LCD cursor positioning in Arduino - Mini Project: Build & Apply

LCD Cursor Positioning

📖 Scenario: You have a 16x2 LCD screen connected to an Arduino. You want to display messages at specific positions on the screen to make the output clear and organized.

🎯 Goal: Learn how to position the cursor on an LCD screen using Arduino code and display text at different locations.

📋 What You'll Learn

Use the LiquidCrystal library

Initialize the LCD with 16 columns and 2 rows

Use lcd.setCursor(col, row) to position the cursor

Display text at specified positions on the LCD

💡 Why This Matters

🌍 Real World

Positioning text on an LCD is useful for creating clear and readable displays on devices like home appliances, clocks, and measurement instruments.

💼 Career

Understanding LCD cursor positioning is important for embedded systems developers and electronics engineers working with user interfaces on hardware devices.

1

Set up the LCD object

Write code to include the LiquidCrystal library and create an lcd object with pins 12, 11, 5, 4, 3, and 2.

Arduino

// Include the LiquidCrystal library and create the lcd object
// Your code here

Hint

Use #include <LiquidCrystal.h> to include the library. Then create LiquidCrystal lcd(12, 11, 5, 4, 3, 2);.

2

Initialize the LCD in setup()

In the setup() function, initialize the LCD with 16 columns and 2 rows using lcd.begin(16, 2).

Arduino

#include 
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // Initialize the LCD with 16 columns and 2 rows
  // Your code here
}

void loop() {
}

Hint

Inside setup(), call lcd.begin(16, 2); to set up the LCD size.

3

Position the cursor and print text

In the setup() function, after initializing the LCD, use lcd.setCursor(0, 0) to move the cursor to the first column of the first row, then print "Hello, World!". Next, use lcd.setCursor(0, 1) to move to the first column of the second row and print "LCD Cursor Pos".

Arduino

#include 
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);
  // Set cursor to column 0, row 0 and print "Hello, World!"
  // Set cursor to column 0, row 1 and print "LCD Cursor Pos"
  // Your code here
}

void loop() {
}

Hint

Use lcd.setCursor(column, row) to move the cursor, then lcd.print() to show text.

4

Display the final output

Upload the code and observe the LCD screen. The first row should show Hello, World! and the second row should show LCD Cursor Pos. Write a Serial.println statement to print "LCD display updated" in the serial monitor.

Arduino

#include 
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Hello, World!");
  lcd.setCursor(0, 1);
  lcd.print("LCD Cursor Pos");
  // Initialize serial communication at 9600 baud
  // Print "LCD display updated" to the serial monitor
  // Your code here
}

void loop() {
}

Hint

Use Serial.begin(9600); in setup() to start serial communication, then Serial.println("LCD display updated"); to print the message.

Practice

1. What does the Arduino command lcd.setCursor(0, 1) do on a 16x2 LCD?

easy

A. Clears the LCD screen

B. Moves the cursor to the second column of the first row

C. Moves the cursor to the first column of the second row

D. Prints text at the current cursor position

Solution

1. Step 1: Understand lcd.setCursor parameters

   The first number is the column (starting at 0), the second is the row (starting at 0).

2. Step 2: Apply to given command

   lcd.setCursor(0, 1) moves the cursor to column 0 (first column) and row 1 (second row).

3. Final Answer:

   Moves the cursor to the first column of the second row -> Option C

4. Quick Check:

   Columns and rows start at zero = first column, second row [OK]

Hint: Remember columns and rows start at zero [OK]

Common Mistakes:

• Thinking rows start at 1 instead of 0
• Confusing column and row order
• Assuming setCursor prints text

2. Which of the following is the correct syntax to set the cursor to the third column and first row on an LCD?

easy

A. lcd.setCursor(3, 1);

B. lcd.setCursor(1, 2);

C. lcd.setCursor(0, 3);

D. lcd.setCursor(2, 0);

Solution

1. Step 1: Recall zero-based indexing

   Columns and rows start at 0, so third column is 2, first row is 0.

2. Step 2: Match parameters to correct syntax

   lcd.setCursor(2, 0) sets cursor to third column, first row.

3. Final Answer:

   lcd.setCursor(2, 0); -> Option D

4. Quick Check:

   Third column = 2, first row = 0 [OK]

Hint: Count columns and rows from zero [OK]

Common Mistakes:

• Using 1-based indexing for columns or rows
• Swapping column and row values
• Missing semicolon at end

3. What will be the output on a 16x2 LCD after running this code?

lcd.setCursor(5, 0);
lcd.print("Hi");
lcd.setCursor(0, 1);
lcd.print("Bye");

medium

A. First row: 'Hi' starting at first column, second row: 'Bye' starting at first column

B. First row: ' Hi' (5 spaces then Hi), second row: 'Bye' starting at first column

C. First row: 'Hi' starting at sixth column, second row: 'Bye' starting at sixth column

D. First row: ' Hi' (5 spaces then Hi), second row: ' Bye' (5 spaces then Bye)

Solution

1. Step 1: Analyze first setCursor and print

   lcd.setCursor(5, 0) moves cursor to column 5, row 0. Printing "Hi" starts at column 5 on first row.

2. Step 2: Analyze second setCursor and print

   lcd.setCursor(0, 1) moves cursor to first column, second row. Printing "Bye" starts there.

3. Final Answer:

   First row: ' Hi' (5 spaces then Hi), second row: 'Bye' starting at first column -> Option B

4. Quick Check:

   Cursor moves control print position [OK]

Hint: Cursor sets exact print start position [OK]

Common Mistakes:

• Assuming print always starts at first column
• Confusing row and column numbers
• Ignoring spaces before printed text

4. Identify the error in this Arduino code snippet for LCD cursor positioning:

lcd.setCursor(16, 0);
lcd.print("Hello");

medium

A. Column index 16 is out of range for a 16-column LCD

B. Row index 0 is invalid, should start at 1

C. Missing lcd.begin() before setCursor

D. lcd.print() cannot print strings

Solution

1. Step 1: Check column index range

   Columns start at 0, so valid columns are 0 to 15 for a 16-column LCD. 16 is out of range.

2. Step 2: Verify other parts

   Row 0 is valid (rows start at 0). lcd.print() can print strings. lcd.begin() is needed but not shown here, but question focuses on cursor.

3. Final Answer:

   Column index 16 is out of range for a 16-column LCD -> Option A

4. Quick Check:

   Column max index = 15 for 16 columns [OK]

Hint: Columns max at size minus one [OK]

Common Mistakes:

• Using 1-based indexing for columns
• Assuming lcd.print can't print strings
• Ignoring lcd.begin() requirement

5. You want to display a 4-letter word centered on the second row of a 20x4 LCD. Which lcd.setCursor() command correctly positions the cursor before printing?

hard

A. lcd.setCursor(8, 1);

B. lcd.setCursor(9, 1);

C. lcd.setCursor(7, 1);

D. lcd.setCursor(10, 1);

Solution

1. Step 1: Calculate center position for 4 letters on 20 columns

   Center column is 20 / 2 = 10. For 4 letters, start at 10 - (4 / 2) = 8.

2. Step 2: Set cursor to column 8 on second row

   Row 1 is second row (rows start at 0). So lcd.setCursor(8, 1) is correct.

3. Final Answer:

   lcd.setCursor(8, 1); -> Option A

4. Quick Check:

   Center start = half width minus half word length [OK]

Hint: Center = (width/2) - (word length/2) [OK]

Common Mistakes:

• Using 1-based indexing for rows or columns
• Starting cursor too far left or right
• Confusing row and column numbers