Why displays enhance projects in Arduino - Challenge Your Understanding

Challenge - 5 Problems

❓ Predict Output

intermediate

What does this Arduino code display on the LCD?

Given the following Arduino code snippet using a 16x2 LCD, what will be shown on the display after running?

Arduino

#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);
  lcd.print("Hello, World!");
  lcd.setCursor(0, 1);
  lcd.print("Count: ");
  lcd.print(5);
}

void loop() {}

A Count: 5\nHello, World!

B Hello, World!\nCount: 0

C Hello, World!\nCount: 5

D Hello, World! Count: 5

💡 Hint

Look at the lcd.setCursor position and what is printed on each line.

The lcd.print("Hello, World!") prints on the first line. Then lcd.setCursor(0, 1) moves cursor to start of second line where "Count: " and then 5 are printed.

🧠 Conceptual

intermediate

Why do displays enhance Arduino projects?

Which of the following is the best reason why adding a display enhances an Arduino project?

A It allows the project to show information directly to the user without needing a computer.

B It makes the Arduino run faster by offloading calculations.

C It reduces the power consumption of the Arduino board.

D It automatically fixes bugs in the code.

💡 Hint

Think about how users interact with projects and what displays provide.

Displays let the project show messages, sensor readings, or status directly to the user, making it easier to understand and use without extra devices.

🔧 Debug

advanced

Why does this OLED display code show a blank screen?

This Arduino code is supposed to show "Temp: 25C" on an OLED display but the screen stays blank. What is the cause?

Arduino

#include <Wire.h>
#include <Adafruit_SSD1306.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire);

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.print("Temp: 25C");
}

void loop() {}

A Wrong I2C address used for the display.

B Missing display.display() call to update the screen.

C Text size 2 is not supported by this display.

D The display.begin() function is called with wrong parameters.

💡 Hint

After drawing text, what function must be called to show it on the OLED?

The Adafruit_SSD1306 library requires calling display.display() after drawing commands to send the buffer to the screen. Without it, the screen stays blank.

📝 Syntax

advanced

Which option fixes the syntax error in this Arduino sketch?

This code tries to print sensor values on an LCD but has a syntax error. Which option fixes it?

Arduino

#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  lcd.begin(16, 2);
}

void loop() {
  int sensorValue = analogRead(A0)
  lcd.clear();
  lcd.print("Value: " + sensorValue);
  delay(1000);
}

A Remove lcd.clear() to fix the syntax error.

B Change lcd.print("Value: " + sensorValue); to lcd.print("Value: " + String(sensorValue));

C Replace analogRead(A0) with analogRead(A0); and keep lcd.print as is.

D Add a semicolon after analogRead(A0) and use lcd.print("Value: "); lcd.print(sensorValue);

💡 Hint

Check for missing semicolons and how to print text plus numbers on LCD.

The missing semicolon after analogRead(A0) causes a syntax error. Also, lcd.print does not support adding strings and integers directly with +, so print text and number separately.

🚀 Application

expert

How many characters can a 16x2 LCD display at once?

You have a 16x2 character LCD connected to your Arduino. How many total characters can it show on screen at the same time?

A 32 characters total

B 128 characters total

C 64 characters total

D 16 characters total

💡 Hint

Multiply the number of columns by the number of rows.

A 16x2 LCD has 16 columns and 2 rows, so it can show 16 * 2 = 32 characters at once.