libezgripper

A Python library that serves as a driver to the EZGripper module designed by SAKE Robotics. This branch is compatible with Ubuntu 16.04 and Ubuntu 18.04 .

Tutorial

• On Ubuntu, install all the required dependencies. The library supports both Python 2 and Python 3:

  For Python 2

  sudo apt-get install python-serial python-qt4
  

  For Python 3

  sudo apt-get install python3-serial python3-pyqt4
  

• Install the library:

  For Python 2

  sudo pip install git+https://github.com/SAKErobotics/libezgripper.git@master
  

  For Python 3

  sudo pip3 install git+https://github.com/SAKErobotics/libezgripper.git@master
  

Quickstart

• Install the ezgripperGUI.py to your desired working directory:

  wget https://raw.githubusercontent.com/SAKErobotics/libezgripper/master/ezgripperGUI.py
  

• Launch the EZGripper GUI in python2 or python3, this should open a push-button GUI using the two base commands - calibrate and goto_position.:

  python ezgripperGUI.py
  

  or

  python3 ezgripperGUI.py
  

Usage

• In your Python program:

  from libezgripper import create_connection, Gripper
  

• Then create a connection to the gripper serial line. USB2Dynamixel usually comes up as /dev/ttyUSB*, so:

  connection = create_connection(dev_name='/dev/ttyUSB0', baudrate=57600)
  

• Now create one or more Gripper objects, according to your configuration:

  # A single gripper, with servo ID 1
  gripper = Gripper(connection, 'gripper1', [1])
  
  # Or a paired gripper, servo IDs 1 and 2
  gripper = Gripper(connection, 'gripper1', [1,2])
  
  # Or two independently controlled grippers on the same serial line
  grip1 = Gripper(connection, 'gripper1', [1])
  grip2 = Gripper(connection, 'gripper2', [2])
  

• Next, each gripper must be calibrated. The gripper will close and configure itself::

  gripper.calibrate()
  

• After calibration is done you can start moving the gripper with the method goto_position(position,effort). The parameters are:

  • position: The position in degrees, between 0 and 180.
  • effort: The effort in percent, between 0 and 100.

• Here are a few examples:

  # Open the gripper
  gripper.goto_position(100, 100)
  
  # Close the gripper
  gripper.goto_position(0, 100)
  
  # Open the gripper halfway
  gripper.goto_position(50, 100)
  
  # Close the gripper with half the force
  gripper.goto_position(0, 50)
  

Serial Port URLs

• Referencing the USB port by the device name /dev/ttyUSB0 is sometimes problematic. If you have several USB devices with similar names it is not always clear which is the one you want. And even when you find it they can switch names later. To make finding the port easier you can use hwgrep:// URLs::

  # Find the port by vendor:device id
  connection = create_connection(dev_name='hwgrep://0403:6001', baudrate=57600)
  
  # Find the port by serial number
  connection = create_connection(dev_name='hwgrep://A4012B2G', baudrate=57600)
  

• To see the properties of your serial ports the library can find try this::

  python -c "import serial.tools.list_ports;print serial.tools.list_ports.comports()"
  

• For network connected serial devices you can use the socket:// URL::

  connection = create_connection('socket://192.168.1.200:4000')