Untitled Flashcard Set

1. What does the function lcd.init() do?

Answer: Initializes communication with the LCD.

2. In the provided code, which library is used to control the LCD?

Answer: LiquidCrystal_I2C.h

3. What is the role of the line #include <Wire.h>?

Answer: It is required for I2C communication.

4. The LCD used in this example is described as “16x2.” What does that mean?

Answer: 16 characters per row, 2 rows.

5. What is the purpose of lcd.backlight()?

Answer: Turns on the LCD screen light.

6. What is the function of the SDA pin in I2C communication?

Answer: Sends and receives data.

7. Which Arduino pins are used for I2C on an Uno?

Answer: SDA → A4, SCL → A5.

8. What is the function of lcd.setCursor(0,0)?

Answer: Moves the cursor to the first row, first column.

9. What does the line pinMode(7, INPUT_PULLUP); mean?

Answer: Pin 7 is input with an internal pull-up resistor.

10. When using INPUT_PULLUP, what is the button state when pressed?

Answer: LOW.

11. What value range does analogRead(A0) return for the potentiometer?

Answer: 0–1023.

12. In the line lcd.print(potValue);, what happens?

Answer: Prints the current potentiometer value.

13. Why does the code use lcd.print(" "); before printing the potentiometer value?

Answer: To overwrite old characters with spaces.

14. What happens if the LCD’s I2C address is wrong (e.g., 0x20 vs 0x27)?

Answer: The LCD will not respond.

15. What is the delay of delay(200) used for in the loop?

Answer: To stabilize readings and reduce flickering.

16. The cursor coordinates (c, r) in lcd.setCursor(c, r) start from:

Answer: (0,0).

17. Which function clears the LCD completely?

Answer: lcd.clear().

18. What is the advantage of I2C over parallel LCD wiring?

Answer: Uses fewer Arduino pins.

19. If you want to display the text "Arduino Rocks!" on the second row, first column, what command should you use?

Answer: lcd.setCursor(1,2); lcd.print("Arduino Rocks!");

20. In the example code, what does the LCD show when the button is pressed?

Answer: "1"