Drone Demo

This application connects to and controls a Mavlink drone running PX4 in a simulation environment. Manual scrolling is needed to view drone position on the map(see below).

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Screenshots

A video of the app functionality can be found in the asset folder in the root of the project.

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Features

• This project uses the MVVM architecture paradigm because this is the way.

• Code is contained in one module instead of being separated into modules that represent clean code architecture layers to help stay within time constraints.

• StateFlow is used for reactive programming to observe Drone state in real time.

• Koin is used for Dependency Injection.

• Jetpack Compose is used to declare the UI, because this is part of MAD (Modern Android Design).

• Google Maps are used to display drone location because they already have my info and the the other (good) map apis wanted payment information to gain access even for free tiers.

• Speech Recognition is used to perform vocal commands, Vosk is used to handle this. Vosk performs offline speech recognition and keeps info on device.

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Technologies Used

The following dependencies have been used.

• Jetpack Compose
• Koin (Dependency Injection)
• Mavlink SDK
• Kotlin StateFlow
• Google Maps
• Vosk

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Requirements

Android Studio

The latest version of Android Studio is required. The latest version can be
downloaded from here.

Docker

Docker Desktop

Google Maps API Key

Place your key in the local.properties file like this:

MAPS_API_KEY=<your key>

QGround Control

This is optional if you want to see the drone moving in the simulated environment. The app work will without this. [Download here](Download and Install · QGroundControl User Guide)

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Setup

• After installing Docker

• Ensure host machine and Android device are both on the same wifi network.

• From the terminal of the host machine run:

  docker run --rm -it jonasvautherin/px4-gazebo-headless:1.14.0 <phone ip address>    
  

• While thats running Install the app on the Android device. When both are completed the app should be able to connect to the drone in the simulated environment.

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Usage

To connect to the drone:

• Click the connect drone button twice, give a short pause before the second click.

To fly the drone:

• Use the negative button on the map to zoom all the way out.

• Scroll the map to move directly north, the drone is in Europe.

• When the drone has been located, zoom in close to be able to see its movement.

• Hit the take off button, the drone will be in a hover state.

• Hit the Up button, the drone will ascend about 10 meters. Do this a couple more times(I think the drone can crash into things in the simulator???)

• Once at a decent height that should avoid obstacles such as buildings or trees(or whatever I may have crashed into a few times????) other flight buttons can be explored.

• If the drone is landed in a weird location it might get into a weird state(I think it crashes????) (QGround Control is good to see open fields.)

• Permission needs to be granted for voice commands:

  • take off say - liftoff, takeoff, launch

  • land say - land, touchdown

  • fly up say - move up, fly up

  • fly down say - move down, fly down

  • fly left say - move left, fly left

  • fly right say - move right, fly right

  • fly forward say - move forward, fly forward

  • fly backward say - move backward, fly backward

  • orbit say - orbit, circle

  • stop say - stop, hold, hold position

Notes

• Weird drone states are not handled at this time...

Known Issues

This app has been tested on a OnePlus 9. There may be some unknown defects with other manufactures and or devices.

• If things are left running for a while, the app wont be able to reconnect because the port will still be in use.

• The map needs to be scrolled if the drone moves out of view.

• exception messages are not surfaced to the user yet.

• Some voice commands work better than others due to what gets recognized/accent, etc...

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Improvements

• The MavServer should be ran from a background service, this was omitted for faster development.

• Figure out more MavSDK features to improve connection/disconnection experience. (Not much is documented for the Java language).

• Fix map camera position when drone moves out of view.

• Surface exception messages to user.

• Add a way to save custom voice commands