Arduino Tutorial #5: PWM and Servos

Step-by-Step Tutorial: Arduino PWM and Servos

Introduction:

In this tutorial, we will explore Pulse Width Modulation (PWM) and how it can be used with Arduino to create pseudo-analog signals and control servos. We will also learn how to dim an LED using PWM and control a servo motor.

Materials Needed:

• Arduino board
• LED
• Servo motor
• Jumper wires
• Multimeter (optional)

Step 1: Understanding Pulse Width Modulation (PWM)

1. Pulse Width Modulation (PWM) creates a square wave signal with varying duty cycles.
2. Duty cycle represents the percentage of time the signal is on during each period.
3. PWM pins on Arduino are marked with a "~" symbol.
4. Varying the duty cycle allows us to create pseudo-analog signals.

Step 2: Dimming an LED using PWM

1. Connect an LED to pin 3 on the Arduino board.
2. Write the code to create a PWM signal for dimming the LED.
3. Use the analogWrite() function to control the brightness of the LED.
4. Upload the code to the Arduino and observe the dimming effect on the LED.

Step 3: Controlling a Servo Motor using PWM

1. Connect a servo motor to the Arduino.
2. Use the Servo library to control the servo motor position.
3. Adjust the PWM signal to control the angle of the servo motor.
4. Upload the servo control code to the Arduino and observe the servo motor movement.

Step 4: Troubleshooting and Adjustments

1. If using a continuous rotation servo instead of a fixed-angle servo, adjust the code to control the speed of rotation.
2. Refer to the datasheet of the servo motor for specific timing requirements.
3. Make necessary adjustments to the code to ensure proper functioning of the servo motor.

Step 5: Testing and Verification

1. Upload the code to the Arduino and observe the dimming effect on the LED and the movement of the servo motor.
2. Use a multimeter to measure the voltage output during PWM signal variations.
3. Ensure that the LED dims smoothly and the servo motor moves as expected based on the PWM signal.

Conclusion:

In this tutorial, we have learned how to use Pulse Width Modulation (PWM) to create pseudo-analog signals for dimming an LED and controlling a servo motor. By understanding PWM and its applications, you can explore more advanced projects using Arduino.

Additional Notes:

• Experiment with different duty cycles to observe varying effects on LED brightness and servo motor movement.
• Refer to online resources and communities for assistance in troubleshooting and optimizing PWM applications with Arduino.

By following these steps, you can effectively utilize PWM for controlling devices and creating analog-like signals using Arduino.