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Published 2026-04-16
This guide provides direct, actionable methods to stop aservomotor immediately and keep it stationary. Whether you are using a standard hobbyservoin a robotics project or an industrialservoin a control system, stopping a servo means either commanding it to hold its current position or cutting power to eliminate all torque. Below you will find verified techniques that work across common servo types, with real-world examples and clear step-by-step instructions.
A standard servo motor does not rotate continuously like a DC motor. Instead, it moves to a specific angular position based on a control signal (usually a PWM signal). Tostopa servo means to make it cease moving and stay at one angle. This is achieved by sending a fixed PWM pulse width that corresponds to the desired stationary position.
Pulse width range: Typically 1.0 ms (0 degrees / full left) to 2.0 ms (180 degrees / full right)
Neutral position (stopped at center): 1.5 ms pulse every 20 ms (50 Hz)
Real-world example: In a robotic arm,you want the gripper servo to stop after closing on an object. Sending a constant 1.5 ms signal makes the servo hold that position with full holding torque, preventing the object from falling.
This is the proper way to stop a servo while maintaining holding torque. The servo receives a continuous command to stay at the desired angle.
1. Determine the target anglewhere you want the servo to stop.
2. Generate the corresponding PWM pulse width:
For 0° → 1.0 ms pulse
For 90° (center) → 1.5 ms pulse
For 180° → 2.0 ms pulse
3. Repeat the pulse every 20 ms(50 Hz refresh rate).
4. Continue sending the same pulse indefinitely– the servo will remain stopped at that exact position.
Common case: A camera pan-tilt mechanism. After tracking a subject, you want the servo to stop and hold the camera steady. By continuously sending the 1.5 ms signal, the servo stops moving and resists external forces.
> Verification: This method follows the standard PWM servo control protocol defined by all major servo manufacturers. It works for any analog or digital servo.
If you completely stop sending control pulses, most standard servos will lose their commanded position. The result varies:
Some servos stop applying torque and become free-moving (no holding force).
Others may jitter or drift due to internal noise.
Digital servos may hold the last position briefly but will eventually relax.
Real-world example: A hobbyist left the servo signal wire disconnected while the battery was still connected. The servo arm moved freely by hand, causing a robot leg to collapse.
Actionable advice: Only use this method if you want the servo to have zero holding torque (e.g., allowing manual repositioning). Otherwise, use Method 1.
To completely stop the servo and eliminate all torque – useful in emergency stops or when the servo is fighting against a mechanism.
Disconnect the power wire (red wire)– Servo stops immediately and can be turned manually.
Use a relay or MOSFET switchcontrolled by your microcontroller to cut V+ supply.
Important: Never cut only the ground (GND) or signal wire while leaving power connected – this can create floating voltages and damage the servo or controller.
Common case: In a conveyor belt diverter, an overcurrent fault is detected. A relay cuts power to the servo, stopping it instantly to prevent mechanical damage.
Continuous rotation servos are modified to act like motors. To stop a continuous rotation servo:
Neutral signal (1.5 ms)= full stop (no rotation)
Pulse
Pulse >1.5 ms = rotate opposite direction
Example: A wheeled robot using continuous rotation servos. Sending 1.5 ms stops the wheels completely. Any deviation causes motion.
Core principle repeated: To stop a servo and keep it stationary, send a constant PWM pulse matching the desired angle – do not remove the signal unless you want zero holding torque.
Immediate action steps:
1. Identify your servo type(standard position servo or continuous rotation).
2. For standard servo: Send 1.5 ms pulse every 20 ms to stop at center; calculate pulse for other stop angles.
3. For continuous rotation servo: Send exactly 1.5 ms to achieve full stop.
4. For emergency stop: Cut power via a relay – do not rely on signal removal.
5. Always verifythe neutral pulse width empirically, as manufacturing tolerances vary (±0.05 ms).
Final recommendation: Implement a software function that continuously outputs the desired stop PWM. Never leave the signal pin floating. If you need the servo to remain stopped for long periods, consider using a servo with a digital potentiometer feedback or an absolute encoder for drift-free holding.
By following this guide, you will reliably stop any servo motor in your project, whether it’s a robotic arm, camera gimbal, RC vehicle, or industrial actuator.
Update Time：2026-04-16
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