Re: Adafruit_PWMServoDriver how to stop sending a signal the
That's called 'hunting', and unfortunately, it's unavoidable.
Servos use a simple feedback loop with two rules:
1) if the position sensor says the rotor is too far to the left, go right.
2) if the position sensor says the rotor is too far to the right, go left.
so the feedback loop will constantly overshoot the correct position, then overcorrect the other way.
Servo control systems can improve things a little by making the amount of "go right" proportional to the amount of "too far to the left", so small offsets trigger more gentle correction.
That doesn't really solve the problem though. The system is still equivalent to a ball bearing in a hemispherical bowl. Even if the ball does end up at the exact lowest point in the bowl, there's no force keeping it there. Any small disturbance can kick it off-center again.
The formal solution is to add damping.. basically brakes. For a servo, you'd need to add a source of friction so the motor has to apply a minimum amount of torque before the rotor will actually move. Finding the right balance for that can be tricky though.