TECHNICAL SUPPORT
Published 2026-03-15
Have you just bought a few small Tower Proservos and plan to install them on your robot or remote control car, but as soon as the wires are connected and the code is transmitted, it either remains motionless or shakes like a convulsion? Don't worry, I'm very familiar with this. Almost every friend who is new to this game will get stuck on it. In fact, as long as you understand the inner way, it is not difficult to make this little thing obedient. Today we will sit down and talk about how to use the Tower Pro microservostep by step, from wiring to programming, to selection and troubleshooting, I will walk you through it all.
When I got theservo, the most confusing thing was the three thin wires. The colors are basically fixed, just remember a formula: brown (or black) is the negative pole, connected to the GND of the power supply; red is the positive pole, usually connected to the 5V power supply; orange (or yellow) is the signal line, which must be connected to the PWM output pin of your control board (image).
A special reminder here: do not plug the power supply of the servo directly into the 5V port, especially when carrying several servos at the same time. When the servo is started, the current is quite large, and it is easy to restart the board. A safe approach is to prepare a separate power supply for the servo, such as several AA batteries or a lithium battery, and then connect the negative pole of the power supply to the GND. This is called "common ground", which can ensure stable signal transmission.
In fact, it's very simple. Just imagine it as a very obedient soldier who only listens to a special "code". This signal is an electrical signal called PWM (Pulse Width Modulation). To put it bluntly, every 20 milliseconds, a high-low changing pulse is sent to it. The duration of this pulse (that is, the width of the high level) determines the angle at which the output shaft of the servo rotates.
For example, you will understand: if this high level lasts for 0.5 milliseconds, the servo's rocker arm will turn to the 0 degree position; if it lasts for 1.5 milliseconds, it will turn to the middle position of 90 degrees; if it lasts for 2.5 milliseconds, it will turn to 180 degrees. Your microcontroller is like a commander. As long as these pulse signals of different lengths are accurately sent from the signal line, the circuit inside the servo will drive the motor and move to the position you specified.
It is so convenient to use for control, because it comes with a ready-made servo library that can help you package those complex pulse signals. The code is just a few lines:
# // Introduce the servo library Servo; // Create a servo object void setup() { .(9); // Tell the program that the signal line of the servo is connected to pin 9 } void loop() { .write(0); // Command the servo to turn to 0 degrees delay(1000); // Wait for 1 second .write(90); // Turn to 90 degrees delay(1000); .write(180); // Turn to 180 degrees delay(1000); } Copy the above code into the IDE, select the correct board and port, and upload! As long as the wiring is correct and the power supply is sufficient, you will see the servo's rocker arm begin to swing back and forth. This is the most classic "waving hand" procedure, and it is also your first step in conquering the steering wheel. Doesn't it give you a unique sense of accomplishment?
Tower Pro’s two most commonly used micro servos are the SG90 and MG90S. They look similar, but their cores are different. The SG90 uses nylon plastic gears, which have the advantage of being cheap and quiet. The disadvantage is that the teeth are relatively brittle and can easily collapse under strong impact. As for the MG90S, the core gear is replaced with metal, the torque is slightly larger, and it is more durable. Of course, the price is also more expensive.
How you choose depends on your project. If you just want to make a gimbal for the camera or a shaking head fan, the SG90 is completely sufficient. But if you want to make a micro robotic arm to grab things, or use it in places that require force, it is safer to spend a few more dollars on the MG90S, so as not to have to rework after using the teeth. For specific torque parameters, it is recommended that you directly search the official website of Tower Pro and download the data sheet of the corresponding model to take a look. It is clearly written on it.
This is the "ghost hitting the wall" phenomenon most commonly encountered by novices. Nine times out of ten, the problem is with the power supply. If the servo vibrates, sounds abnormally, or does not turn at all, the first thing to suspect is the power supply. Think about it, when the servo rotates, it requires a large instantaneous current. If the power supply cannot provide it, the voltage will be pulled down instantly, causing the control board to restart or signal confusion. Then the voltage recovers and the servo wants to move again. Repeatedly, it becomes jitter.
The solution is to change to a "powerful" power supply. Don't count on the 5V port, you have to use an external power supply. For example, a 4-cell AA battery box, or a 5V voltage regulator module that can output more than 2A. Remember, the negative pole of the external power supply must be connected to GND. If it still shakes after changing the power supply, check again whether the signal line is plugged into the real PWM pin (marked with ~ on the Uno), and whether thewritevalue in the code was accidentally overwritten (it is only valid between 0 and 180).
When you learn to control a servo, it opens the door to a new world. With two servos side by side, you can make a walking bipedal robot; one up and down and one left and right, it is a two-dimensional gimbal that can track targets; three, four or even more, you can build a small multi-joint robotic arm for grabbing and carrying.
Now that you've mastered the core controls, all that's left is to use your imagination. Search the Internet for "micro servo" or go to Tower Pro's official website to look at the cases they display. You will find that there are countless ready-made drawings and codes that you can learn from. It feels absolutely great to realize your creativity with your own hands!
What fun thing did you successfully make with a servo for the first time? Or have you encountered any strange problems when tinkering with the servo? Come and share it in the comment area so that everyone can enjoy it. Also, give this article a thumbs up and share it with more friends who need it!
Update Time：2026-03-15
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