pytello

Python interface for the Tello. This is an alpha version of the software, being released so that we can further develop it and use it in AI class in spring 2020. By the end of the semester, the code will be in beta mode and available for general use.

Documentation

The library is currently all in the Tello class. To create a drone object, import the Tello library and create a Tello object.

from pytello.Tello import Tello

drone = Tello()

Setting up the drone

Communication to the drone is done through sockets. Before any flight, your program will need to tell the drone to listen for commands by calling connect(). At the end of a program, you always want to disconnect. Forgetting to disconnect or the program crashing before the disconnect can leave the socket in an odd state

• connect() - Returns True if it succeeded and False otherwise. It also prints out the result for the user.

• disconnect() - Closes all sockets and prints out results for the user

Flying commands

• takeoff(seconds_to_wait=3) - takeoff and wait the specified number of seconds before returning (to give it time to takeoff)

• land(seconds_to_wait=3) - send the land command and wait the specified number of seconds before returning (to give it time to land)

• sleep(timeout) - sleep for the specified time. drone will hover

• flip(direction, seconds_to_wait=3) - flip in the specified direction, which must be one of left, right, forward, back. sleeps for the specified time before returning to give the drone time to flip

• hover(timeToHover=None) - tells the drone to hover for the specified amount of time

• forward_cm(cm, speed=None) - fly forward the specified number of cm. cm must be in the range [20, 500]. optionally specify a speed in cm/s in the range [10, 100].

• backward_cm(cm, speed=None) - fly backward the specified number of cm. cm must be in the range [20, 500]. optionally specify a speed in cm/s in the range [10, 100].

• left_cm(cm, speed=None) - fly left the specified number of cm. cm must be in the range [20, 500]. optionally specify a speed in cm/s in the range [10, 100].

• right_cm(cm, speed=None) - fly right the specified number of cm. cm must be in the range [20, 500]. optionally specify a speed in cm/s in the range [10, 100].

• up_cm(cm, speed=None) - fly up the specified number of cm. cm must be in the range [20, 500]. optionally specify a speed in cm/s in the range [10, 100].

• down_cm(cm, speed=None) - fly down the specified number of cm. cm must be in the range [20, 500]. optionally specify a speed in cm/s in the range [10, 100].

• move_rectilinear_cm(x, y) - move to the specified x and y coordinates by moving along x first and then y. x and y are both in the range [-500, 500] with negative x meaning backward and positive x meaning forward and negative y meaning left and positive y meaning right.

• fly_at_speed(x, y, z, speed) - fly to x, y, z all in the range [-500, 500] at speed in range [10,100]. Negative x means backward and positive x means forward. Negative y means left and positive y means right. Negative z means down and positive z means up.

• turn_degrees(degrees) - turn degrees in range [-360,360]. Negative means counter-clockwise turns and positive means clockwise turns.

• set_speed(new_speed) - set a new default speed in the range [10, 100]

Sensors

The drone sends sensor information at 10Hz. This is stored in a dictionary called sensors_dict(). The full list of sensors depends if you are in mission pad mode or not and is listed in the SDK from Tello (see sdk_docs). You can also call specific commands to poll the drone.

• check_battery_status() - return the current battery status

• check_current_speed() - returns the current speed of the drone

• check_current_flight_time() - returns the total flight time

• check_wifi_signal() - check the current wifi signal

• check_drone_serial - return the drone serial number

• check_drone_sdk - check the SDK version of the drone

Mission pads

The internal sensors are on by default but the drone does not default to looking for the mission pads. To turn that on, use the following commands.

• turn_on_mission_pads() - this puts the drone into the mode to look for mission pads

• set_mission_pad_direction(forward, downward) - set forward to True to have it look forward for pads as well as downward. Note that the detection rate is faster downward. You can set both as True as well.

• turn_off_mission_pads() - turns off mission pad detection

• get_visible_mission_pad_id() - returns the currently visible mission pad id

• go_to_mission_pad_location(x, y, z, speed, mission_id) - moves the drone to the relative x, y, z location of the mission pad assuming it is visible

Updates

2/4/2020: Alpha release of the code for the AI class