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GDISPLAY module

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Jaume Olivé Petrus edited this page Jul 19, 2017 · 42 revisions

About this

This module contains functions for accessing graphic displays, and gives the programmer an api to work with graphic displays in a unified form, regardless of the used display.

Supported chipsets

Chipset Variants Comments Identifier
ST7735 ST7735_18 Black tab, 1.8" gdisplay.ST7735_18
ST7735B_18 Blue tab, 1.8" gdisplay.ST7735B_18
ST7735G_18 Green tab, 1.8" gdisplay.ST7735G_18
ST7735G_144 Green tab, 1.44" gdisplay.ST7735G_144
ST7735_096 Green tab, 0.96" gdisplay.ST7735_096
PCD8544 --- Nokia 5110 gdisplay.PCD8544
ILI9341 --- --- gdisplay.ILI9341

When using a display with this module you must attach the display, using the gdisplay.attach function, using the right display identifier.

System fonts

Font Identifier Comments
Default gdisplay.FONT_DEFAULT
DejaVu 18 gdisplay.FONT_DEJAVU18
DejaVu 24 gdisplay.FONT_DEJAVU24
Ubuntu 16 gdisplay.FONT_UBUNTU16
Comic 24 gdisplay.FONT_COMIC24
Tooney 32 gdisplay.FONT_TOONEY32
Minya 24 gdisplay.FONT_MINYA24
7segments gdisplay.FONT_7SEG
LCD gdisplay.FONT_LCD Old style font, used in the past in smalls LCD, such as NOKIA 5110

Points

Colors

General purpose functions

gdisplay.attach(chipset, [orientation, framed])

Initialize the display and clear the screen.

Arguments:

  • chipset: chipset used by the display. Can be any identifier from the supported chipsets.
  • orientation (optional): display orientation, can be either gdisplay.LANDSCAPE, gdisplay.LANDSCAPE_FLIP, gdisplay.PORTRAIT, or gdisplay.PORTRAIT_FLIP. Default orientation is gdisplay.LANDSCAPE.
  • framed (optional): if true frame buffer is used. Default is false.

Returns: nothing, or an exception.

-- Attach an ILI9341 display with orientation LANDSCAPE_FLIP,
-- and without frame buffer
gdisplay.attach(gdisplay.ILI9341, gdisplay.LANDSCAPE_FLIP, false)

gdisplay.getscreensize()

Get current screen size (width & height) in pixels. Remember that for the same display, the screen size may vary depending on the screen's orientation.

Arguments: nothing.

Returns: the screen size, or an exception

  • xsize: width of the screen in pixels
  • ysize: height of the screen in pixels

gdisplay.clear([color])

Clear the display to specified color.

Arguments:

  • color (optional): the color used to fill de display. The default color depends on the display chipset, for example in TFT displays it is black, and in monochrome LCD displays it is white. In general, the default color is one that keeps all of the screen pixels off.

Returns: noting, or an exception.

-- Clear the display to RED
gdisplay.clear(gdisplay.RED)

-- Clear the display to RED
gdisplay.clear({255, 0, 0})

-- Clear the display to default color
gdisplay.clear()

gdisplay.off()

Turns the display off and preserve power. Back light has to be turned off separately.

Arguments: nothing Returns: nothing or an exception

gdisplay.on()

Turns the display on.

Arguments: nothing Returns: nothing or an exception

gdisplay.invert(invert)

Arguments:

  • invert: if true, show inverted colors, and if false, show normal colors. Returns: nothing or an exception

gdisplay.setorient(orientation)

Set the display orientation, and clear the screen to the default color. The default color depends on the display chipset, for example in TFT displays it is black, and in monochrome LCD displays it is white. In general, the default color is one that keeps all of the screen pixels off.

Arguments:

  • orientaion: display orientation, can be either gdisplay.LANDSCAPE, gdisplay.LANDSCAPE_FLIP, gdisplay.PORTRAIT, or gdisplay.PORTRAIT_FLIP.

Returns: nothing, or an exception.

-- Set the display orientation to LANDSCAPE_FLIP
gdisplay.setorient(gdisplay.LANDSCAPE_FLIP)

Clipping functions

gdisplay.setclipwin(point0, point1)

Sets the clipping area coordinates. All writing to the display is clipped to that area.

Arguments:

  • point0: top left point of the clipping area.
  • point1: bottom right point of the clipping area.

Returns: nothing, or an exception.

-- Set the clipping area to (10,10) - (50, 50)
gdisplay.setclipwin({10,10}, {50, 50})

-- Draw a pixel outside the clipping area. Pixel is not show
-- on the display.
gdisplay.putpixel({1,1})

-- Draw a pixel inside the clipping area. Pixel is show
-- on the display.
gdisplay.putpixel({20,20})

gdisplay.resetclipwin()

Reset the clipping area to full screen.

Arguments: nothing Returns: nothing, or an exception.

-- Reset the clipping area to full screen
gdisplay.resetclipwin()

-- Pixel now is show on the display.
gdisplay.putpixel({1,1})

Text functions

Text functions are used for write text.

gdisplay.setfont(font identifier | font name)

Set the font used when writing the text to display.

Arguments:

  • font identifier: the identifier of the system's font. Can be any identifier from the system fonts.
  • font name: if the programmer wants to use a custom font, the file name with the font definition.

Returns: nothing, or an exception.

-- Set the font to UBUNTU16_FONT
gdisplay.setfont(gdisplay.UBUNTU16_FONT)

gdisplay.getfontsize()

Get current font size in pixels. Useful if FONT_7SEG is used to get actual character width and height.

Arguments: nothing

Returns: the font size, or an exception

  • xsize: width of the font character in pixels. For the proportional fonts, maximal char width will be returned.
  • ysize: height of the font character in pixels.

gdisplay.getfontheight()

Get current font height in pixels.

Arguments: nothing

Returns: height of the font character in pixels, or an exception.

gdisplay.setrot(angle)

Set text rotation when writing text.

Arguments:

  • angle: rotation angle, in degrees (from 0 to 360)

Returns: nothing, or an exception.

gdisplay.settransp(transparency)

Set transparency when writing the text.

Arguments:

  • transparency: if true only text foreground color is shown, if false all the text background is filled with the background color.

Returns: nothing, or an exception.

gdisplay.setwrap(wrap)

Set line wrapping when writing the text. If wrap is true, text will be wrap to new line, otherwise it will be clipped.

Arguments:

  • wrap: if true wrapping is on.

Returns: nothing, or an exception.

gdisplay.setfixed(force)

Forces fixed width print when using proportional fonts.

Arguments:

  • force: if true force fixed. Returns: nothing, or an exception.

Drawing functions

gdisplay.putpixel(point, [color])

Draws pixel on display at the point coordinates using the current foreground color, or a given color.

Arguments:

  • point: the point coordinates where draw the pixel.
  • color (optional): the color to use for draw the pixel. If not specified foreground color is used.

Returns: nothing, or an exception.

-- Draw a pixel at point (50, 50), using current foreground
gdisplay.putpixel(50, 50)

-- Draw a pixel at point (50, 50), using current foreground
gdisplay.putpixel({50, 50})

-- Draw a pixel at point (50, 50), using RED color
gdisplay.putpixel({50, 50}, gdisplay.RED)

-- Draw a pixel at point (50, 50), using RED color
gdisplay.putpixel({50, 50}, {255, 0, 0})

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