Dynamixel Plugin Help

 
#1

DJ,

The updated Dynamixel plugin is great!

This is not a bug report but a request for an additional capability: 'Adjust AX-12 endpoints'.

I have struggled (off and on) for over a year to get a biped robot fully operational using AX-12 servos driven from an EZ-B. I think that with an 'end point conversion' addition to the plugin my goal can be reached.

If the Global Max Servo Positions set to 1024 the servo position will be as shown in the Robotis manual entry for the AX-12 servos.
An EZ-B of input value of 512, moves the servo to the top (150*)
An input of 1024 moves the servo to 300* (full CCW)
An input of 0 moves the servo to 0* (full CW)

If the Global Max Servo Positions set to 180 the servo positions will be:
An input value of 90 moves the servo to the top (90*) position. (GREAT!)
An input value of 0 moves the servo to the -60* position. (NOT 0*)
An input of 180 moves the servo to the 240* position. (NOT 180*)

I would like to set a value for an AX-12 (V1) and get the same position as an EZ-B servo (D1). That is, input the angle as a EZ-B value and get that angle deflection on the servo.

You can convert the EZ-B values to the desired AX-12 positions with these conversions:

Note: (180/300=.6)

Take the EZ-B value ,difference from 90*, multiply that difference by .6 then add or subtract that result to/from 90.

Values > 90 Multiply the value 90 *.6 and add that to 90
Example: The AX-12 desired deflection is 180*.
Then: 90+(180-90)*.6 = 144. That EZ-B value results in the AX-12 position of
180*

Values < 90 Multiply the value 90 *.6 and subtract from 90
Example: The AX-12 desired deflection is 0*.
Then: 90-(90-0)*.6 = 36. That EZ-B value results in the AX-12 position of
0*

I hope this makes sense.

#2

Thanks Smile

This isn't required assistance so i've removed that status. Please do not request assistance for feature requests.

#3

DJ,
Noted.