pololu-maestro

Python driver for the Pololu Maestro series of servo controllers.

Originally cloned from: FRC4564/Maestro

Example Usage

from maestro import Maestro

# Connect to a Micro Maestro
with Maestro.connect('micro') as maestro:
    # Set targets of servos 0-3 to 1500, 1600, 1700, and 1800 us
    maestro.set_target(0, 1500)
    maestro[1] = 1600
    maestro[2:4] = [1700, 1800]

    # Get targets
    assert maestro.get_target(0) == 1500
    assert maestro[1] == 1600
    assert maestro[0:4] == [1500, 1600, 1700, 1800]

# After leaving the block, the Maestro is told to stop sending signals
# to the servos, and the connection is automatically closed

# Connect to a Mini Maestro 12
with Maestro.connect('mini12') as maestro:
    # Servo position may not equal the target
    # if speed or acceleration are set, e.g.:
    # Move servo 10 from 1000 to 2000 us at low speed
    maestro.set_target(10, 1000)
    maestro.set_speed(10, 1)
    maestro.set_target(10, 2000)

    assert maestro.is_moving(10)
    assert maestro.get_position(10) != maestro.get_target(10)
    
    maestro.wait_until_done_moving()
    
    assert not maestro.is_moving(10)
    assert maestro.get_position(10) == maestro.get_target(10)

Methods

The MicroMaestro and MiniMaestro classes have the following methods:

Positioning

• set_target(channel: int, target_us: float): Set the target position of a servo.
• get_target(channel: int) -> float
• set_targets(targets: dict[int, float]): Set the target positions of multiple servos at once.
• get_targets() -> list[float]
• get_position(channel: int) -> float: Get the current position of a servo. May differ from the target if speed or acceleration is non-zero.
• get_positions() -> list[float]
• set_limits(channel: int, min_us: float = None, max_us: float = None)
• get_limits(channel: int) -> tuple[Optional[float], Optional[float]]
• stop_channel(channel: int): Stop sending signals to a servo.
• stop(): Stop all channels.
• go_home(): Set all servos to their home positions.
• is_moving(channel: int) -> bool
• any_are_moving() -> bool
• wait_until_done_moving(poll_period: float = 0.1)

Speed

• set_speed(channel: int, speed: int)
• get_speed(channel: int) -> int
• get_speeds() -> list[int]

Acceleration

• set_acceleration(channel: int, acceleration: int)
• get_acceleration(channel: int) -> int
• get_accelerations() -> list[int]

Analog & Digital I/O

• set_digital(channel: int, value: bool)
• get_digital(channel: int) -> bool
• get_analog(channel: int) -> float
• set_pwm(duty_cycle: float, period_us: float = 340) (Mini Maestro only)

Scripting

• run_script_subroutine(subroutine: int, parameter: int = None)
• script_is_running() -> bool
• stop_script()

Other

• get_errors() -> int

Interactive Mode

The module can be run to interactively control the servo targets:

python -m maestro {micro,mini12,mini18,mini24} [--tty TTY]

Installation & Setup

pip install git+https://github.com/austin-bowen/pololu-maestro.git

Setup System

On Linux, to connect to serial ports without root permissions, you may need to add your user to the dialout group:

sudo usermod -aG dialout $USER

Then log out and back in. Do this step if you get "Permission denied" errors connecting to the Maestro.

Setup Maestro

1. Open the Maestro Control Center (Windows / Linux) and connect it to your Maestro.
2. Go to the Serial Settings tab, and make sure the Serial mode is set to either "USB Dual Port" or "USB Chained".

Local Development

Setup:

python3 -m venv venv
source venv/bin/activate
pip install -e .[test]

Run unit tests and view coverage:

./test