How to connect SG90 Servo Motor with Arduino UNO

The SG90 micro servo is one of the most popular hobby servos used in robotics and automation projects. Here are its key details:

• Weight: ~9 g (very compact and lightweight).
• Operating Voltage: 4.8–6.0 V.
• Current Draw: ~100–250 mA under normal load, higher at stall.
• Rotation Range: ~0° to 180° (limited by internal mechanical stops).
• Control Signal: Pulse width modulation at ~50 Hz.
• 1 ms pulse ≈ 0°
• 1.5 ms pulse ≈ 90°
• 2 ms pulse ≈ 180°
• Wiring:
• Red → VCC (5 V)
• Brown → GND
• Orange/Yellow → Signal (Arduino digital pin)

This servo is widely used in robot arms, pan-tilt camera mounts, RC planes/cars, and small automation projects because of its low cost and ease of use.

 

 How to connect SG90 Motor to Arduino Uno

Wiring connection

• SG90 Red (VCC) → Arduino 5 V (or external 5 V supply for stability).
• SG90 Brown (GND) → Arduino GND.
• SG90 Orange (Signal) → Arduino Digital Pin 9 (commonly used).

Tip: If you plan to use multiple SG90 servos or apply load, use an external 5 V supply with sufficient current capacity, and connect its ground to Arduino’s ground.

 

 

Programming SG90 with Arduino Uno

Arduino provides a built-in Servo library that simplifies control. Below are two common examples:

1. Sweep Example (basic test)

 

#include <Servo.h>

 Servo myServo;

 void setup() {

  myServo.attach(9); // Signal pin connected to D9

}

 

void loop() {

  for (int angle = 0; angle <= 180; angle++) {

    myServo.write(angle);   // Move to angle

    delay(15);              // Small delay for smooth motion

  }

  for (int angle = 180; angle >= 0; angle--) {

    myServo.write(angle);

    delay(15);

  }

}

Output: This moves the servo back and forth across its full range.

 

  

2. Potentiometer Control (manual angle)

 

#include <Servo.h>

 Servo myServo;

int potPin = A0; // Potentiometer connected to analog pin A0

 

void setup() {

  myServo.attach(9);

}

 

void loop() {

  int potVal = analogRead(potPin);          // Read 0–1023

  int angle = map(potVal, 0, 1023, 0, 180); // Map to 0–180°

  myServo.write(angle);

  delay(10);

}

 Output: Turning the potentiometer knob sets the servo angle.

 

How It Works with Arduino

• The Arduino generates a pulse every 20 ms.
• The pulse width (1–2 ms) tells the servo what angle to hold.
• The SG90’s internal control circuit compares the shaft position (via potentiometer feedback) with the commanded angle and drives the motor until they match.
• This closed-loop system ensures precise positioning without external sensors.

  

Practical Tips

• Use external power if servo jitters or Arduino resets.
• Add capacitors (100 µF–1000 µF) across supply rails to smooth current spikes.
• Avoid forcing rotation beyond 0–180°; it can damage gears.
• Mount securely using provided horns and screws for stable operation.