tello-drone

Disclaimer:

Im a student learning how to work and publish packages on NPM. This is a simple package that allows you to communicate with a DJI Tello drone in a much easier way. Any feedback / help / improvement is appreaciated and i will hopefully be able to look into fixing bugs and such when i can.

This project is currently a work in progress, but as of 1.0.1 it can communicate with a tello drone with the sample code bellow.

Information

You can communicate with the drone synchronous or asynchronous. You can pass an option object to switch to asynchronous (synchronous by default). When you connect to the drone it automatically sends the 'command' command, so that is not nececary. If you are working with the drone synchronous, you need to wait for the OK message from the drone before you can send the next command.

Error handling

The drone gives very minimal feedback on errors. Command verification is already built in, it will throw an error if a command is invalid. If you recieve back an error and the drone does not execute the command, the most common reason in my experience is low battery. Charging the battery and trying again solves that error issue.

Methods and options

const tello = require("tello-drone");

// All option parameters are optional, default values shown
const drone = tello.connect(
    {
      async: false,             // makes the send method async.
      host: "192.168.10.1",     // manually set the host.
      port: "8889",             // manually set the port.
      statePort: "8890",        // manually set the state port.
      skipOK: false,            // dont send the OK message.
      bufferOffset: 0           // buffer offset for dgram.
    }
);

// Sends a command to the drone
drone.send("battery?")

// Sends a command to the drone without verifying the command
drone.forceSend("battery?")

// Attaches a callback to a specific event
drone.on(event, callback)

/** All events of the on method
 * connection   - Fired when connected to the drone.             callback()
 * state        - Fired when the drone sends its state message.  callback(stateObject, udpConnection)
 * send         - Fired when a command is sent.                  callback(error, messageLength)
 * message      - Fired when the drone sends a status message.   callback(message, udpConnection)
 */


tello.DELAYS // All the rough delays for each command when in synchronous mode

Asynchronous example

const tello = require("tello-drone");

const drone = tello.connect({ async: true });

drone.on("connection", () => {
    console.log("Connected to drone");
});

drone.on("state", state => {
    console.log("Recieved State > ", state);
});

drone.on("send", (err, length) => {
    if (err) console.log(err);

    console.log(`Sent command is ${length} long`);
});

drone.on("message", message => {
    console.log("Recieved Message > ", message);
});

drone.on("connection", async () => {
    try {
        await drone.send("takeoff");
        await drone.send("flip", { value: "f" });
        await drone.send("land");
    } catch (error) {
        console.log(error)
        drone.send("land")
        //A short delay so that the land command can be sent before exiting
        setTimeout(process.exit)
    }
});

Video demo

Synchronous example

const tello = require("tello-drone");

const drone = tello.connect();

drone.on("connection", () => {
    console.log("Connected to drone");
});

drone.on("state", state => {
    console.log("Recieved State > ", state);
});

drone.on("send", (err, length) => {
    if (err) console.log(err);

    console.log(`Sent command is ${length} long`);
});

drone.on("message", message => {
    console.log("Recieved Message > ", message);
});

drone.send("battery?");

Avaliable commands to send

Tellos official SDK documentation with all commands:

Check your firmware version for the right manual (most likely 1.3)

1.0: https://dl-cdn.ryzerobotics.com/downloads/tello/0228/Tello+SDK+Readme.pdf

1.3: https://dl-cdn.ryzerobotics.com/downloads/tello/20180910/Tello%20SDK%20Documentation%20EN_1.3.pdf

2.0: https://dl-cdn.ryzerobotics.com/downloads/Tello/Tello%20SDK%202.0%20User%20Guide.pdf

Here are the most used ones: command, takeoff, land, up, down, left, right, forward, back, flip, speed, speed?, battery?

Buttars/tello-drone