Pushbutton Digital Input With Arduino in Tinkercad

Summary

This tutorial teaches how to detect a pushbutton using an Arduino and control an LED with it. It covers both virtual and physical setup, guiding you through building a circuit with a pushbutton, LED, and resistors. You’ll learn to write simple code to read the button's state and control the LED's behavior accordingly, using digital input and if statements. The video also introduces essential concepts like pull-down resistors and provides instructions for uploading the code to an Arduino. This lesson serves as a foundation for exploring other digital inputs and furthering your Arduino journey.

Takeaways

• 😀 Learn how to detect a pushbutton using Arduino’s digital input and control an LED.
• 😀 Build a breadboard circuit with a pushbutton, LED, and resistors to interact with an Arduino.
• 😀 Use Tinkercad Circuits to simulate the circuit or work with a physical Arduino Uno setup.
• 😀 The pushbutton should be wired to 5V and pin 2 on the Arduino, with a 10K pull-down resistor to ground.
• 😀 The pull-down resistor ensures that the Arduino pin is not left floating, preventing unreliable readings.
• 😀 The basic circuit builds upon a previous example where an LED was controlled by pin 13 on the Arduino.
• 😀 Create a variable called 'buttonState' to store the status (HIGH or LOW) of the pushbutton.
• 😀 Use the 'read digital pin' function to check the state of the button and update the 'buttonState' variable.
• 😀 Use an 'if/else' statement to turn the LED on when the button is pressed (buttonState is HIGH) and off when it's not.
• 😀 The generated Arduino code can be seen in the text editor and contains 'digitalRead()', 'pinMode()', and 'if/else' functions to control the LED based on button input.
• 😀 The project introduces you to the basics of digital input in Arduino and prepares you for more complex projects, like reading analog inputs or using the serial monitor.

Q & A

What components do I need to build the circuit described in the video?

You need an Arduino Uno board, a USB cable, a breadboard, a pushbutton, an LED, resistors (including a 10K pull-down resistor), and breadboard wires.

What is the purpose of the pull-down resistor in this circuit?

The pull-down resistor provides a weak ground connection to the Arduino pin, preventing the pin from floating and ensuring that the pin is not affected by static electricity or other interference. This ensures more reliable readings.

How do you connect the pushbutton to the breadboard?

The pushbutton is placed on the breadboard, straddling the center divide. Two diagonal legs of the pushbutton should be connected: one to the 5V rail and the other to Arduino pin 2.

What is the purpose of connecting one leg of the pushbutton to pin 2 on the Arduino?

Connecting one leg of the pushbutton to pin 2 allows the Arduino to read the state of the button. When pressed, the button creates an electrical connection to the power supply (5V), which the Arduino detects as HIGH.

What does the code block 'read digital pin' do?

The 'read digital pin' block reads the voltage on a specific Arduino pin (in this case, pin 2) and stores the value as HIGH or LOW, depending on whether the button is pressed or not.

How do you check if the pushbutton is pressed in the code?

In the code, an 'if' statement checks whether the value of the variable 'buttonState' is equal to HIGH. If the button is pressed, the Arduino pin will read HIGH, and the LED will turn on.

What happens if the pushbutton is not pressed in the circuit?

If the pushbutton is not pressed, the Arduino will read LOW on pin 2, and the LED will remain off. The pull-down resistor ensures the pin reads LOW when the button is unpressed.

Why is it important to use a pull-down resistor in this setup?

The pull-down resistor ensures that the Arduino pin has a defined LOW state when the button is not pressed, preventing the pin from floating and giving unreliable readings due to electrical noise or static.

How does the program turn the LED on and off based on the pushbutton state?

The program uses an 'if' statement to check the state of the pushbutton. If the button is pressed (buttonState is HIGH), the LED is set to HIGH (on). If the button is not pressed (buttonState is LOW), the LED is set to LOW (off).

What is the significance of using 'digitalRead()' in the code?

'digitalRead()' is a function that reads the digital state of a specified pin (either HIGH or LOW). It is used here to determine if the pushbutton is pressed or not.