class RGBDisplay – RGB Display Driver

The RGBDisplay class is used for driving 24-bit parallel LCDs.

Example usage for driving the 800x480 24-bit Parallel LCD:

import sensor, display

# Setup camera.
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.LCD)
sensor.skip_frames()
lcd = display.RGBDisplay()

# Show image.
while(True):
    lcd.write(sensor.snapshot())

Constructors

class display.RGBDisplay(framesize=FWVGA, refresh=60, display_on=True, portrait=False, controller, backlight)

framesize One of the standard supported resolutions.

refresh Sets the screen refresh rate in hertz. This controls the RGB LCD clock.

display_on Enables the display. Pass False here when the 24-bit parallel LCD output is shared by multiple devices like the TFP410 chip for driving HDMI displays to keep the display off while driving the databus still.

portrait Swap the framesize width and height.

controller Pass the controller chip class here to initialize it along with the display.

backlight specify a backlight controller module to use. By default the backlight will be controlled via a GPIO pin.

Methods

RGBDisplay.deinit() → None

Releases the I/O pins and RAM used by the class. This is called automatically on destruction.

RGBDisplay.width() → int

Returns the width of the screen.

RGBDisplay.height() → int

Returns the height of the screen.

RGBDisplay.refresh() → int

Returns the refresh rate.

RGBDisplay.write(image: image.Image, x=0, y=0, x_scale=1.0, y_scale=1.0, roi=None, rgb_channel=-1, alpha=256, color_palette=None, alpha_palette=None, hint=0) → None

Displays an image whose top-left corner starts at location x, y.

You may also pass a path instead of an image object for this method to automatically load the image from disk and draw it in one step. E.g. write("test.jpg").

x_scale controls how much the displayed image is scaled by in the x direction (float). If this value is negative the image will be flipped horizontally. Note that if y_scale is not specified then it will match x_scale to maintain the aspect ratio.

y_scale controls how much the displayed image is scaled by in the y direction (float). If this value is negative the image will be flipped vertically. Note that if x_scale is not specified then it will match x_scale to maintain the aspect ratio.

roi is the region-of-interest rectangle tuple (x, y, w, h) of the image to display. This allows you to extract just the pixels in the ROI to scale.

rgb_channel is the RGB channel (0=R, G=1, B=2) to extract from an RGB565 image (if passed) and to render on the display. For example, if you pass rgb_channel=1 this will extract the green channel of the RGB565 image and display that in grayscale.

alpha controls how opaque the image is. A value of 256 displays an opaque image while a value lower than 256 produces a black transparent image. 0 results in a perfectly black image.

color_palette if not -1 can be image.PALETTE_RAINBOW, image.PALETTE_IRONBOW, or a 256 pixel in total RGB565 image to use as a color lookup table on the grayscale value of whatever the input image is. This is applied after rgb_channel extraction if used.

alpha_palette if not -1 can be a 256 pixel in total GRAYSCALE image to use as a alpha palette which modulates the alpha value of the input image being displayed at a pixel pixel level allowing you to precisely control the alpha value of pixels based on their grayscale value. A pixel value of 255 in the alpha lookup table is opaque which anything less than 255 becomes more transparent until 0. This is applied after rgb_channel extraction if used.

hint can be a logical OR of the flags:

• image.AREA: Use area scaling when downscaling versus the default of nearest neighbor.

• image.BILINEAR: Use bilinear scaling versus the default of nearest neighbor scaling.

• image.BICUBIC: Use bicubic scaling versus the default of nearest neighbor scaling.

• image.CENTER: Center the image being drawn on the display. This is applied after scaling.

• image.HMIRROR: Horizontally mirror the image.

• image.VFLIP: Vertically flip the image.

• image.TRANSPOSE: Transpose the image (swap x/y).

• image.EXTRACT_RGB_CHANNEL_FIRST: Do rgb_channel extraction before scaling.

• image.APPLY_COLOR_PALETTE_FIRST: Apply color palette before scaling.

• image.SCALE_ASPECT_KEEP: Scale the image being drawn to fit inside the display.

• image.SCALE_ASPECT_EXPAND: Scale the image being drawn to fill the display (results in cropping)

• image.SCALE_ASPECT_IGNORE: Scale the image being drawn to fill the display (results in stretching).

• image.ROTATE_90: Rotate the image by 90 degrees (this is just VFLIP | TRANSPOSE).

• image.ROTATE_180: Rotate the image by 180 degrees (this is just HMIRROR | VFLIP).

• image.ROTATE_270: Rotate the image by 270 degrees (this is just HMIRROR | TRANSPOSE).

RGBDisplay.clear(display_off=False) → None

Clears the lcd screen to black.

display_off if True instead turns off the display logic versus clearing the frame LCD frame buffer to black. You should also turn off the backlight too after this to ensure the screen goes to black as many displays are white when only the backlight is on.

RGBDisplay.backlight(value: int | None = None) → int

Sets the lcd backlight dimming value. 0 (off) to 100 (on).

Note that unless you pass DACBacklight or PWMBacklight the backlight will be controlled as a GPIO pin and will only go from 0 (off) to !0 (on).

Pass no arguments to get the state of the backlight value.