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ROS2 Sync Read/Write Node for Quadruped Robot

Servo: DYNAMIXEL XM540-W270-R
Environment: ROS2 on Raspberry Pi running Ubuntu 20.04, powering the Dynamixel with 12V DC, interfacing with U2D2
Operating mode: 2M baud rate, position control
Full description:

I’m hoping to control 6 Dynamixels using sync write. I would like to accomplish this by writing a ROS2 node that listens to a topic that is publishing those 6 numbers, and the node writes the position to the nodes. Eventually I’d like to also publish the current states of the motors as well to a ROS2 topic, but I’ll take it one step at a time. I’ve found a tutorial for ROS2 using a single Dynamixel (DYNAMIXEL Quick Start Guide for ROS 2 - YouTube) but I was wondering if anyone had implemented sync read/write, as it seems like Dynamixels are pretty commonly used with ROS. Thanks!

Hello @chaniel, thanks for your post and for sharing this question!

Regarding the current ROS examples for DYNAMIXEL, unfortunately I do not believe there is a specific example video for the sync read / sync write commands at this time. While the video focuses on the read_write example from the DYNAMIXEL SDK run through ROS, it may be helpful to reference the setup instructions alongside the sync_read_write Makefile from the DYNAMIXEL SDK GitHub here.

As I am less experienced with custom ROS packages, allow me to tag our member @willson who may be able to share some additional recommendations.

Hi @chaniel

Thank you for your inquiry.
I’ll try to write a simple sync read/write example with a couple DYNAMIXEL during this weekend so that you can refer it for your project.
Thank you!