The servo keeps rotating forever

Question

I have 3 servo motors in my robot arm controlled by Raspberry Pi3 B+.

One of the servos is (HV5932MG) (Link: "https://www.banggood.com/JX-Servo-PDI-HV5932MG-30KG-Large-Torque-360-High-Voltage-Digital-Servo-p-1074871.html?cur_warehouse=CN" ) which rotates (0>>360 degrees)

all servos are working excellent except for this one, it keeps rotating around itself forever without stopping regardless of the given angle.

For example, for given sequence of angles (0:360) increased by +5 degrees and then the opposite (360:0) -5 >>>> The motor rotates about (6 cycles=2160 degrees) clockwise then it begins to rotate in the opposite direction!!

I tried to change the controller, the power supply and checked the code (which works for the other servos!) with no vain.

Also I tried setting the angles to (0:10 +1) but yet it rotates about (4 cycles!!)

Has anyone faced such a problem? Does it mean the servo is defective?!

Answer 1

The servo you link is a continuous rotation servo.

A normal servo goes to a commanded angle and stays at that angle.

A continuous rotation servo goes to a commanded speed and stays at that speed.

Generally 1500µs pulses stop a continuous rotation servo, >1500 rotates clockwise, <1500 rotates counter clockwise. The further from 1500 the faster the speed.