Servo rotation control

Lynxmotion Legged Robots
1

Hi, I’m working on a 8 D.O.F biped and I’m writing some code for it to make it walk, kick, etc. and I was wondering on how to make the servos rotate by a set amount. I’ve analyzed the biped BRAT code where it gives the array of numbers (I’ve added that part of the code to this post) and I wanted to ask what the numbers are; are they the exact degrees the servo turns through or are they some sort of ratio (as in the digit 1 represents 5 degrees of turning).

Thank You!

move: if(command = 1) then ; Walk Forward gosub movement 7.0,-20.0,-20.0, -7.0, 20.0, 20.0, 500.0] gosub movement -7.0,-20.0,-20.0, 7.0, 20.0, 20.0, 500.0] gosub movement -7.0, 20.0, 20.0, 7.0,-20.0,-20.0, 500.0] gosub movement 7.0, 20.0, 20.0, -7.0,-20.0,-20.0, 500.0]

2

I would have to look at the code, to remember exactly which parameter is which, in particular if the left or right legs parameters are first…

The first 6 parameters are for the 6 servos associated with the two legs, probably in the order (Ankle, Knee, Hip). The measurement are in degrees. So it says something like move to Ankle to 7.0 degrees. The last parameter says do this move in 500ms (1/2 second).

Note, there are some versions of the Brat code that have converted these angles from floating point numbers to fixed point numbers and I believe they specified the moves in 1/10th of a degree, so the above would be something like:

gosub movement   70,-200,-200, -70, 200, 200, 500]

Good luck
Kurt

3

Thank you!