class SPIDisplay – SPI Display Driver

The SPIDisplay class is used for driving SPI LCDs.

Example usage for driving the 128x160 LCD shield:

import sensor, display

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

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

Constructors

display.SPIDisplay

class display.SPIDisplay(width=128, height=160, refresh=60, bgr=False, byte_swap=False, triple_buffer, controller, backlight)

width SPI LCD width. By default this is 128 to match the OpenMV 128x160 LCD shield.

height SPI LCD height. By default this is 160 to match the OpenMV 128x160 LCD shield.

refresh Sets the LCD refresh rate in hertz. This controls the SPI LCD shield clock.

bgr set to True to swap the red and blue channels. This argument allows you to use our driver with more types of displays.

byte_swap set to True to swap RGB565 pixel bytes sent to the LCD. This argument allows you to use our driver with more types of displays.

triple_buffer If True then makes updates to the screen non-blocking at the cost of 3X the display size in RAM. This is on by default for OpenMV Cam boards with SDRAM.

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

SPIDisplay.deinit

SPIDisplay.deinit() -> None

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

SPIDisplay.width

SPIDisplay.width() -> int

Returns the width of the screen.

SPIDisplay.height

SPIDisplay.height() -> int

Returns the height of the screen.

SPIDisplay.refresh

SPIDisplay.refresh() -> int

Returns the refresh rate.

SPIDisplay.bgr

SPIDisplay.bgr() -> bool

Returns if the red and blue channels are swapped.

SPIDisplay.byte_swap

SPIDisplay.byte_swap() -> bool

Returns if the RGB565 pixels are displayed byte reversed.

SPIDisplay.triple_buffer

SPIDisplay.triple_buffer() -> bool

Returns if triple buffering is enabled.

SPIDisplay.write

SPIDisplay.write(image: image.Image, x=0, y=0, x_scale=1.0, y_scale=1.0, roi: Tuple[int, int, int, int] | None = None, rgb_channel=-1, alpha=256, color_palette=None, alpha_palette=None, hint=0)

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).

SPIDisplay.clear

SPIDisplay.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.

SPIDisplay.backlight

SPIDisplay.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.

SPIDisplay.bus_write

SPIDisplay.bus_write(cmd: int, args=None) -> None

Send the SPI Display cmd with args.