Description: Using the Dynamixel Shield SDK developed by Robotis link, actuates two motors that are chained together between two seperate goal points using position control. This mimics the behavior of opening and closing an end-effector.
Visualization:
Required Resources:
- Arduino (Mega or Uno)
- Power Supply Capable of Providing 12V Power to the Shield
- MX-28 & MX-64 Dynamixel Motors
- Compatible Dynamixel Wires
Required Downloads:
- Dynamixel2Arduino by Robotis v0.6.2 (via the Arduino IDE)
- DynamixelShield by Robotis v0.2.6 (via the Arduino IDE)
Description: Using the Dynamixel Shield SDK developed by Robotis link, actuates two motors that are chained together between two seperate goal points using position control. Additional functionalities are explained below.
Functionality:
| Function | Description | Purpose |
|---|---|---|
| openCutter() | Open the MX-64 motor using PID position Control | --- |
| closeCutter() | Open the MX-28 motor using PID position Control | --- |
| checkOpenGripper() | By using a difference between expected position & current position, check if the motor moved | openCutter() only ensures command was received by motor, not if it was opened |
| checkOpenCutter() | By using a difference between expected position & current position, check if the motor moved | openGripper() only ensures command was received by motor, not if it was opened |
| resetMotors() | Factory Reset and Change the IDs of each motor | If the motor becomes overtorqued/overheats/etc. it shuts down to prevent damage and cannot be used |
| pingMotors() | --- | Ensure Proper Communication is happening with motors |
| update_state() | Encoding the state of the end-effector (both open, both closed, etc.) | To be tracked by the system or a GUI |
| harvestCb() | Isolated states functionality to open, close, or some combination for autonomous or manual use over ROS | --- |
Required Resources:
- Arduino Mega
- Power Supply Capable of Providing 12V Power to the Shield
- MX-28 & MX-64 Dynamixel Motors
- Compatible Dynamixel Wires
- FTDI Chip & Compatible Cable
Required Downloads:
- Rosserial by Michael Ferguson v0.9.1 (via the Arduino IDE)
Special Notes:
Rosserial Workarounds:
- When using a breakboard and rosserial, you cannot simply use the USB port provided by Arduino as both communicate over RX/TX pins
- One solution to this is using an Arduino Mega and using the extra Hardware Serial pin, along with a standard FTDI chip
- You also need to specify which hardware pin you want to communciate over (below)
// set up the ros comms
nh.initNode();
Serial2.begin(57600);
nh.getHardware()->setPort(&Serial2);
nh.getHardware()->setBaud(57600);Rosserial Setup:
Step 1: Install Libraries
Type the following code in the terminal : (Replace Indigo with your current version of ROS)
sudo apt-get install ros-indigo-rosserial-arduino
sudo apt-get install ros-indigo-rosserialStep 2: Create Ros-Lib
cd ~/sketchbook/libraries
rm -rf ros_lib
rosrun rosserial_arduino make_libraries.py .(DO NOT FORGET THE PERIOD AT THE END)
Step 3: Start writing your program in the arduino IDE
Step 4: Run the code
Step 4.1 Run roscore in a new terminal
Step 4.2 Next, run the rosserial client application that forwards your Arduino messages to the rest of ROS. Make sure to use the correct serial port: (serial port to vary)
rosrun rosserial_python serial_node.py /dev/ttyUSB0Description: Using the Dynamixel Shield SDK developed by Robotis link, factory resets a motor using the Arduino, and changes its ID. Helpful if you don't have access to a USB2Dynamixel
Required Resources:
- Arduino (Mega or Uno)
- Power Supply Capable of Providing 12V Power to the Shield
- Single Dynamixel Motor
- Compatible Dynamixel Wires
- USB Communciation Device
Required Downloads:
- Dynamixel2Arduino by Robotis v0.6.2 (via the Arduino IDE)
- DynamixelShield by Robotis v0.2.6 (via the Arduino IDE)