Society of Robots - Robot Forum
Mechanics and Construction => Mechanics and Construction => Topic started by: mrcw2 on May 20, 2011, 03:02:41 AM
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Hi I use a Phidgets advanced servo controller to control a Hitec HSR-1422CR servo. I can start the servo with the command
advServo.Servos[0].Engaged = True;
and stop the servo with
advServo.Servos[0].Engaged = False;.
But I decided to use a Hitec HS-5745MG for more power. I converted the servo and set the pot to the null position (servo stationary). Now the first command starts the servo, but the second command doesn't stop the servo.
Anybody got any idea what else I need to do?
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Are you able to get a full range of motion from the servo (-full_speed to +full_speed)? Stopping the signal isn't guaranteed to stop the servo - only a 1500us pulse is going to do that. The behavior when the servo is not given a signal is not defined, so it'll be inconsistent between servos.
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yes I get the full range of movement.
doesn't a 1500 us puts the servo in the centre position (not bacwards or forwards)? When I disengage the servo, in whatever position, surely it should stop/disengage. The other servo stops/disengages whatever position it's in, which is what I think this servo should do.
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Did you test the servo before modifying it?
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I don't know what advServo.Servos[0].Engaged = True; does but a servo requires a pulse about every 20msec. From a modified continuous rotation servo the 'neutral' pulse (1500us) must be send at 20ms intervals. So as rbtying said, not sending a pulse is an undefined condition and probably will not stop the servo motion.
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yes the servo worked fine before I played with it, now the servo will engeage ok but won't disengage. If I apply the correct pulse the servo will stop - which is correct. Do i want the servo to disengage? At least now If it's still engaged but on an incline, it holds it's position when stopped.
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Because that servo is a digital servo its programming may be different from the analog servo.