Getting Started with Arduino Servo Motors: A Practical Guide

#include <Servo.h>

Servo myServo;

void setup() {
  myServo.attach(9);  // Signal wire on pin 9
}

void loop() {
  // Sweep from 0 to 180 degrees
  for (int angle = 0; angle <= 180; angle++) {
    myServo.write(angle);
    delay(15);  // 15ms per degree for smooth motion
  }

  // Sweep back from 180 to 0
  for (int angle = 180; angle >= 0; angle--) {
    myServo.write(angle);
    delay(15);
  }
}
```python
Upload this sketch, and your servo should sweep smoothly from one extreme to the other.

## Understanding PWM and Servo Control

Servos expect a PWM signal with a period of 20ms (50Hz). The pulse width determines the angle:

- **1ms pulse** → 0 degrees
- **1.5ms pulse** → 90 degrees (center)
- **2ms pulse** → 180 degrees

The Arduino `Servo.h` library handles this timing for you, but understanding the underlying mechanism helps when troubleshooting or working with non-standard servos.

## Controlling Multiple Servos

The Arduino UNO can control up to 12 servos simultaneously. Here's how to drive two servos independently:

```cpp
#include <Servo.h>

Servo panServo;
Servo tiltServo;

void setup() {
  panServo.attach(9);
  tiltServo.attach(10);
}

void loop() {
  panServo.write(90);   // Center position
  tiltServo.write(45);  // 45-degree tilt
  delay(1000);

  panServo.write(0);
  tiltServo.write(90);
  delay(1000);
}
```python
## Common Issues and Solutions

### Servo Jittering

If your servo vibrates or jitters at rest, try these fixes:

1. **Add a capacitor**: Place a 100µF electrolytic capacitor across the servo's power and ground lines
2. **Use external power**: The Arduino's 5V regulator can only supply about 500mA. Multiple servos need a dedicated 5V supply
3. **Detach when idle**: Call `myServo.detach()` when the servo doesn't need to hold position

### Servo Not Reaching Full Range

Some servos don't respond to the standard 1-2ms pulse range. Use `attach()` with custom microsecond values:

```cpp
myServo.attach(9, 500, 2500);  // Extended range
```python
## Practical Project: Simple Robotic Gripper

Let's build something useful. A two-servo gripper uses one servo for the grip and another for wrist rotation:

```cpp
#include <Servo.h>

Servo gripServo;
Servo wristServo;

const int GRIP_OPEN = 10;
const int GRIP_CLOSED = 80;

void setup() {
  gripServo.attach(9);
  wristServo.attach(10);
  Serial.begin(9600);
  gripServo.write(GRIP_OPEN);
  wristServo.write(90);
}

void loop() {
  if (Serial.available()) {
    char cmd = Serial.read();
    switch (cmd) {
      case 'o': gripServo.write(GRIP_OPEN); break;
      case 'c': gripServo.write(GRIP_CLOSED); break;
      case 'l': wristServo.write(0); break;
      case 'r': wristServo.write(180); break;
      case 'n': wristServo.write(90); break;
    }
  }
}