/TelloDroneJavaConnect

Primary LanguageJava

TelloDroneJavaConnect

⚠️ queue system is not fully tested yet!

At the moment the queue is working but things like

August 2019: Added support for front camera on drone

You must have FFMPEG installed on your computer and added it your path test your installation with this command in the terminal: "ffmpeg -version"

images are saved as jpg-files in a folder named grabbedImages

**September 2019: minor changes Queue is working

A brief example of how to program a Tello drone with Java. Tello drones accept commands through UDP and responds with a short text message

You can find further information about the drone here: [https://www.ryzerobotics.com/tello/downloads] including the full SDK describing all commands accepted by the drone

Code Example

This example makes it very easy to commmunicate with the drone - see the code below:

    // Create Drone instance
    TelloDrone drone = new TelloDrone();

    // write commands to console
    drone.setLogToConsole(true);

    // Sending commands to drone
    drone.connect();

    drone.streamOn();

    drone.takeoff();
    drone.rotateClockwise(360);
    drone.land();

Look in the documentation for more commands

Using the command queue

You can add a queue of commands you want executed in a separate thread. This might be handy if you need to fly the drone to a specific place while you do something else in your program

    // create a queue of commands and execute them

    drone.addToCommandQueue("sdk?");
    drone.addToCommandQueue("sn?");
    drone.addToCommandQueue("takeoff");
    drone.addToCommandQueue("ccw 180");
    drone.addToCommandQueue("cw 180");
    drone.addToCommandQueue("land");


    //disable logging drone and use the eventlistener below instead
    drone.setLogToConsole(false);

    // add eventlistener to the "drone command queue"
    drone.addCommandQueueEventListener(new TelloDrone.DroneCommandEventListener() {
        @Override
        public void commandExecuted(TelloDrone.Command command)
        {
            System.out.println("Command Executed:");
            System.out.println(command);

        }

        @Override
        public void commandFinished(TelloDrone.Command command)
        {
            System.out.println("Command Finished:");
            System.out.println(command);
        }

        @Override
        public void commandAdded(TelloDrone.Command command)
        {
            System.out.println(command.getCommand() + " added to queue");

        }

        @Override
        public void commandQueueFinished() {
            System.out.println("Done. No more commands in queue");
        }
    });

    drone.startCommandQueue();

How to run this project

This project has no other requirements than an actual Tello Drone. Just folow these steps and you should be up and running in a matter of minutes

  • Download this project and open it in intelliJ or another java IDE
  • Turn on the Tello drone
  • Connect your computer to the Tello Wifi
  • Run the code....

getting video stream from the Tello drone

You can grab the stream if you have ffmpeg installed and has send the 'streamon' command to the drone

ffplay -probesize 32 -i udp://@:11111 -framerate 30

Documentation

public class TelloDrone

  • Author: Ebbe Vang

  • Version: 0.1

    This class connects to a Tello drone using a UDP connection and sends commands to the drone

    Supports all commands in sdk1.

public boolean connect()

connects to the drone using the 'command' comamnd and allows you to send further commands

  • Returns: whether the drone is connected or not

private boolean sendMessage(String command)

Send any command to the drone - see the sdk for more details about the commands you can send to the drone

  • Parameters: command — the command you want to send to the drone
  • Returns: whether the command is accepted or not

public boolean takeoff()

The drone takes off - The drone will rise about 1 meter

  • Returns: whether the command is accepted or not

public boolean land()

The drone lands

  • Returns: whether the command is accepted or not

public boolean goDown(int cm)

move drone down

  • Parameters: cm — distance in cm
  • Returns: whether the command is accepted or not

public boolean goUp(int cm)

move drone up

  • Parameters: cm — distance in cm
  • Returns: whether the command is accepted or not

public boolean goLeft(int cm)

move drone left

  • Parameters: cm — distance in cm
  • Returns: whether the command is accepted or not

public boolean goRight(int cm)

move drone right

  • Parameters: cm — distance in cm
  • Returns: whether the command is accepted or not

public boolean goForward(int cm)

move drone forward

  • Parameters: cm — distance in cm
  • Returns: whether the command is accepted or not

public boolean goBackwards(int cm)

move drone backwards

  • Parameters: cm — distance in cm
  • Returns: whether the command is accepted or not

public boolean streamOn()

start video stream from front camera

  • Returns: whether the command is accepted or not

public boolean streamOff()

Stop streaming from front camera

  • Returns:

public boolean rotateClockwise(int degrees)

The Drone will turn clockwise

  • Parameters: degrees — you want the drone to turn - must be between 0 and 360
  • Returns: whether the command is accepted or not

public boolean rotateCounterClockwise(int degrees)

The Drone will turn counter clockwise

  • Parameters: degrees — you want the drone to turn - must be between 0 and 360
  • Returns: whether the command is accepted or not

public boolean isLogToConsole()

Log status.

  • Returns: If the drone is writing to the console or not

public boolean emergency()

Stops motors immediately!*

  • Returns:

public void setLogToConsole(boolean logToConsole)

activate or deactivate log to console

  • Parameters: logToConsole — Log to console

public int grabImage()

grab image from front camera. image will be saved in grabbedImages folder

  • Returns: image number - which is used as a filename

public String getGrabbedImageURL()

get URL for latest image taken by grabbedImage method

  • Returns: image url as string

public boolean setSpeed(int speed)

Set drone speed

  • Parameters: speed — in cm/s (1-100)
  • Returns: whether the speed is set or not

public double getSpeed()

g get the speed of the drone i cm/s

  • Returns: speed in cm/s (1-100)

public int getBatteryPercentage()

get the battery charge level in percentage

  • Returns: battery charge in percentage (1-100)

public String getTime()

get time droen has been in the air

  • Returns: time flying

public void addToCommandQueue(String command)

Add to queue of commands

  • Parameters: command —

public void startCommandQueue()

start executing commands from command queue in separate thread

public void suspendCommandQueue()

suspend command queue

public void resumeCommandQueue()

resume command queue

public void addCommandQueueEventListener(DroneCommandEventListener listener)

add eventlistener to command queue

  • Parameters: listener —

public void removeCommandQueueEventListener(DroneCommandEventListener listener)

remove eventlistener from command queue

  • Parameters: listener —

public void clearCommandQueue()

remove all commands from queue