Operation process：
Servo control method:
The servo of the servo is controlled by variable width pulses, the control line is used to transmit the pulses. The parameters of the pulses are minimum, maximum and frequency. In general, the reference signal of the servo has a period of 20 ms and a width of 1.5 ms. The position defined by this reference signal is the middle position. The servo has a maximum rotation angle and the middle position is defined as the exact same amount from this position to the maximum angle as the minimum angle. The most important point is that the maximum angle of rotation may be different for different servos, but the width of the pulse at its intermediate position is a certain amount, which is 1.5ms.
The angle is generated by a continuous pulse from the control line. This method of control is called pulse modulation. The length of the pulse determines how much the servo will turn. For example, a 1.5 ms pulse will get to the middle of the rotation (for a 180° servo, this is the 90° position). When the control system issues a command to move the servo to a certain position and to keep it at that angle, the external forces will not cause the angle to change, but this is subject to an upper limit, which is the maximum torque. The angle of the rudder will not remain constant unless the control system keeps sending out pulses to stabilise the angle of the rudder.
When the rudder receives a pulse of less than 1.5ms, the output shaft will rotate counterclockwise by a certain angle, using the middle position as the standard. The opposite is true for pulses received greater than 1.5ms. Different brands, or even different servos of the same brand, will have different maximum and minimum values. Generally speaking, the minimum pulse is 1ms and the maximum pulse is 2ms.
To summarise.
Firstly, the leads of the servos are generally controlled by three wires (no contact has been made with those that are not three wires), red for power, brown for ground and yellow for signal. When controlling the servo, you need to keep giving PWM waves in order to make the servo have torque at a certain angle.