How To Wire The Servo? Remember Red Positive, Black Negative, Yellow Signal Line

For those who are new toservos, the most common question they encounter is "Where should I plug this wire in?" The three wires may seem simple, but if they are plugged in wrongly, they may not turn, or they may burn out. Today we will thoroughly talk about this matter. Whether you are making a robot, a smart car, or making some creative inventions, after reading this article, you will definitely be able to understand the wiring of theservo.

The three wires of the steering gear each perform their own duties.

Although there are many wires, there are actually only three wires in total, and the colors of these three wires are very particular. Among them, the most common brown or black wire is the ground wire, which is the negative pole in the circuit. The red wire is the positive terminal of the power supply, and its function is to provide power support for the steering gear. The orange or yellow line is the signal line, which is specially used to receive control instructions. Remember a simple formula "red is positive, black is negative, yellow signal", and if you follow this operation, there will be basically no mistakes. You might as well take a multimeter to measure it, so that you can verify this rule.

In actual operation, when faced with many lines, even if they seem complicated, as long as you keep in mind the characteristics and color correspondence of these three lines, you can easily deal with it. The brown or black ground wire serves as the negative pole and bears the important responsibility of stabilizing the circuit foundation; the red power supply positive pole continuously delivers power to the steering gear to ensure its normal operation; the orange or yellow signal wire accurately receives control instructions, allowing the entire system to operate according to the preset program. Through the measurement and verification of a multimeter, we can deepen our understanding and memory of this rule, so that we can become more comfortable in related operations.

The power supply voltage must be checked correctly

After connecting the wires, many friends found that theservohad no response or vibrated extremely badly. In this case, there is most likely a problem with the power supply voltage. Take ordinary small servos, such as the SG90, whose rated voltage is between 4.8V and 6V. It is just right to directly connect to a 5V USB power supply.

However, for high-torque servos, for example, the voltage range can reach 6V to 7.4V. If it is directly plugged into 5V, it will feel insufficient power. I would like to suggest that you first check the parameter list of the servo model, or pay attention to the relevant information printed on the casing, and do not make connections based on subjective feelings alone.

The signal cable will only work if it is connected to the right place

Connecting the power supply is only the first step of the entire operation process, and the signal line must be connected to a specific location that can generate PWM waves. In short, PWM is actually a signal in the form of a square wave. Its high and low changes are like breathing. The servo determines the angle to which it should rotate based on the duration of the high level. As far as the PWM wave is concerned, it is the pins marked with "~" that generate the PWM wave; for the Raspberry Pi, either a dedicated PWM pin is required, or simulation can be achieved with the help of software. If you notice that the servo is spinning randomly or not responding, the first thing to check is whether the signal line is plugged into a pin that supports PWM.

Don’t ignore the issue of shared land

This is a pitfall that is particularly common and easily overlooked in related operations: the control board and servo must be on the same ground. So what does this mean? In fact, the GND on the control board needs to be connected to the negative pole of the servo power supply. Once there is no connection, the voltage on the signal line loses its reference point. At this time, the signal received by the servo is like an out-of-focus photo, completely blurry. So pay attention when you are wiring. After the red and black wires are connected correctly, then lead a ground wire from the control board to the negative pole of the servo power supply, and you are done.

In actual operation, this common ground link is crucial. Because once the control board and servo are not grounded together, serious problems will occur in the signal transmission of the entire system. As mentioned above, if the voltage on the signal line lacks a reference point, the signal received by the servo will become chaotic and unable to work properly. Therefore, you must strictly follow the requirements. After connecting the red and black wires, accurately connect the ground wire from the control board to the negative pole of the servo power supply to ensure that the control board and servo are grounded together to ensure that the entire system can operate stably and normally.

Independent power supply is more stable

If you notice that the control panel restarts or the screen flashes when the servo is running, it means that the power supply is insufficient. The instantaneous current when the servo is started is relatively large. If it shares the same power supply with the control board, the voltage will be pulled down.

The solution this time is quite simple: provide separate power supply to the steering gear. For example, you can use one set of batteries to power the servos exclusively, and another set of batteries to power the control board or via USB, and then just connect the ground wires on both sides together. In this way, it can not only ensure sufficient power supply, but also prevent the two from interfering with each other.

Do a little test before taking action

No matter what type of servo you are using, before officially installing it on your project, it is recommended that you test it in the simplest way. You can find a piece, properly connect the power and ground, connect the signal line to the PWM pin, and then burn a simple "swing back and forth" code. If the servo can swing normally, it means there is no problem with the wiring or servo; if the servo does not respond or becomes hot, it needs to be unplugged immediately for inspection. Spending a few minutes testing like this can save hours of troubleshooting later.

When testing the steering gear, pay attention to the standardization of operation. For example, when connecting power and ground, be sure to ensure that the connection is stable to avoid looseness leading to poor contact. When connecting the signal line to the PWM pin, you should also check the pin number carefully to prevent incorrect connection. When burning code, make sure the connection to the computer is normal and the software settings are correct. Only by carrying out rigorous preparations before testing can we more accurately judge whether the steering gear is normal, thereby avoiding various subsequent problems that may arise and making the entire project progress more smoothly.

After reading so much, do you want to give it a try? If you are working on a project that requires a servo, please feel free to chat about your wiring ideas or problems you encounter in the comment area, and we will help you out!