tv — tv shield driver

The tv module is used for controlling the tv shield.

Example usage:

import sensor, tv

# Setup camera.
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.SIF)
sensor.skip_frames()
tv.init()

# Show image.
while(True):
    tv.display(sensor.snapshot())

Functions

tv.init

tv.init(type=TV_SHIELD, triple_buffer=False) -> None

Initializes an attached tv output module.

type indicates how the lcd module should be initialized:

tv.TV_NONE: Do nothing.
tv.TV_SHIELD: Initialize a TV output module. Uses pins P0, P1, P2, and P3.

triple_buffer If True then makes updates to the screen non-blocking in tv.TV_SHIELD mode at the cost of 3X the display RAM (495 KB).

tv.deinit

tv.deinit() -> None

Deinitializes the tv module, internal/external hardware, and I/O pins.

tv.width

tv.width() -> int

Returns 352 pixels. This is the sensor.SIF resolution.

tv.height

tv.height() -> int

Returns 240 pixels. This is the sensor.SIF resolution.

tv.type

tv.type() -> int

Returns the type of the screen that was set during tv.init().

tv.triple_buffer

tv.triple_buffer() -> bool

Returns if triple buffering is enabled that was set during tv.init().

tv.channel

tv.channel(channel: int | None = None) -> int

For the wireless TV shield this sets the broadcast channel between 1-8. If passed without a channel argument then this method returns the previously set channel (1-8). Default is channel 8.

tv.display

tv.display(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.

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).

Constants

tv.TV_NONE

tv.TV_NONE: int

Returned by tv.type() when the this module is not initialized.

tv.TV_SHIELD

tv.TV_SHIELD: int

Used to initialize the TV module.