pyax12 0.4.dev6

A library to control dynamixel AX-12+ servos with python

PyAX-12

Copyright (c) 2010,2015 Jeremie DECOCK (http://www.jdhp.org)

• Web site: http://www.jdhp.org/projects_en.html#pyax12

• Online documentation: http://pyax-12.readthedocs.org

• Source code: https://github.com/jeremiedecock/pyax12

• Issue tracker: https://github.com/jeremiedecock/pyax12/issues

• PyAX-12 on PyPI: https://pypi.python.org/pypi/pyax12

In collaboration with http://www.vorobotics.com

Description

PyAX-12 is an open source lightweight Python library to control Dynamixel AX-12+ actuators.

Note:

This project is still in beta stage, so the API is not finalized yet.

Dependencies

• Python >= 3.0

• Python-serial

PyAX-12 is tested to work with Python 3.4 under Gnu/Linux Debian 8 and Windows 7. It should also work with Python 3.X under recent Gnu/Linux and Windows systems. It hasn’t been tested (yet) on MacOSX and BSD systems.

Python-serial is required to install PyAX-12.

Note:

If you use pip to install PyAX-12, Python-serial will be automatically downloaded and installed (see the following install section).

Installation

Gnu/Linux

You can install, upgrade, uninstall PyAX-12 with these commands (in a terminal):

pip install --pre pyax12
pip install --upgrade pyax12
pip uninstall pyax12

Or, if you have downloaded the PyAX-12 source code:

python3 setup.py install

Windows

Note:

The following installation procedure has been tested to work with Python 3.4 under Windows 7. It should also work with recent Windows systems.

You can install, upgrade, uninstall PyAX-12 with these commands (in a command prompt):

py -m pip install --pre pyax12
py -m pip install --upgrade pyax12
py -m pip uninstall pyax12

Or, if you have downloaded the PyAX-12 source code:

py setup.py install

MacOSX

Note:

The following installation procedure has been tested to work with Python 3.4 under MacOSX 10.6 (Snow Leopard). It should also work with recent MacOSX systems.

You can install, upgrade, uninstall PyAX-12 with these commands (in a terminal):

pip install --pre pyax12
pip install --upgrade pyax12
pip uninstall pyax12

Or, if you have downloaded the PyAX-12 source code:

python3 setup.py install

Documentation

• Online Documentation: http://pyax-12.readthedocs.org

• API Documentation: http://pyax-12.readthedocs.org/en/latest/api.html

Example usage

In the following examples, the dynamixel_id, port and baudrate values should be adapted depending on your configuration:

• for Linux users:

  • the port value should be something like

    • “/dev/ttyS0”, “/dev/ttyS1”, … if you use an actual serial port

    • “/dev/ttyUSB0”, “/dev/ttyUSB1”, … if you use an USB to serial adapter (like the USB2Dynamixel adapter)

  • the baudrate value should be the same than the one configured in Dynamixel units

• for Windows users:

  • the port value should be something like “COM2”, “COM3”, … (see the COM port configuration in the Windows device manager)

  • the baudrate value should be the same than the one configured in the Dynamixel units and the Windows device manager (i.e. check the COM port configuration in the Windows device manager)

• for MacOSX users:

  • the port value should be something like “/dev/tty.usbserial-XXX” if you use an USB to serial adapter like the USB2Dynamixel adapter

  • the baudrate value should be the same than the one configured in Dynamixel units

If you use the USB2Dynamixel device, make sure its switch is set on “TTL”.

Some other examples are available in the examples directory.

Ping a Dynamixel

This snippet prints True if the specified Dynamixel unit is connected and available at the given baudrate; otherwise it prints False.

from pyax12.connection import Connection

# Connect to the serial port
serial_connection = Connection(port="/dev/ttyUSB0", baudrate=57600)

dynamixel_id = 3

# Ping the third dynamixel unit
is_available = serial_connection.ping(dynamixel_id)

print(is_available)

# Close the serial connection
serial_connection.close()

Scan (search available Dynamixel units)

This snippet prints the ID list of connected and available Dynamixel units (at the given baudrate).

from pyax12.connection import Connection

# Connect to the serial port
serial_connection = Connection(port="/dev/ttyUSB0", baudrate=57600)

# Ping the dynamixel unit(s)
ids_available = serial_connection.scan()

for dynamixel_id in ids_available:
    print(dynamixel_id)

# Close the serial connection
serial_connection.close()

Print the control table of the first Dynamixel unit

This snippet prints the control table of the specified Dynamixel unit (i.e. the internal state information of the Dynamixel unit).

from pyax12.connection import Connection

# Connect to the serial port
serial_connection = Connection(port="/dev/ttyUSB0", baudrate=57600)

dynamixel_id = 1

# Print the control table of the specified Dynamixel unit
serial_connection.pretty_print_control_table(dynamixel_id)

# Close the serial connection
serial_connection.close()

This snippet should print something like that:

model_number................. AX-12+
firmware_version............. 24
id........................... 1
baud_rate.................... 57142.9 bps
return_delay_time............ 500 µs
cw_angle_limit............... -150.0° (0)
ccw_angle_limit.............. 150.0° (1023)
max_temperature.............. 70°C
min_voltage.................. 6.0V
max_voltage.................. 14.0V
max_torque................... 1023
status_return_level.......... 2 (respond to all instructions)
input_voltage_alarm_led...... off
angle_limit_alarm_led........ off
overheating_alarm_led........ on
range_alarm_led.............. off
checksum_alarm_led........... off
overload_alarm_led........... on
instruction_alarm_led........ off
input_voltage_alarm_shutdown. off
angle_limit_alarm_shutdown... off
overheating_alarm_shutdown... on
range_alarm_shutdown......... off
checksum_alarm_shutdown...... off
overload_alarm_shutdown...... on
instruction_alarm_shutdown... off
down_calibration............. 46
up_calibration............... 972
torque_enabled............... yes
led.......................... off
cw_compliance_margin......... 0.3° (1)
ccw_compliance_margin........ 0.3° (1)
cw_compliance_slope.......... 9.4° (32)
ccw_compliance_slope......... 9.4° (32)
goal_position................ -0.1° (511)
moving_speed................. 512
torque_limit................. 1023
present_position............. -0.1° (511)
present_speed................ 0
present_load................. 0
present_voltage.............. 12.1V
present_temperature.......... 43°C
registred_instruction........ no
moving....................... no
locked....................... no
punch........................ 32

Move the first Dynamixel unit to various position angles

This snippet moves the first Dynamixel unit to 0°, then -45°, -90°, -135°, -150° (the maximum CW angle), +150° (the maximum CCW angle), +135°, +90°, +45° and finally goes back to 0°.

from pyax12.connection import Connection
import time

# Connect to the serial port
serial_connection = Connection(port="/dev/ttyUSB0", baudrate=57600)

dynamixel_id = 1

# Go to 0°
serial_connection.goto(dynamixel_id, 0, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to -45° (45° CW)
serial_connection.goto(dynamixel_id, -45, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to -90° (90° CW)
serial_connection.goto(dynamixel_id, -90, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to -135° (135° CW)
serial_connection.goto(dynamixel_id, -135, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to -150° (150° CW)
serial_connection.goto(dynamixel_id, -150, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to +150° (150° CCW)
serial_connection.goto(dynamixel_id, 150, speed=512, degrees=True)
time.sleep(2)    # Wait 2 seconds

# Go to +135° (135° CCW)
serial_connection.goto(dynamixel_id, 135, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to +90° (90° CCW)
serial_connection.goto(dynamixel_id, 90, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go to +45° (45° CCW)
serial_connection.goto(dynamixel_id, 45, speed=512, degrees=True)
time.sleep(1)    # Wait 1 second

# Go back to 0°
serial_connection.goto(dynamixel_id, 0, speed=512, degrees=True)

# Close the serial connection
serial_connection.close()

Bug reports

To search for bugs or report them, please use the PyAX-12 Bug Tracker at:

https://github.com/jeremiedecock/pyax12/issues

Related libraries

Other libraries to control Dynamixel AX-12+ actuators are referenced in the following (non comprehensive) list:

• PyPot by Inria (FLOWERS team)

• PyDynamixel by Richard Clark

• Pydyn by Fabien Benureau and Olivier Mangin (Inria FLOWER team)

• Dynamixel by Ian Danforth

• dynamixel_hr by Romain Reignier

• python_dynamixels by Jesse Merritt

• ax12 by Thiago Hersan

• Dynamixel Monitor by Christian Balkenius

• DynamixelMonitor by Slavik

License

The PyAX-12 library is provided under the terms and conditions of the MIT License.