TECHNICAL SUPPORT
Published 2026-03-17
Have you ever encountered this situation? Even though I have connected the wiring according to the instructions, theservodoes not move at all, or shakes like a sieve. When I first came into contact withservos, none of these problems occurred. After struggling all night and browsing the forum, I slowly figured out the way. The control and debugging of theservoseems simple, but there are so many details inside. Today I will have a good chat with you about the pitfalls I have stepped into and the insights I have gained over the years, hoping to save you some detours.
Connecting the wrong wires is the most common mistake for novices, and it is also the most likely reason to burn out the servo. Servos usually have three wires: power wire, ground wire and signal wire, but the color definitions of different brands may be different. I am used to using a multimeter to confirm the voltage and line sequence before wiring, and never take it for granted based on experience. Red is usually the power wire, brown or black is the ground wire, and orange or yellow is the signal wire.
Another key point is that the power supply must be "powerful" enough. The current when the servo is started is very large. If the power supply is insufficient, the voltage will be pulled down, causing the servo to be powerless or even restart. I tried using computer USB to power the high-torque servo, but the servo couldn't turn at all. Later I learned to use independent power supply, and the current of the power supply is at least 1.5 times larger than the nominal peak current of the servo, so as to ensure stable operation.
If the servo shakes, it's probably because the signal is not "clean" enough. If the PWM signal is interfered with and the duty cycle is unstable, the servo will search back and forth for position, causing jitter. I once debugged a robotic arm and the servo was shaking violently. After a long investigation, I found out that it was electromagnetic interference generated by the motor drive board. Later, a 104 capacitor was added between the signal line and the ground line, and the jitter disappeared immediately.
In addition to signals, mechanical problems can also cause jitter. For example, if the screws of the steering wheel are not tightened, or the link mechanism has a false position, the servo will correct back and forth during positioning. You need to check the entire drive system to make sure every joint is tight and smooth. Sometimes, the quality problem of the servo itself can also cause jitter, and replacing it with a better servo may solve the problem.
If you want the servo to point where to hit, you have to put some effort into the software algorithm. The frequency and duty cycle of the PWM wave generated by the microcontroller need to be accurately calculated. I found that using timer interrupts to generate PWM is much more accurate than using delay functions. In addition, adding a simple filtering algorithm, such as averaging several consecutive angle values, can effectively filter out instantaneous interference signals.
Never underestimate the impact of mechanical installation on accuracy. Even if the fixing screws of the steering wheel are loosened by a few tenths of a millimeter, the end effector will be reflected as a deviation of several millimeters or even centimeters. Before installing the steering wheel, I am used to energizing the steering gear and returning it to the neutral position, and then installing the steering wheel. This can minimize the initial error. The length and angle of the connecting rod must also be carefully adjusted to ensure a smooth range of movement.
When buying a servo, don’t be confused when faced with a bunch of parameters. Torque is the most critical, it determines how much the servo can pull. The unit is usually kg·cm, which means how many kilograms of weight can be lifted at a distance of 1 cm from the center of the steering wheel. Speed is also very important, generally expressed in seconds/60 degrees. The smaller the value, the faster it turns. Don't blindly pursue high torque, just have enough, otherwise the speed and volume will increase.
The operating voltage and angle range must also be clearly seen. Ordinary servos generally work at 4.8V to 6V, and digital servos may support higher voltages to obtain greater torque. The angle range is divided into 180 degrees and 360 degrees. The 180-degree servo cannot rotate continuously, but the 360-degree one can. I once bought the wrong one and used the 180-degree one on a wheeled car. As a result, it could only turn half a circle, which was very embarrassing.
Nowadays, many steering gear manufacturers have their own debugging software, such as "Servo" or "Servo" of a certain company. Through these software, you can easily control the servo through the computer without writing a line of code. The software interface is generally very intuitive. Drag the slider to rotate the servo to any angle. You can quickly verify whether the servo is good or not and whether the mechanical structure interferes with it.
Another advantage of using debugging software is that you can finely adjust the "neutral position" and "dead zone" of the servo. If the center position is inaccurate, the servo will move to one side; if the dead zone is set too large, there will be no response to small angle changes. I used software to repeatedly adjust these parameters until the servo response completely met my expectations. It is strongly recommended that you use software to thoroughly understand the servo before writing code, which can save a lot of debugging time.
When choosing a servo, you can't just look at the parameter list, you have to start from your actual application. Is it a robot joint or a camera gimbal? Robot joints require high torque and impact resistance; camera gimbals require smooth rotation and low noise. Plastic gear servos are cheap but easy to scan the teeth, while metal gear servos are durable but expensive and heavy. You have to find a balance between performance and cost.
In addition, don’t neglect after-sales service and technical support. I bought a servo from a small manufacturer, but if there was a problem, no one would even ask. Now I will give priority to brands that provide detailed technical documentation and official technical support. If you encounter a problem that cannot be solved, you can go directly to their company's official website to consult with technical personnel, or download the latest debugging software, so that you can feel at ease.
What's the weirdest problem you've ever encountered during servo debugging? Welcome to share your experience in the comment area. If you find the article useful, please give it a like and share it with more friends who need it!
Update Time：2026-03-17
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