And, of course, assembled Pincher Arm together with ArbotiX-M Robocontroller connected to your Rover.
1. On your computer
1.1 Flash ArbotiX-M Robocontroller board
To program Arbotix board, you can follow the Getting Started Guide from Trossen Robotics.
If everything works, open and upload the following sketch
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File -> Sketchbook -> ArbotiX Sketches -> ros
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1.2 Install Arbotix ROS drivers
You can install arbotix ROS packages from repository (ros-kinetic-arbotix package), but for the pincher gripper to work, you need to build an unrealeased 0.11.0 version which adds support for prismatic joints.
To build it, you can follow these steps:
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source /opt/ros/kinetic/setup.bash
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mkdir -p ~/ros_ws/src &&cd ~/ros_ws/src
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git clone https://github.com/corb555/arbotix_ros
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cd ~/ros_ws
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rosdep update
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rosdep install --from-paths src -iry
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catkin build
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1.3 Set Dynamixel IDs
Connect Arbotix-M board to your computer through FTDI-USB Cable​
Source your catkin workspace (either /opt/ros/kinetic or ~/ros_ws/devel depending on how you installed Arbotix ROS drivers) and run:
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arbotix_terminal
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arbotix_terminal by default, assumes the board is connected on /dev/ttyUSB0 port. If it is attached to another device, you can specify it like this:
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arbotix_terminal [PORT]
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To check which port the device connects to, you can, for instance, run dmesg -w (Ctrl+C to exit), connect the device and check kernel logs.
If you are using Ubuntu on Windows Subsytem for Linux , you need to open Device Manager and look under Ports for COM port number of the device. COM[N] corresponds to /dev/ttyS[N] path. (e.g. COM4 -> /dev/ttyS4). You might need to run:
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sudo chmod 666 /dev/ttyS[N]
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A terminal prompt should appear. Type help for list of commands.
Connect the Dynamixel you want to set id to. Then type ls to see id of connected servo and mv [source] [target] to change it. For example, when the servo has id 1 and we want to set it to 2, just type mv 1 2.
On PhantomX pincher arm, servo ids should look like this:
source: trossenrobotics.com
When done, type Ctrl+C to exit terminal
1.4 Test Arbotix ROS drivers
We will create a package that tests arbotix driver. Let's start by creating an empty package
Inside your package, create config/test.yaml file with following content (change port if needed):
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port: /dev/ttyUSB0
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rate:15
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joints:{
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servo1:{id:1},
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servo2:{id:2},
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servo3:{id:3},
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servo4:{id:4},
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servo5:{id:5}
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}
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You can set more parameters for each joint, like maximum speed, minimum and maximum angle etc. A brief documentation (Unfortunately, a little outdated) can be found here​
You should see command topics that let you set position (in radians) for each servo and joint_states topic that informs about position and velocity of each joint. There should also be services that allow enabling, relaxing or setting speed (in radians/sec) for each servo.
Let's try to move servo1 joint.
First, set speed to a safe value (0.2 r/s in this case):
To use this packages with PhantomX Pincher, you need to have TURTLEBOT_ARM1 environment variable set to pincher . To set it automatically on every terminal session, add export command to .bashrc file:
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echo"export TURTLEBOT_ARM1=pincher">> ~/.bashrc
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source ~/.bashrc
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Make sure to have roscore running, then type:
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roslaunch turtlebot_arm_bringup arm.launch
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This should run Arbotix driver, robot_state_publisher and set robot_description parameter.
Let's prepare a catkin workspace for pincher arm. Start by sourcing the workspace you want to extend. If you don't have an existing development workspace, just do: