ATCommands

The (in)complete description of ATCommands is documented in Parrot’s AR.Drone Developer Guide chapter 6.5, please refer to it for detailed description of each command.

Using ATCommands

Creating an ATCommand

To create an ATCommand, you have to call the command class with the corresponding arguments.

For example, to create an "AT*PCMD" command with the progressive flag and vertical speed = 0.8:

>>> from pyardrone import at
>>> cmd = at.PCMD(at.PCMD.flag.progressive, 0, 0.8, 0, 0)
>>> cmd
PCMD(flag=<flag.progressive: 1>, roll=0, pitch=0.8, gaz=0, yaw=0)

or using keyword arguments, just like a function:

>>> at.PCMD(at.PCMD.flag.progressive, gaz=0.8)
PCMD(flag=<flag.progressive: 1>, roll=0, pitch=0.8, gaz=0, yaw=0)

ATCommands are collections.namedtuple() subclasses, so reading it is just as easy.

>>> cmd
PCMD(flag=<flag.progressive: 1>, roll=0, pitch=0.8, gaz=0, yaw=0)
>>> cmd.roll
0
>>> cmd.pitch
0.8
>>> cmd[0]
<flag.progressive: 1>
>>> cmd[2]
0.8
>>> list(cmd)
[<flag.progressive: 1>, 0, 0.8, 0, 0]

Additionally _pack() packs the command into bytes

>>> cmd._pack(10)  # pack with sequence number = 10
b'AT*PCMD=10,1,0,1061997773,0,0\r'

Sending an ATCommand

To send a AT*PCMD command with the progressive flag and vertical speed = 0.8, use pyardrone.ARDrone.send()

>>> # drone is an ARDrone instance here
>>> drone.send(at.PCMD(at.PCMD.flag.progressive, 0, 0.8, 0, 0))

send() provides the sequence number for the _pack() function automatically.

Defining ATCommand subclasses

If you want to use an ATCommand not defined in the library, you can define it yourself.

For example, to define a “AT*EXAMPLE” command with three arguments: options, speed, comment, which is a integer, a float, and a string respectively:

from pyardrone.at import base, parameters

class EXAMPLE(base.ATCommand):

    options = parameters.Int32()
    speed = parameters.Float()
    comment = parameters.String(default='nothing')

    options._set_flags(
        eat=0b1,
        sleep=0b10,
        wander=0b100
    )

The created EXAMPLE class can then be used just like other ATCommand classes:

>>> cmd = EXAMPLE(EXAMPLE.options.sleep, 3.5, 'hello')
>>> cmd
EXAMPLE(options=<options.sleep: 2>, speed=3.5, comment='hello')
>>> cmd._pack()
b'AT*EXAMPLE=SEQUNSET,2,1080033280,"hello"\r'
>>> EXAMPLE(options=EXAMPLE.options.wander, speed=6.7)
EXAMPLE(options=<options.wander: 4>, speed=6.7, comment='nothing')

The base ATCommand Class

Subclasses share the following methods:

class pyardrone.at.base.ATCommand(*args, **kwargs)

Base class of all ATCommands

_parameters

A list of Parameters of the command.

_pack(seq='SEQUNSET')

Packs the command into bytes

Parameters:

seq – sequence number

Return type:

bytes

List of ATCommands

class pyardrone.at.REF(input=0, *, use_default_bits=True)

Controls the basic behaviour of the drone (take-off/landing, emergency stop/reset)

class pyardrone.at.PCMD(flag=None, roll=0, pitch=0, gaz=0, yaw=0)

Send progressive commands - makes the drone move (translate/rotate).

flag

flag enabling the use of progressive commands and/or the CombinedYaw mode (bitfield)

Flags:

• progressive = 1

• combined_yaw = 2

• absolute_control = 4

roll

drone left-right tilt, [-1…1]

pitch

drone front-back tilt, [-1…1]

gaz

drone vertical speed, [-1…1]

yaw

drone angular speed, [-1…1]

class pyardrone.at.PCMD_MAG(flag=None, roll=None, pitch=None, gaz=None, yaw=None, psi=None, psi_accuracy=None)

Send progressive commands - makes the drone move (translate/rotate).

flag

flag enabling the use of progressive commands and/or the CombinedYaw mode (bitfield)

roll

drone left-right tilt, [-1…1]

pitch

drone front-back tilt, [-1…1]

gaz

drone vertical speed, [-1…1]

yaw

drone angular speed, [-1…1]

psi

magneto psi, [-1…1]

psi_accuracy

magneto psi accuracy, [-1…1]

class pyardrone.at.FTRIM

Flat trims - Tells the drone it is lying horizontally

class pyardrone.at.CONFIG(key=None, value=None)

Sets an configurable option on the drone

key

the name of the option to set

value

the option value

class pyardrone.at.CONFIG_IDS(session=None, user=None, application_ids=None)

Identifiers for the next AT*CONFIG command

class pyardrone.at.COMWDG

reset communication watchdog

class pyardrone.at.CALIB(device_number=None)

Magnetometer calibration - Tells the drone to calibrate its magnetometer

device_number

Identifier of the device to calibrate - Choose this identifier from ardrone_calibration_device_t.

class pyardrone.at.CTRL(mode=None, zero=0)

Not documented in developer guide, change control mode

mode

Flags:

• NO_CONTROL_MODE = 0

• ARDRONE_UPDATE_CONTROL_MODE = 1

• PIC_UPDATE_CONTROL_MODE = 2

• LOGS_GET_CONTROL_MODE = 3

• CFG_GET_CONTROL_MODE = 4

• ACK_CONTROL_MODE = 5

• CUSTOM_CFG_GET_CONTROL_MODE = 6

Parameters

class pyardrone.at.parameters.Parameter(description='', default=None, name=None, index=None)

Base class of all at command parameters.

Parameters:

• description – description of the parameter, stored in __doc__

• default – default value of the parameter

static _check(value)

Checks the value on ATCommand‘s init. Subclasses can optionally define this method, the default implementation is a no-op.

Raises:

• TypeError – If the value is of the wrong type.

• ValueError – If the value is not valid.

static _pack(value)

Packs the value. Subclasses should define this method.

Return type:

bytes

Parameter types

class pyardrone.at.parameters.Int32(...)

Parameter class of a 32-bit integer.

static _check(value)

Checks the value on ATCommand‘s init. Subclasses can optionally define this method, the default implementation is a no-op.

Raises:

• TypeError – If the value is of the wrong type.

• ValueError – If the value is not valid.

static _pack(value)

Packs the value. Subclasses should define this method.

Return type:

bytes

_set_flags(**flags)

Set the flags of this argument.

Example: int_param._set_flags(a=1, b=2, c=4, d=8)

class pyardrone.at.parameters.Float(...)

Parameter class of a float

class pyardrone.at.parameters.String(...)

Parameter class of a string

static _check(value)

Checks the value on ATCommand‘s init. Subclasses can optionally define this method, the default implementation is a no-op.

Raises:

• TypeError – If the value is of the wrong type.

• ValueError – If the value is not valid.

static _pack(value)

packing rule:

Value	Packes into
True	b'TRUE'
False	b'FALSE'
65535	b'65535'
0.32	b'0.32'
'hello'	b'hello'