Thursday, March 20, 2014

Chaining Dynamixel XL-320 Servos with AX-12

I've been experimenting with the XL-320 servos. Their small size and low cost make them perfect for actuating the non load bearing parts of a robot. For example, a pan/tilt camera and hand grippers. Ideally I'd like to chain the XL-320s to the existing AX-12s in my robot to save weight and space. There are a few problems though:

  • They require 7.5v versus 12v.
  • They use a Molex Micro-Latch connector instead of the Spox

I decided to build a small board that lowers the voltage and adapts the connector types. It was a little tricky finding a efficient voltage regulator that was small and powerful enough. The people on the Trossen Robotics Forums helped though. Finally settled on the SR05S7V2.

Wiring was straight forward:

AX-12 Data -> XL-320 Data
AX-12 GND -> XL-320 GND -> SR GND
AX-12 VDD -> SR V-IN
XL-320 VDD -> SR V-OUT

Some pictures.