How to Use Servo mg90s: Examples, Pinouts, and Specs

The MG90S is a small, lightweight servo motor widely used in robotics, RC vehicles, and hobby projects. It features a metal gear design, which enhances durability and precision compared to plastic gear servos. The MG90S operates within a voltage range of 4.8V to 6.0V and delivers a torque of approximately 2.2 kg/cm at 6V. Its compact size and reliable performance make it ideal for applications requiring precise control of mechanical movements, such as robotic arms, pan-tilt mechanisms, and model airplanes.

• Robotic arms and grippers
• Pan-tilt camera systems
• RC vehicles and airplanes
• Automated mechanisms in hobby projects
• Educational electronics and prototyping

The MG90S servo motor has a 3-pin connector with the following pinout:

1. Power Connection: Connect the red wire to a 4.8V to 6.0V power source and the brown wire to ground. Ensure the power supply can provide sufficient current (at least 1A) to avoid voltage drops.
2. Signal Connection: Connect the orange wire to a PWM-capable pin on your microcontroller (e.g., Arduino).
3. PWM Signal: Generate a PWM signal with a pulse width between 500 µs (0°) and 2500 µs (180°). A pulse width of 1500 µs corresponds to the neutral position (90°).
4. Mounting: Use the included screws and servo horns to attach the MG90S to your project.

• Power Supply: Avoid powering the servo directly from the microcontroller's 5V pin, as it may not provide enough current. Use an external power source or a dedicated servo driver.
• PWM Frequency: The MG90S typically operates at a PWM frequency of 50 Hz (20 ms period).
• Overloading: Do not exceed the torque rating to prevent damage to the motor or gears.
• Calibration: Test the servo's range of motion to ensure it does not hit physical stops, which could cause overheating or damage.

The following example demonstrates how to control the MG90S servo using an Arduino UNO and the Servo library.

#include <Servo.h> // Include the Servo library

Servo myServo; // Create a Servo object to control the MG90S

void setup() {
  myServo.attach(9); // Attach the servo to pin 9 on the Arduino
}

void loop() {
  myServo.write(0); // Move the servo to 0 degrees
  delay(1000); // Wait for 1 second

  myServo.write(90); // Move the servo to 90 degrees
  delay(1000); // Wait for 1 second

  myServo.write(180); // Move the servo to 180 degrees
  delay(1000); // Wait for 1 second
}

• Use a capacitor (e.g., 100 µF) across the power supply to stabilize voltage.
• Avoid sudden changes in position to reduce wear on the gears.
• Test the servo with a low load before integrating it into your project.

1. Servo Not Moving:

   • Cause: Incorrect wiring or insufficient power supply.
   • Solution: Double-check the connections and ensure the power supply provides at least 1A.

2. Servo Jittering:

   • Cause: Electrical noise or unstable power supply.
   • Solution: Add a capacitor across the power supply and ensure proper grounding.

3. Limited Range of Motion:

   • Cause: Incorrect PWM signal or physical obstruction.
   • Solution: Verify the PWM pulse width and ensure the servo is not hitting any physical stops.

4. Overheating:

   • Cause: Overloading or continuous operation at high torque.
   • Solution: Reduce the load and allow the servo to cool down periodically.

Q: Can I power the MG90S directly from the Arduino's 5V pin?
A: It is not recommended, as the Arduino's 5V pin may not provide enough current. Use an external power source.

Q: What is the maximum rotation angle of the MG90S?
A: The MG90S can rotate approximately 180°.

Q: Can I use the MG90S with a Raspberry Pi?
A: Yes, but you will need to generate a 50 Hz PWM signal using a library like RPi.GPIO or a dedicated servo driver.

Q: How do I prevent the servo from jittering?
A: Use a stable power supply, proper grounding, and a capacitor to filter noise.