How to Use Servo MG90S: Examples, Pinouts, and Specs

The Servo MG90S is a small, lightweight servo motor widely used in robotics, RC vehicles, and hobby electronics projects. It features a 180-degree range of motion, making it ideal for applications requiring precise angular positioning. With a torque rating of approximately 2.5 kg/cm, the MG90S is capable of handling moderate loads while maintaining compact dimensions. Its metal gear construction ensures durability and reliability, even under continuous use.

• Robotic arms and grippers
• RC vehicles (cars, boats, and planes)
• Pan-tilt camera systems
• Automated mechanisms and animatronics
• DIY hobby projects requiring angular motion control

The Servo MG90S is designed for ease of use and compatibility with a wide range of microcontrollers and power sources. Below are its key technical details:

The MG90S servo motor has a 3-pin connector for power, ground, and signal. Below is the pinout description:

1. Power Connection: Connect the red wire to a 5V or 6V 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: The servo is controlled by a PWM signal with a pulse width between 1 ms and 2 ms:
   • 1 ms corresponds to 0°.
   • 1.5 ms corresponds to 90° (center position).
   • 2 ms corresponds to 180°.

Below is an example of how to control the MG90S using an Arduino UNO:

• Connect the servo's red wire to the Arduino's 5V pin.
• Connect the brown wire to the Arduino's GND pin.
• Connect the orange wire to digital pin 9 on the Arduino.

#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
}

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
}

• Power Supply: Use a stable power source to prevent erratic behavior. Avoid powering the servo directly from the Arduino if multiple servos or high torque is required.
• PWM Signal: Ensure the PWM signal is within the specified range (1 ms to 2 ms pulse width).
• Mechanical Load: Avoid exceeding the torque rating (2.5 kg/cm) to prevent damage to the servo.

1. Servo Not Moving

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

2. Erratic or Jittery Movement

   • Cause: Noise in the PWM signal or unstable power supply.
   • Solution: Use a decoupling capacitor (e.g., 100 µF) across the power lines and ensure a clean PWM signal.

3. Servo Stuck at One Position

   • Cause: PWM signal out of range or mechanical obstruction.
   • Solution: Verify the PWM signal is within the 1 ms to 2 ms range and check for physical obstructions.

4. Overheating

   • Cause: Prolonged operation under high torque or insufficient ventilation.
   • Solution: Reduce the load on the servo and ensure proper ventilation.

Q: Can I use the MG90S with a 3.3V microcontroller?
A: Yes, but you must provide a separate 5V or 6V power source for the servo. Use a level shifter if the PWM signal voltage is too low.

Q: How many MG90S servos can I control with an Arduino?
A: The number depends on the power supply and available PWM pins. Ensure the power supply can handle the total current draw of all servos.

Q: Can the MG90S rotate more than 180 degrees?
A: No, the MG90S is designed for a maximum range of 180 degrees. For continuous rotation, consider a continuous rotation servo.

Q: What is the lifespan of the MG90S?
A: The lifespan depends on usage conditions, but the metal gears provide better durability compared to plastic gear servos. Regular maintenance and avoiding overloads can extend its life.