How to Use Servo: Examples, Pinouts, and Specs

A servo motor is a rotary actuator or linear actuator that allows for precise control of angular or linear position, velocity, and acceleration. It consists of a suitable motor coupled to a sensor for position feedback. Servo motors are widely used in robotics, radio-controlled cars, airplanes, and boats, as well as in industrial applications, such as controlling the motion of robotic arms. The control signal is a digital PWM (Pulse Width Modulation) signal, which determines the position of the shaft of the servo motor.

• Voltage Range: Typically 4.8V to 6V for standard servos.
• Current Consumption: Varies with load, typically up to 1A at peak for standard servos.
• Torque: Depends on the model, can range from 1.5 kg-cm to 20 kg-cm or more.
• Speed: Varies by model, with typical speeds from 0.10 to 0.20 seconds per 60-degree movement.
• Rotation Angle: Usually 0 to 180 degrees, some servos offer more extended ranges.
• Control Signal: PWM, typically a 1-2 ms pulse every 20 ms corresponds to 0-180 degrees.

1. Connect the VCC pin to a suitable power supply (4.8V to 6V).
2. Connect the GND pin to the ground of the power supply.
3. Connect the SIGNAL pin to a PWM-capable pin on your microcontroller, such as an Arduino UNO.

• Ensure that the power supply can handle the current requirements of the servo.
• Avoid stalling the servo as it can lead to high current draw and potential damage.
• Use a separate power supply if the servo's current draw is too high for the microcontroller's voltage regulator.
• Keep the control signal within the specified pulse width range to prevent damage to the servo.

#include <Servo.h>

Servo myservo;  // create servo object to control a servo

void setup() {
  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
}

void loop() {
  myservo.write(90);  // sets the servo position to 90 degrees
  delay(1000);        // waits for the servo to reach the position
  myservo.write(0);   // sets the servo position to 0 degrees
  delay(1000);        // waits for the servo to reach the position
}

• Servo not moving: Check the power supply and connections. Ensure the control signal is being sent correctly.
• Erratic movement: This can be caused by an inadequate power supply or noise in the control signal. Ensure a stable power source and signal.
• Overheating: Continuous operation under load or stalling can cause overheating. Allow the servo to cool down.

• Use a multimeter to check for proper voltage at the servo's power pins.
• If using long wires, consider using a twisted pair for the signal and ground to reduce noise.
• For high-power servos, use a dedicated power supply and ensure all connections are secure.

Q: Can I control a servo with a 3.3V microcontroller like an Arduino Due? A: Yes, but ensure that the servo can handle the 3.3V control signal. Some servos require a 5V signal.

Q: How can I control a servo with a higher voltage or current rating? A: Use an external power supply that matches the servo's requirements, and connect the ground of the power supply to the ground of the microcontroller.

Q: Can I control more than one servo with an Arduino? A: Yes, you can control multiple servos by using multiple PWM-capable pins and creating a Servo object for each one in your code.