Why displays enhance projects in Arduino - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the display in the setup function.

Arduino

void setup() {
  [1]();
}

Drag options to blanks, or click blank then click option'

Adisplay.begin()

Bdisplay.begin

Cdisplay.start()

Ddisplay.init

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting parentheses when calling display.begin

Using display.init which is not the correct function

Using display.start which does not exist

The display library requires calling display.begin() with parentheses to initialize the display properly.

2fill in blank

medium

Complete the code to clear the display before drawing.

Arduino

void loop() {
  [1]();
  display.display();
}

Drag options to blanks, or click blank then click option'

Adisplay.clear()

Bdisplay.clearDisplay()

Cdisplay.reset()

Ddisplay.erase()

Attempts:

3 left

💡 Hint

Common Mistakes

Using display.clear() which does not clear the buffer

Using display.reset() which is not a valid function

Using display.erase() which does not exist

The correct function to clear the display buffer is display.clearDisplay().

3fill in blank

hard

Fix the error in the code to print text on the display.

Arduino

display.setCursor(0, 0);
display.[1]("Hello World");
display.display();

Drag options to blanks, or click blank then click option'

AdrawText

Bprintln

Cwrite

Dprint

Attempts:

3 left

💡 Hint

Common Mistakes

Using display.println() which is not supported by the display library

Using display.write() which prints bytes, not strings

Using display.drawText() which does not exist

The correct function to print text on the display is display.print().

4fill in blank

hard

Fill both blanks to set text size and color before printing.

Arduino

display.setTextSize([1]);
display.setTextColor([2]);
display.print("Hi");

Drag options to blanks, or click blank then click option'

A2

BWHITE

CBLACK

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using BLACK color which makes text invisible on black background

Using text size 2 when smaller text is needed

Confusing text size with color values

Text size 1 is the default small size, and WHITE is the color to make text visible on a black background.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps words to their lengths if length is greater than 3.

Arduino

auto lengths = [1]: [2] for (auto& word : words) if ([3] > 3);

Drag options to blanks, or click blank then click option'

Aword

Bword.length()

Dwords

Attempts:

3 left

💡 Hint

Common Mistakes

Using words as key instead of word

Using word instead of word.length() for value

Using wrong condition variable

The dictionary maps each word to its length, and the condition checks if the length is greater than 3.

Practice

1. Why is adding a display to an Arduino project helpful?

easy

A. It shows information clearly to users.

B. It makes the Arduino run faster.

C. It reduces the power consumption.

D. It replaces the need for sensors.

Solution

1. Step 1: Understand the role of a display

   A display shows data or messages so users can see what the project is doing.

2. Step 2: Compare other options

   Displays do not speed up the Arduino, reduce power, or replace sensors.

3. Final Answer:

   It shows information clearly to users. -> Option A

4. Quick Check:

   Displays improve user interaction = D [OK]

Hint: Displays show info clearly to users [OK]

Common Mistakes:

• Thinking displays speed up the Arduino
• Believing displays save power
• Confusing displays with sensors

2. Which Arduino code snippet correctly initializes a 16x2 LCD display using the LiquidCrystal library?

easy

A. LiquidCrystal lcd(2, 3, 4, 5, 11, 12);

B. LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

C. LiquidCrystal lcd(5, 4, 3, 2, 12, 11);

D. LiquidCrystal lcd(11, 12, 2, 3, 4, 5);

Solution

1. Step 1: Recall the correct pin order for LiquidCrystal

   The constructor LiquidCrystal(rs, enable, d4, d5, d6, d7) uses pins in this order.

2. Step 2: Match the correct pin sequence

   LiquidCrystal lcd(12, 11, 5, 4, 3, 2); matches the standard example: 12 (rs), 11 (enable), 5, 4, 3, 2 (data pins).

3. Final Answer:

   LiquidCrystal lcd(12, 11, 5, 4, 3, 2); -> Option B

4. Quick Check:

   Correct pin order = B [OK]

Hint: Remember LiquidCrystal pins: rs, enable, d4, d5, d6, d7 [OK]

Common Mistakes:

• Mixing up pin order
• Using wrong pin numbers
• Confusing enable and rs pins

3. What will the following Arduino code display on a 16x2 LCD?

lcd.begin(16, 2);
lcd.print("Temp: ");
lcd.print(25);
lcd.print(" C");

medium

A. Temp 25 C

B. Temp: 25C

C. Temp: 25 C

D. Temp:25 C

Solution

1. Step 1: Analyze lcd.print statements

   First prints "Temp: ", then number 25, then " C" with spaces as given.

2. Step 2: Combine printed parts

   Combined output is exactly "Temp: 25 C" with spaces after colon and before C.

3. Final Answer:

   Temp: 25 C -> Option C

4. Quick Check:

   Printed strings + number = A [OK]

Hint: Check spaces in print strings carefully [OK]

Common Mistakes:

• Ignoring spaces in strings
• Assuming no space after colon
• Confusing number and string concatenation

4. This Arduino code is meant to show "Hello" on the LCD but shows nothing. What is the error?

lcd.print("Hello");
lcd.begin(16, 2);

medium

A. lcd.print() should be lcd.write()

B. lcd.print() needs a delay after it

C. lcd.begin() should be lcd.init()

D. lcd.begin() must be called before lcd.print()

Solution

1. Step 1: Check initialization order

   lcd.begin() sets up the display and must be called before printing.

2. Step 2: Identify the error in code order

   Code calls lcd.print() before lcd.begin(), so nothing shows.

3. Final Answer:

   lcd.begin() must be called before lcd.print() -> Option D

4. Quick Check:

   Initialize display first = C [OK]

Hint: Always call lcd.begin() before printing [OK]

Common Mistakes:

• Calling print before begin
• Thinking delay fixes display
• Confusing print and write methods

5. You want to show sensor readings and status messages on a display. Which approach best improves user experience in an Arduino project?

hard

A. Use a display to show real-time sensor data and clear status updates.

B. Only use serial monitor for debugging, no display needed.

C. Print sensor data to the display without clearing old text.

D. Use LEDs instead of a display for all messages.

Solution

1. Step 1: Consider user interaction needs

   Real-time sensor data and clear status messages help users understand the project easily.

2. Step 2: Evaluate other options

   Serial monitor is not user-friendly for all users; not clearing display causes confusion; LEDs can't show detailed info.

3. Final Answer:

   Use a display to show real-time sensor data and clear status updates. -> Option A

4. Quick Check:

   Clear, real-time info improves experience = A [OK]

Hint: Show clear, live data on display for best UX [OK]

Common Mistakes:

• Relying only on serial monitor
• Not clearing display before updates
• Using LEDs for detailed messages