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.


Video.





13 comments:

  1. I know this is old, and maybe you've abandoned this blogspot already, but i wanna ask if CM-730 from darwin op can detect XL-320?
    Thanks in advance

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  2. If it works with the AX-12's then it will work with the XL-320, they use the same exact protocol.

    You just need to change the voltage from 12v to 7.4v

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    Replies
    1. hello sir, i have try this with 2 battery and 2 OpenCm. battery 3 cell for Ax-12 and battery 2cell for XL-320. But why only xl-320 that was running. and AX-12 only get power but not data. would you like to explain to me. whats wrong with this?

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    2. The point of this project was to only use one battery. A 12v battery. If you are using two batteries at the same time then there is some confusion.

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    3. my wiring like this :
      (+)12v battery to (+) AX-12
      (-)12v battery to (-)7.4v battery & to (-)AX-12 & (-)XL-320
      data AX-12 to data XL-320 and data of OpenCM.

      what do you thing about this? would you like to explain to me, what should i do, if i dont have the regurator?

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    4. or what do you thing if i use 5V for XL-320? so i can use ubec regurator for this system.

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    5. Your setup should work. Did you assign the AX-12 and the XL-320 different IDs? If they are using the same ID there will be a conflict.

      I don't know if XL-320 will work at 5v, you'd have to check the specs.

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    6. yes. i have check the ID. AX-12 use ID13 and XL-320 use ID6

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    7. but if i use only one kind of servo, it is work. but if i combine both of them, only one kind of servo that was working.

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    8. This comment has been removed by the author.

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  3. This comment has been removed by the author.

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  4. This comment has been removed by the author.

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