Screen

Introduction

The Screen blocks control the V5 Brain’s touchscreen, allowing your robot to show text, numbers, and graphics, and respond to touch input.

By default, the font for printing to the Brain is monospaced small which has 12 rows and 48 columns.

For drawing, the Brain’s resolution is 480 x 240 pixels.

Below is a list of available blocks:

Cursor Print – Display text and manage the print cursor.

• print on screen – Prints text, numbers, or variable values on the Brain screen.

• set cursor to row column on screen – Moves the cursor to a specific row and column.

• set cursor to next row on screen – Moves the cursor to column 1 of the next row.

• clear row on screen – Clears a specified row of text.

• screen cursor column – Reports the column number where text will be printed.

• screen cursor row – Reports the row number where text will be printed.

Settings – Change the appearance of text and graphics.

• clear screen – Erases all text and drawings from the screen.

• set font on screen – Changes the font type and size for text display.

• set print precision on screen – Sets how many decimal places to show when printing numbers.

• set pen width on screen – Sets the thickness of drawn lines and shape outlines.

• set pen / font color on screen – Sets the color of text, pixels, lines, and shape outlines.

• set fill color on screen – Sets the fill color for drawn shapes.

Draw – Create shapes, lines, and graphics on the Brain screen.

• draw pixel on screen – Draws a single pixel at a coordinate.

• draw line on screen – Draws a line between two points.

• draw rectangle on screen – Draws a rectangle using two corner points.

• draw circle on screen – Draws a circle with a defined center and radius.

Touch – Detect touch input on the Brain’s screen.

• screen pressed – Reports whether the screen is currently being touched.

• screen position – Reports the selected x or y coordinate of the last screen press.

• when screen – Runs attached blocks when the screen is pressed or released.

Cursor Print

print on screen

The print on screen stack block prints text, numbers, or variable values on the Brain screen at the current cursor position and font.

Display text on the Brain screen

  when started
  print [VEXcode] on screen ▶

Parameters	Description
value	The text, number, or variable value to display on the screen.
and set cursor to next row	Select the arrow ( ▶ ) to expand the block to say and set cursor to next row, so the cursor moves to column 1 of the next row after printing.

Example

When started, displays the message ‘Hello, Robot!’ at the starting cursor position on the screen.

    when started
    [Display a message at the starting cursor position.]
    print [Hello, Robot!] on screen ▶

set cursor to row column on screen

The set cursor to row column on screen stack block moves the cursor to a specific row and column on the Brain screen. The next print on screen block will start printing at that location. How many rows and columns can comfortably fit depends on the selected font. With the default monospaced medium font, up to 8 rows and 13 columns can be displayed clearly. Text placed beyond this range may be cut off or become difficult to read.

Monospaced fonts have characters that are all the same width, making text placement consistent. In contrast, proportional fonts vary in character width, so some letters take up more space than others. However, regardless of which type is used, the set cursor to row column on screen stack block positions the cursor based on row and column size, not font style. The font size can be adjusted using the set font on screen stack block.

Set cursor stack block

    set cursor to row [1] column [1] on screen

Parameters	Description
row	The row to move the cursor to.
column	The column to move the cursor to.

Example

When started, moves the cursor to row 3, column 2 on the screen and prints ‘Row 3, Column 2’.

    when started
    [Display text starting at Row 3 Column 12.]
    set cursor to row [3] column [12] on screen
    print [Row 3, Column 12] on screen ▶

set cursor to next row on screen

The set cursor to next row on screen stack block moves the cursor to column 1 on the next row on the Brain screen.

set cursor to next row stack block

    set cursor to next row on screen

Parameters	Description
	This block has no parameters.

Example

When started, prints ‘Line 1’ on the screen, moves the cursor to the next row, and then prints ‘Line 2’.

    when started
    [Display two lines of text.]
    print [Line 1] on screen ▶
    set cursor to next row on screen
    print [Line 2] on screen ▶

clear row on screen

The clear row on screen stack block clears a single row of text on the Brain screen.

Clear row stack block

    clear row [1] on screen

Parameters	Description
row	The row number to clear.

Example

When started, prints text on two rows. The first row remains, while the second row disappears after 3 seconds.

    when started
    [Only keep the text on row 1.]
    print [This text stays] on screen ▶
    set cursor to next row on screen
    print [This text disappears] on screen ▶
    wait [3] seconds
    clear row [2] on screen

screen cursor column

The screen cursor column reporter block reports the column number where text will be printed as an integer.

screen cursor column reporter block

    (screen cursor column)

Parameters	Description
	This block has no parameters.

Example

When started, moves the cursor to row 3, column 2 on the screen and prints the current cursor column number.

    when started
    [Display the cursor's current column.]
    set cursor to row [3] column [15] on screen
    print (screen cursor column) on screen ▶

screen cursor row

The screen cursor row reporter block reports the row number where text will be printed as an integer.

screen cursor row reporter block

    (screen cursor row)

Parameters	Description
	This block has no parameters.

Example

When started, moves the cursor to row 6, column 2 on the screen and prints the current cursor row number.

    when started
    [Display the cursor's current row.]
    set cursor to row [3] column [2] on screen
    print (screen cursor row) on screen ▶

Settings

clear screen

The clear screen stack block clears all drawings and text from the Brain screen.

clear screen stack block

    clear screen

Parameters	Description
	This block has no parameters.

Example

When started, draws a circle with center (120,120) and radius 40 pixels. After 2 seconds, the screen is cleared.

    when started
    [Draw a circle, and clear it after 2 seconds.]
    draw circle [120] [120] [40] on screen
    wait [2] seconds
    clear screen

set font on screen

The set font on screen stack block sets the font and size used for displaying text on the Brain screen. This font will apply to all subsequently printed text.

set font stack block

    set font to [monospaced v] [medium v] on screen

Parameters	Description
style	The font style: monospaced or proportional
size	The font size (examples below): extra small small medium large extra large super large Note: Extra small and small sizes are not available for proportional fonts.

monospaced extra small	monospaced small	monospaced medium
monospaced large	monospaced extra large	monospaced super large
proportional medium	proportional large	proportional extra large
proportional super large

Example

When started, sets the font to ‘monospaced extra large’ and prints ‘VEX’ on the screen.

    when started
    [Display text using a larger font]
    set font to [monospaced v] [extra large v] on screen
    print [VEX] on screen ▶

set print precision on screen

The set print precision on screen stack block sets how many decimal places to show when printing numbers on the Brain screen. This print precision will apply to all subsequently printed numbers.

set print precision stack block

    set print precision to [0.1 v] on screen

Parameters	Description
precision	The print precision to use: 1 0.1 0.01 0.001 All Digits

Example

When started, sets print precision to two decimal places and prints 1/3 as 0.33 on the screen.

    when started
    [Print 1/3 as 0.33.]
    set print precision to [0.01 v] on screen
    print ([1] [math_division v] [3]) on screen ▶

set pen width on screen

The set pen width on screen stack block sets the thickness of drawn lines and shape outlines.

set pen width stack block

    set pen width to [10] on screen

Parameters	Description
width	The pen width, in pixels, from 0 to 32.

Example

When started, sets the pen width to 10 pixels and draws a rectangle with the top-left corner at (50,50), width 130 pixels, and height 60 pixels.

    when started
    [Draw a rectangle with a pen width of 10.]
    set pen width to [10] on screen
    draw rectangle [50] [50] [130] [60] on screen

set pen / font color on screen

The set pen / font color on screen stack block sets the color of text, pixels, lines, and shape outlines.

set pen / font color stack block

    set pen / font color to [red v] on screen

Parameters	Description
color	The pen and font color to use: red green blue black white yellow orange purple cyan transparent

Example

When started, sets the pen color to orange and draws a rectangle with the top-left corner at (50, 50), width 130 pixels, and height 60 pixels.

    when started
    [Draw a rectangle with orange borders.]
    set pen / font color to [orange v] on screen
    draw rectangle [50] [50] [130] [60] on screen

set fill color on screen

The set fill color on screen stack block sets the fill color used when shapes are drawn.

set fill color stack block

    set fill color to [red v] on screen

Parameters	Description
color	The fill color to use: red green blue black white yellow orange purple cyan transparent

Examples

When started, sets the fill color to purple and draws a rectangle. It is at (50, 130) with a width of 100 pixels and a height of 60 pixels.

    when started
    [Draw a purple rectangle.]
    set fill color to [purple v] on screen
    draw rectangle [50] [130] [100] [60] on screen

Draw

draw pixel on screen

The draw pixel on screen stack block draws one pixel at the selected x and y coordinate using the current pen color.

draw pixel stack block

    draw pixel [0] [0] on screen

Parameters	Description
x	The x-coordinate to draw the pixel from 0 to 479.
y	The y-coordinate to draw the pixel from 0 to 239.

Example

When started, draws four pixels that mark the corners of a small square.

    when started
    [Draw the pixels marking the corners of a square.]
    draw pixel [250] [100] on screen
    draw pixel [275] [100] on screen
    draw pixel [250] [125] on screen
    draw pixel [275] [125] on screen

draw line on screen

The draw line on screen stack block draws a line from the first screen coordinate (x1, y1) to the second screen coordinate (x2, y2) using the current pen width and pen color.

draw line stack block

    draw line [0] [0] [10] [10] on screen

Parameters	Description
x1	The x-coordinate in pixels of the start of the line from 0 to 479.
y1	The y-coordinate in pixels of the start of the line from 0 to 239.
x2	The x-coordinate in pixels of the end of the line from 0 to 479.
y2	The y-coordinate in pixels of the end of the line from 0 to 239.

Example

When started, draws a diagonal line from the top-left corner (0, 0) to the bottom-right corner (479, 239) of the screen.

    when started
    [Draw a line from the top left to bottom right of the screen.]
    draw line [0] [0] [479] [239] on screen

draw rectangle on screen

The draw rectangle on screen stack block draws a rectangle using the current pen width, pen color, and fill color.

draw rectangle stack block

    draw rectangle [0] [0] [10] [10] on screen

Parameters	Description
x	The x-coordinate in pixels of the top-left corner of the rectangle from 0 to 479.
y	The y-coordinate in pixels of the top-left corner of the rectangle from 0 to 239.
width	The width of the rectangle in pixels.
height	The height of the rectangle in pixels.

Example

When started, draws a rectangle on the screen with the top-left corner at (50,50), width of 130 pixels, and height of 60 pixels.

    when started
    [Draw a rectangle on the screen.]
    draw rectangle [50] [50] [130] [60] on screen

draw circle on screen

The draw circle on screen stack block draws a circle using the current pen width, pen color, and fill color.

draw circle stack block

    draw circle [0] [0] [10] on screen

Parameters	Description
x	The x-coordinate in pixels of the center of the circle from 0 to 479.
y	The y-coordinate in pixels of the center of the circle from 0 to 239.
radius	The radius of the circle in pixels.

Example

When started, draws a circle on the screen with the center at (120, 120) and a radius of 40 pixels.

    when started
    [Draw a circle on the screen.]
    draw circle [120] [120] [40] on screen

Touch

screen pressed

The screen pressed Boolean block reports whether the Brain’s touchscreen is currently being pressed.

• True – The screen is being pressed.

• False – The screen is not being pressed.

screen pressed Boolean block

    <screen pressed?>

Parameters	Description
	This block has no parameters.

When started, changes the screen color after the screen is pressed.

    when started
    [Change the screen's color after it's pressed.]
    wait until <screen pressed?>
    set fill color to [green v] on screen
    draw rectangle [0] [0] [479] [239] on screen

When the screen is pressed, the first message is shown. The code then waits until the screen is released, and only continues after the screen is pressed again to show the second message.

    when started
    [Display different messages after the screen is pressed.]
    wait until <screen pressed?>
    print [First message!] on screen ▶
    set cursor to next row on screen
    [Lift finger to press the screen again.]
    wait until <not <screen pressed?>>
    wait until <screen pressed?>
    print [Second message!] on screen ▶

screen position

The screen position reporter block reports the selected coordinate of the last screen press. The x-coordinate is from 0 (left) to 479 (right). The y-coordinate is from 0 (top) to 239 (bottom).

screen position reporter block

    (screen [x v] position)

Parameters	Description
axis	The coordinate of the last screen press to report: x – The horizontal position or y – The vertical position

When the Brain screen is pressed, draws a circle at the press location.

    when started
    [Display a circle where the screen is pressed.]
    wait until <screen pressed?>
    set fill color to [white v] on screen
    draw circle (screen [x v] position) (screen [y v] position) [20] on screen

when screen

The when screen hat block runs the attached stack of blocks when the Brain screen is pressed or released.

when screen hat block

    when Brain screen [pressed v] :: hat events

Parameters	Description
state	When to run the attached stack of blocks: pressed runs when the screen is pressed, and released runs when the screen is released.

When the Brain screen is pressed, draws a circle at the press location.

    when Brain screen [pressed v] :: hat events
    [Color the screen with polka dots by pressing it repeatedly.]
    set fill color to [red v] on screen
    draw circle (screen [x v] position) (screen [y v] position) [20] on screen