PWM and analogWrite: Arduino Course 4.7

This video tutorial introduces the concept of pulse width modulation (PWM) and its application in controlling voltage output on an Arduino. The instructor uses a story about a pinwheel and a squirt gun to illustrate how PWM works by varying the duty cycle to control the speed of a DC motor or the brightness of an LED. The tutorial explains how to implement PWM using the analogWrite function on specific Arduino pins, detailing the relationship between duty cycle and apparent voltage. The video concludes with a brief overview of the analogWrite function's parameters and its ease of use.

What is the primary function of Pulse Width Modulation (PWM) in electronics?

• To decrease the resistance in a circuit

• To increase the current flow

• To switch voltage between high and low rapidly

• To create a constant voltage output

In the story, what does the Super Soaker represent in terms of duty cycle?

• No duty cycle

• A long duty cycle

• A medium duty cycle

• A short duty cycle

How does the duty cycle affect the apparent voltage seen by a circuit?

• It exponentially increases the voltage

• It is directly proportional to the voltage

• It inversely affects the voltage

• It has no effect on the voltage

What is the apparent voltage if the duty cycle is 50% and the high voltage is 5 volts?

• 5 volts

• 0 volts

• 2.5 volts

• 1.25 volts

Which Arduino pins can be used with the analog write function for PWM?

• Pins 1, 2, 3, 4, 5, 6

• Pins 2, 4, 6, 8, 10, 12

• Pins 3, 5, 6, 9, 10, 11

• Pins 7, 8, 9, 10, 11, 12

What value should be used in the analog write function to achieve a 100% duty cycle?

• 255

• 128

• 64

• 0

What is the advantage of using the analog write function without setting the pin mode?

• It increases the voltage output

• It automatically sets the pin as an output

• It reduces the code complexity

• It allows for faster execution