LCD cursor positioning in Arduino - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the cursor to the first column and first row on the LCD.

Arduino

lcd.setCursor([1], 0);

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

A0

B1

C2

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 0 for the first column.

Confusing row and column order.

The first column on the LCD is column 0, so we use 0 as the first argument in setCursor.

2fill in blank

medium

Complete the code to move the cursor to the third column on the second row.

Arduino

lcd.setCursor([1], 1);

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

A2

B3

C1

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using 3 instead of 2 for the third column.

Mixing up row and column numbers.

Columns are zero-indexed, so the first column is 0, the second is 1, and the third column is 2.

3fill in blank

hard

Fix the error in the code to correctly position the cursor at column 4, row 0.

Arduino

lcd.setCursor(4, [1]);

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

A2

B0

C1

D3

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 0 for the first row.

Confusing row and column arguments.

The first row is row 0, so the second argument to setCursor should be 0.

4fill in blank

hard

Fill both blanks to set the cursor to the last column on the last row of a 16x2 LCD.

Arduino

lcd.setCursor([1], [2]);

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

A15

B16

C1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Using 16 for the last column (out of range).

Using 2 for the last row (out of range).

For a 16x2 LCD, columns go from 0 to 15, so last column is 15. Rows go from 0 to 1, so last row is 1.

5fill in blank

hard

Fill all three blanks to set the cursor to column 0, row 1, and then print 'Hello'.

Arduino

lcd.setCursor([1], [2]);
lcd.print([3]);

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

A0

B1

C"Hello"

D"World"

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 for the column instead of 0.

Using 0 for the row instead of 1.

Forgetting quotes around the string.

Column 0 and row 1 set the cursor to the first column of the second row. Then printing "Hello" displays the text there.

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