The USB2AX is a small, programmable USB interface to the TTL Dynamixel bus (the one used by the AX and the new MX Dynamixel series). It can communicate with the servos at up to 1Mbaud. The default behavior can be either a USB2Dynamixel replacement (virtual serial only, will not work with software relying on the FTDI API) or a simple USB to serial board, yet it can also be reprogrammed as a full controller.

At its core is an ATMega32u2, an USB-enabled 8bit MCU with 32KB of FLASH, 2.5KB of RAM and 1KB of EEPROM, running at 16MHz.

All versions have basically the same functionalities, but differences in term of size, ease of fabrication, cost and design.

A dozen of the V1 board have been made with good results, and used extensively in the Xachikoma robot. They have now been replaced with V3.0a boards.

All files (Eagle schematics and board, firmware) are available in the git repository: https://www.assembla.com/code/paranoidstudio/git/nodes

If you are interested in getting one, you can contact us at  contact {at} paranoidstudio (dot) com 

Versions

V3, The latest version with smaller components, cleaner and better design.

V1 and V2, the original:

V0 and a handmade V1, the early tests or "a lesson in ghetto prototyping".

Acknowledgments

USB2AX is powered by the awesome LUFA library written by Dean Camera.

Design inspired by Atmega32u4 Breakout Board+ and Arduino Uno.

License

While all the files are not yet cleanly marked with a license, consider it to be CC-BY-SA for schematics/board, and LGPL for the code written by us. Parts written by others may be included for convenience but remain under their original license, stated in the corresponding file.

The goal is to get to a point where we can use the OSHW 1.0 license for the hardware, but we haven't had time to check everything about it.

Contributors

Xevel - Idea, original schematics, firmware (based on a LUFA example and inspired by the Arbotix)

JLG - Eagle schematics and routing

Richard Ibbotson (iBot) - optimization of the code for lower latency, improvements to the schematics.