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Published2025-10-15
Introduction to the SG90 Servo Motor and Its Working Mechanism
When it comes to small-scale robotics and automation, the SG90 servo motor has gained immense popularity due to its compact size, efficiency, and versatility. Whether you're building a simple robotic arm, a mobile robot, or just experimenting with different mechanisms, the SG90 provides precise control and positioning that is crucial for any project. One of the key components to understanding the SG90 servo motor lies in its pin diagram, which acts as the map to its functionality.
What is the SG90 Servo Motor?
The SG90 is a micro servo motor, widely used in various hobby and DIY electronics projects. Despite its small form factor, it delivers high torque and precise angular movement, making it ideal for tasks such as rotating parts, adjusting positions, or controlling robotic limbs. The motor operates based on a PWM (Pulse Width Modulation) signal and uses a small DC motor and a gearbox to achieve the desired motion.
Servo motors like the SG90 are position control devices, meaning they can be commanded to rotate to specific angles (typically ranging from 0° to 180°) with incredible precision. Unlike regular DC motors that only rotate continuously, servo motors can be controlled to stop at specific positions, making them extremely useful in robotics and automation.
The Importance of Understanding the SG90 Pin Diagram
Before diving into the practical applications of the SG90, it's crucial to first understand its pinout diagram. The pin diagram of the SG90 servo motor outlines the key electrical connections necessary for its operation. Typically, the SG90 has three pins: VCC, GND, and PWM (Signal). Let's explore each of these pins in more detail:
This pin provides the necessary voltage for the operation of the motor. The SG90 typically operates on a voltage range between 4.8V and 6V. Powering the servo motor with an incorrect voltage could damage the motor, so it's essential to ensure the correct power supply. Most of the time, a 5V power source is sufficient for optimal performance.
The GND pin is the reference for the power and signal inputs. It connects the negative side of the power supply to complete the electrical circuit. It’s essential to make sure the ground of the servo is connected to the ground of the controlling device, such as a microcontroller or Arduino board, to ensure proper signal transmission and motor control.
The PWM signal pin is the heart of controlling the SG90 motor. It is where the position command is sent to the servo. The PWM signal is a square wave, and its pulse width determines the angle of rotation. Typically, a pulse width between 1ms to 2ms corresponds to the servo’s rotation range from 0° to 180°. This pin is connected to a PWM output pin from a microcontroller, such as an Arduino or Raspberry Pi, which generates the signal.
How Does the SG90 Servo Motor Work?
The SG90 operates based on pulse width modulation (PWM). When the signal pin receives a pulse, the width of the pulse determines the position of the servo. A pulse width of 1ms typically corresponds to the 0° position, while a pulse width of 2ms corresponds to the 180° position. The servo motor uses an internal feedback mechanism to adjust its position based on the incoming pulse width. This allows for precise control over the angle of rotation, making it highly suitable for robotic applications where accuracy is required.
Inside the SG90, a small DC motor rotates the internal gears. The feedback system, typically a potentiometer, continuously adjusts the position of the motor to match the desired angle. This process is quick and efficient, allowing the servo to move from one position to another with minimal delay.
Power Requirements and Operational Limits
The SG90 servo motor is designed to operate within a voltage range of 4.8V to 6V. Exceeding this range could cause the motor to overheat, while lower voltages may result in insufficient torque. When connecting the SG90 to a power source, it's important to ensure the power supply can handle the motor’s current requirements.
The motor is capable of producing a torque of 1.8 kg-cm at 4.8V, making it capable of handling light-to-medium load tasks in robotics. However, it's important to note that while the SG90 is a relatively powerful servo, it is not suitable for tasks requiring high torque or heavy lifting.
Practical Applications and Wiring the SG90 Servo Motor
Now that we’ve explored the fundamental working principle and pin diagram of the SG90, it’s time to dive into its practical applications. Whether you're building a robot, a robotic arm, or an automated system, the SG90 can be used in a variety of ways. Additionally, we will go through how to wire the SG90 servo motor to a microcontroller and control it using simple code.
Practical Applications of the SG90 Servo Motor
The SG90 servo motor is incredibly versatile and finds applications in a wide range of fields:
The SG90 is a go-to choice for many robotics enthusiasts due to its precision and compact size. It’s used in robotic arms, mobile robots, and humanoid robots to control movement. The ability to rotate through a range of angles makes it suitable for joint movement and fine-tuned positioning.
In radio-controlled (RC) vehicles like cars, planes, and drones, the SG90 servo motor is used to control steering mechanisms, flight control surfaces (such as elevators and ailerons), and other moving parts.
In industrial automation, small-scale automation, or even DIY home automation projects, the SG90 is used to open/close doors, control cameras, or adjust sensors to specific angles.
Engineers and hobbyists often use the SG90 for prototype development and model-making. It’s great for testing movement, mechanics, and control systems before scaling up to more complex designs.
Wiring the SG90 Servo Motor to a Microcontroller
To control the SG90 servo motor with a microcontroller (such as an Arduino), follow these steps:
Connect the VCC pin of the SG90 to the 5V pin of the Arduino.
Connect the GND pin of the SG90 to the GND pin of the Arduino.
Connect the PWM pin of the SG90 to one of the PWM pins of the Arduino (for example, pin 9).
Once connected, you can send a PWM signal to the SG90 to control its position. To generate the correct PWM signal, you can use the Servo library in Arduino, which simplifies controlling the motor’s position with commands like servo.write().
Sample Arduino Code to Control the SG90
Servo myServo; // Create a servo object
myServo.attach(9); // Pin 9 connected to the signal pin of SG90
myServo.write(0); // Move the servo to 0° position
delay(1000); // Wait for 1 second
myServo.write(90); // Move the servo to 90° position
delay(1000); // Wait for 1 second
myServo.write(180); // Move the servo to 180° position
delay(1000); // Wait for 1 second
In this example, the servo rotates between 0°, 90°, and 180°. You can adjust these angles and timing to create more complex movements for your projects.
The SG90 servo motor is a powerful tool in the world of electronics, robotics, and automation. By understanding its pin diagram, the function of each pin, and the working principle behind its PWM control, you can unlock a vast range of possibilities for your projects. Whether you're building robots, automating systems, or creating prototypes, the SG90 offers a compact, precise, and easy-to-use solution for controlling motion in your designs.
With proper wiring and basic programming, you can harness the full potential of the SG90 servo motor to create innovative and efficient systems that are sure to impress.
Kpower has delivered professional drive system solutions to over 500 enterprise clients globally with products covering various fields such as Smart Home Systems, Automatic Electronics, Robotics, Precision Agriculture, Drones, and Industrial Automation.
Update：2025-10-15
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