out an appropriate voice reply.

SQS

• A simple queue. Since only one drone is in the play, this queue doesn't need any fancy setup to handle ~10 events per minute.

Drone service

Drone service is a inifintely looping program that does the following:

• Polls SQS.
• If a message is available, then extracts payload and calls the corresponding method. For example: "TakeOffDroneIntent" -> takeOff()
• The method calls pyparrot library to execute drone movement like "Move Up", "Move Down", "Land".