displayio – Native helpers for driving displays

The displayio module contains classes to manage display output including synchronizing with refresh rates and partial updating.

displayio.release_displays() → None

Releases any actively used displays so their busses and pins can be used again. This will also release the builtin display on boards that have one. You will need to reinitialize it yourself afterwards. This may take seconds to complete if an active EPaperDisplay is refreshing.

Use this once in your code.py if you initialize a display. Place it right before the initialization so the display is active as long as possible.

class displayio.Bitmap(width: int, height: int, value_count: int)

Stores values of a certain size in a 2D array

Create a Bitmap object with the given fixed size. Each pixel stores a value that is used to index into a corresponding palette. This enables differently colored sprites to share the underlying Bitmap. value_count is used to minimize the memory used to store the Bitmap.

Parameters

  • width (int) – The number of values wide

  • height (int) – The number of values high

  • value_count (int) – The number of possible pixel values.

width :int

Width of the bitmap. (read only)

height :int

Height of the bitmap. (read only)

__getitem__(self, index: Union[Tuple[int, int], int]) → int

Returns the value at the given index. The index can either be an x,y tuple or an int equal to y * width + x.

This allows you to:

print(bitmap[0,1])
__setitem__(self, index: Union[Tuple[int, int], int], value: int) → None

Sets the value at the given index. The index can either be an x,y tuple or an int equal to y * width + x.

This allows you to:

bitmap[0,1] = 3
fill(self, value: int) → None

Fills the bitmap with the supplied palette index value.

class displayio.ColorConverter(*, dither: bool = False)

Converts one color format to another.

Create a ColorConverter object to convert color formats. Only supports RGB888 to RGB565 currently. :param bool dither: Adds random noise to dither the output image

dither :bool

When true the color converter dithers the output by adding random noise when truncating to display bitdepth

convert(self, color: int) → int

Converts the given RGB888 color to RGB565

displayio._DisplayBus

FourWire, ParallelBus or I2CDisplay

class displayio.Display(display_bus: _DisplayBus, init_sequence: ReadableBuffer, *, width: int = None, height: int = None, colstart: int = 0, rowstart: int = 0, rotation: int = 0, color_depth: int = 16, grayscale: bool = False, pixels_in_byte_share_row: bool = True, bytes_per_cell: int = 1, reverse_pixels_in_byte: bool = False, set_column_command: int = 42, set_row_command: int = 43, write_ram_command: int = 44, set_vertical_scroll: int = 0, backlight_pin: Optional[microcontroller.Pin] = None, brightness_command: Optional[int] = None, brightness: float = 1.0, auto_brightness: bool = False, single_byte_bounds: bool = False, data_as_commands: bool = False, auto_refresh: bool = True, native_frames_per_second: int = 60)

Manage updating a display over a display bus

This initializes a display and connects it into CircuitPython. Unlike other objects in CircuitPython, Display objects live until displayio.release_displays() is called. This is done so that CircuitPython can use the display itself.

Most people should not use this class directly. Use a specific display driver instead that will contain the initialization sequence at minimum.

Create a Display object on the given display bus (FourWire, ParallelBus or I2CDisplay).

The init_sequence is bitpacked to minimize the ram impact. Every command begins with a command byte followed by a byte to determine the parameter count and if a delay is need after. When the top bit of the second byte is 1, the next byte will be the delay time in milliseconds. The remaining 7 bits are the parameter count excluding any delay byte. The third through final bytes are the remaining command parameters. The next byte will begin a new command definition. Here is a portion of ILI9341 init code:

init_sequence = (b"\xe1\x0f\x00\x0E\x14\x03\x11\x07\x31\xC1\x48\x08\x0F\x0C\x31\x36\x0F" # Set Gamma
                 b"\x11\x80\x78"# Exit Sleep then delay 0x78 (120ms)
                 b"\x29\x80\x78"# Display on then delay 0x78 (120ms)
                )
 display = displayio.Display(display_bus, init_sequence, width=320, height=240)

The first command is 0xe1 with 15 (0xf) parameters following. The second and third are 0x11 and 0x29 respectively with delays (0x80) of 120ms (0x78) and no parameters. Multiple byte literals (b””) are merged together on load. The parens are needed to allow byte literals on subsequent lines.

The initialization sequence should always leave the display memory access inline with the scan of the display to minimize tearing artifacts.

Parameters

  • display_bus – The bus that the display is connected to

  • init_sequence (ReadableBuffer) – Byte-packed initialization sequence.

  • width (int) – Width in pixels

  • height (int) – Height in pixels

  • colstart (int) – The index if the first visible column

  • rowstart (int) – The index if the first visible row

  • rotation (int) – The rotation of the display in degrees clockwise. Must be in 90 degree increments (0, 90, 180, 270)

  • color_depth (int) – The number of bits of color per pixel transmitted. (Some displays support 18 bit but 16 is easier to transmit. The last bit is extrapolated.)

  • grayscale (bool) – True if the display only shows a single color.

  • pixels_in_byte_share_row (bool) – True when pixels are less than a byte and a byte includes pixels from the same row of the display. When False, pixels share a column.

  • bytes_per_cell (int) – Number of bytes per addressable memory location when color_depth < 8. When greater than one, bytes share a row or column according to pixels_in_byte_share_row.

  • reverse_pixels_in_byte (bool) – Reverses the pixel order within each byte when color_depth < 8. Does not apply across multiple bytes even if there is more than one byte per cell (bytes_per_cell.)

  • reverse_bytes_in_word (bool) – Reverses the order of bytes within a word when color_depth == 16

  • set_column_command (int) – Command used to set the start and end columns to update

  • set_row_command (int) – Command used so set the start and end rows to update

  • write_ram_command (int) – Command used to write pixels values into the update region. Ignored if data_as_commands is set.

  • set_vertical_scroll (int) – Command used to set the first row to show

  • backlight_pin (microcontroller.Pin) – Pin connected to the display’s backlight

  • brightness_command (int) – Command to set display brightness. Usually available in OLED controllers.

  • brightness (float) – Initial display brightness. This value is ignored if auto_brightness is True.

  • auto_brightness (bool) – If True, brightness is controlled via an ambient light sensor or other mechanism.

  • single_byte_bounds (bool) – Display column and row commands use single bytes

  • data_as_commands (bool) – Treat all init and boundary data as SPI commands. Certain displays require this.

  • auto_refresh (bool) – Automatically refresh the screen

  • native_frames_per_second (int) – Number of display refreshes per second that occur with the given init_sequence.

  • backlight_on_high (bool) – If True, pulling the backlight pin high turns the backlight on.

auto_refresh :bool

True when the display is refreshed automatically.

brightness :float

The brightness of the display as a float. 0.0 is off and 1.0 is full brightness. When auto_brightness is True, the value of brightness will change automatically. If brightness is set, auto_brightness will be disabled and will be set to False.

auto_brightness :bool

True when the display brightness is adjusted automatically, based on an ambient light sensor or other method. Note that some displays may have this set to True by default, but not actually implement automatic brightness adjustment. auto_brightness is set to False if brightness is set manually.

width :int

Gets the width of the board

height :int

Gets the height of the board

rotation :int

The rotation of the display as an int in degrees.

bus :_DisplayBus

The bus being used by the display

show(self, group: Group) → None

Switches to displaying the given group of layers. When group is None, the default CircuitPython terminal will be shown.

Parameters

group (Group) – The group to show.

refresh(self, *, target_frames_per_second: int = 60, minimum_frames_per_second: int = 1) → bool

When auto refresh is off, waits for the target frame rate and then refreshes the display, returning True. If the call has taken too long since the last refresh call for the given target frame rate, then the refresh returns False immediately without updating the screen to hopefully help getting caught up.

If the time since the last successful refresh is below the minimum frame rate, then an exception will be raised. Set minimum_frames_per_second to 0 to disable.

When auto refresh is on, updates the display immediately. (The display will also update without calls to this.)

Parameters

  • target_frames_per_second (int) – How many times a second refresh should be called and the screen updated.

  • minimum_frames_per_second (int) – The minimum number of times the screen should be updated per second.

fill_row(self, y: int, buffer: WriteableBuffer) → WriteableBuffer

Extract the pixels from a single row

Parameters

  • y (int) – The top edge of the area

  • buffer (WriteableBuffer) – The buffer in which to place the pixel data

class displayio.EPaperDisplay(display_bus: _DisplayBus, start_sequence: ReadableBuffer, stop_sequence: ReadableBuffer, *, width: int = None, height: int = None, ram_width: int = None, ram_height: int = None, colstart: int = 0, rowstart: int = 0, rotation: int = 0, set_column_window_command: Optional[int] = None, set_row_window_command: Optional[int] = None, single_byte_bounds: bool = False, write_black_ram_command: int = None, black_bits_inverted: bool = False, write_color_ram_command: Optional[int] = None, color_bits_inverted: bool = False, highlight_color: int = 0, refresh_display_command: int = None, refresh_time: float = 40, busy_pin: Optional[microcontroller.Pin] = None, busy_state: bool = True, seconds_per_frame: float = 180, always_toggle_chip_select: bool = False)

Manage updating an epaper display over a display bus

This initializes an epaper display and connects it into CircuitPython. Unlike other objects in CircuitPython, EPaperDisplay objects live until displayio.release_displays() is called. This is done so that CircuitPython can use the display itself.

Most people should not use this class directly. Use a specific display driver instead that will contain the startup and shutdown sequences at minimum.

Create a EPaperDisplay object on the given display bus (displayio.FourWire or displayio.ParallelBus).

The start_sequence and stop_sequence are bitpacked to minimize the ram impact. Every command begins with a command byte followed by a byte to determine the parameter count and if a delay is need after. When the top bit of the second byte is 1, the next byte will be the delay time in milliseconds. The remaining 7 bits are the parameter count excluding any delay byte. The third through final bytes are the remaining command parameters. The next byte will begin a new command definition.

Parameters

  • display_bus – The bus that the display is connected to

  • start_sequence (ReadableBuffer) – Byte-packed initialization sequence.

  • stop_sequence (ReadableBuffer) – Byte-packed initialization sequence.

  • width (int) – Width in pixels

  • height (int) – Height in pixels

  • ram_width (int) – RAM width in pixels

  • ram_height (int) – RAM height in pixels

  • colstart (int) – The index if the first visible column

  • rowstart (int) – The index if the first visible row

  • rotation (int) – The rotation of the display in degrees clockwise. Must be in 90 degree increments (0, 90, 180, 270)

  • set_column_window_command (int) – Command used to set the start and end columns to update

  • set_row_window_command (int) – Command used so set the start and end rows to update

  • set_current_column_command (int) – Command used to set the current column location

  • set_current_row_command (int) – Command used to set the current row location

  • write_black_ram_command (int) – Command used to write pixels values into the update region

  • black_bits_inverted (bool) – True if 0 bits are used to show black pixels. Otherwise, 1 means to show black.

  • write_color_ram_command (int) – Command used to write pixels values into the update region

  • color_bits_inverted (bool) – True if 0 bits are used to show the color. Otherwise, 1 means to show color.

  • highlight_color (int) – RGB888 of source color to highlight with third ePaper color.

  • refresh_display_command (int) – Command used to start a display refresh

  • refresh_time (float) – Time it takes to refresh the display before the stop_sequence should be sent. Ignored when busy_pin is provided.

  • busy_pin (microcontroller.Pin) – Pin used to signify the display is busy

  • busy_state (bool) – State of the busy pin when the display is busy

  • seconds_per_frame (float) – Minimum number of seconds between screen refreshes

  • always_toggle_chip_select (bool) – When True, chip select is toggled every byte

time_to_refresh :float

Time, in fractional seconds, until the ePaper display can be refreshed.

width :int

Gets the width of the display in pixels

height :int

Gets the height of the display in pixels

bus :_DisplayBus

The bus being used by the display

show(self, group: Group) → None

Switches to displaying the given group of layers. When group is None, the default CircuitPython terminal will be shown.

Parameters

group (Group) – The group to show.

refresh(self) → None

Refreshes the display immediately or raises an exception if too soon. Use time.sleep(display.time_to_refresh) to sleep until a refresh can occur.

class displayio.FourWire(spi_bus: busio.SPI, *, command: microcontroller.Pin = None, chip_select: microcontroller.Pin = None, reset: Optional[microcontroller.Pin] = None, baudrate: int = 24000000, polarity: int = 0, phase: int = 0)

Manage updating a display over SPI four wire protocol in the background while Python code runs. It doesn’t handle display initialization.

Create a FourWire object associated with the given pins.

The SPI bus and pins are then in use by the display until displayio.release_displays() is called even after a reload. (It does this so CircuitPython can use the display after your code is done.) So, the first time you initialize a display bus in code.py you should call :py:func`displayio.release_displays` first, otherwise it will error after the first code.py run.

Parameters

  • spi_bus (busio.SPI) – The SPI bus that make up the clock and data lines

  • command (microcontroller.Pin) – Data or command pin

  • chip_select (microcontroller.Pin) – Chip select pin

  • reset (microcontroller.Pin) – Reset pin. When None only software reset can be used

  • baudrate (int) – Maximum baudrate in Hz for the display on the bus

  • polarity (int) – the base state of the clock line (0 or 1)

  • phase (int) – the edge of the clock that data is captured. First (0) or second (1). Rising or falling depends on clock polarity.

reset(self) → None

Performs a hardware reset via the reset pin. Raises an exception if called when no reset pin is available.

send(self, command: int, data: FourWire, *, toggle_every_byte: bool = False) → None

Sends the given command value followed by the full set of data. Display state, such as vertical scroll, set via send may or may not be reset once the code is done.

class displayio.Group(*, max_size: int = 4, scale: int = 1, x: int = 0, y: int = 0)

Manage a group of sprites and groups and how they are inter-related.

Create a Group of a given size and scale. Scale is in one dimension. For example, scale=2 leads to a layer’s pixel being 2x2 pixels when in the group.

Parameters

  • max_size (int) – The maximum group size.

  • scale (int) – Scale of layer pixels in one dimension.

  • x (int) – Initial x position within the parent.

  • y (int) – Initial y position within the parent.

hidden :bool

True when the Group and all of it’s layers are not visible. When False, the Group’s layers are visible if they haven’t been hidden.

scale :int

Scales each pixel within the Group in both directions. For example, when scale=2 each pixel will be represented by 2x2 pixels.

x :int

X position of the Group in the parent.

y :int

Y position of the Group in the parent.

append(self, layer: Union[vectorio.VectorShape, Group, TileGrid]) → None

Append a layer to the group. It will be drawn above other layers.

insert(self, index: int, layer: Union[vectorio.VectorShape, Group, TileGrid]) → None

Insert a layer into the group.

index(self, layer: Union[vectorio.VectorShape, Group, TileGrid]) → int

Returns the index of the first copy of layer. Raises ValueError if not found.

pop(self, i: int = - 1) → Union[vectorio.VectorShape, Group, TileGrid]

Remove the ith item and return it.

remove(self, layer: Union[vectorio.VectorShape, Group, TileGrid]) → None

Remove the first copy of layer. Raises ValueError if it is not present.

__bool__(self) → bool
__len__(self) → int

Returns the number of layers in a Group

__getitem__(self, index: int) → Union[vectorio.VectorShape, Group, TileGrid]

Returns the value at the given index.

This allows you to:

print(group[0])
__setitem__(self, index: int, value: Union[vectorio.VectorShape, Group, TileGrid]) → None

Sets the value at the given index.

This allows you to:

group[0] = sprite
__delitem__(self, index: int) → None

Deletes the value at the given index.

This allows you to:

del group[0]
class displayio.I2CDisplay(i2c_bus: busio.I2C, *, device_address: int = None, reset: Optional[microcontroller.Pin] = None)

Manage updating a display over I2C in the background while Python code runs. It doesn’t handle display initialization.

Create a I2CDisplay object associated with the given I2C bus and reset pin.

The I2C bus and pins are then in use by the display until displayio.release_displays() is called even after a reload. (It does this so CircuitPython can use the display after your code is done.) So, the first time you initialize a display bus in code.py you should call :py:func`displayio.release_displays` first, otherwise it will error after the first code.py run.

Parameters

  • i2c_bus (busio.I2C) – The I2C bus that make up the clock and data lines

  • device_address (int) – The I2C address of the device

  • reset (microcontroller.Pin) – Reset pin. When None only software reset can be used

reset(self) → None

Performs a hardware reset via the reset pin. Raises an exception if called when no reset pin is available.

send(self, command: int, data: ReadableBuffer) → None

Sends the given command value followed by the full set of data. Display state, such as vertical scroll, set via send may or may not be reset once the code is done.

class displayio.OnDiskBitmap(file: typing.BinaryIO)

Loads values straight from disk. This minimizes memory use but can lead to much slower pixel load times. These load times may result in frame tearing where only part of the image is visible.

It’s easiest to use on a board with a built in display such as the Hallowing M0 Express.

import board
import displayio
import time
import pulseio

board.DISPLAY.auto_brightness = False
board.DISPLAY.brightness = 0
splash = displayio.Group()
board.DISPLAY.show(splash)

with open("/sample.bmp", "rb") as f:
    odb = displayio.OnDiskBitmap(f)
    face = displayio.TileGrid(odb, pixel_shader=displayio.ColorConverter())
    splash.append(face)
    # Wait for the image to load.
    board.DISPLAY.refresh(target_frames_per_second=60)

    # Fade up the backlight
    for i in range(100):
        board.DISPLAY.brightness = 0.01 * i
        time.sleep(0.05)

    # Wait forever
    while True:
        pass

Create an OnDiskBitmap object with the given file.

Parameters

file (file) – The open bitmap file

width :int

Width of the bitmap. (read only)

height :int

Height of the bitmap. (read only)

class displayio.Palette(color_count: int)

Map a pixel palette_index to a full color. Colors are transformed to the display’s format internally to save memory.

Create a Palette object to store a set number of colors.

Parameters

color_count (int) – The number of colors in the Palette

__bool__(self) → bool
__len__(self) → int

Returns the number of colors in a Palette

__getitem__(self, index: int) → Optional[int]

Return the pixel color at the given index as an integer.

__setitem__(self, index: int, value: Union[int, ReadableBuffer, Tuple[int, int, int]]) → None

Sets the pixel color at the given index. The index should be an integer in the range 0 to color_count-1.

The value argument represents a color, and can be from 0x000000 to 0xFFFFFF (to represent an RGB value). Value can be an int, bytes (3 bytes (RGB) or 4 bytes (RGB + pad byte)), bytearray, or a tuple or list of 3 integers.

This allows you to:

palette[0] = 0xFFFFFF                     # set using an integer
palette[1] = b'\xff\xff\x00'              # set using 3 bytes
palette[2] = b'\xff\xff\x00\x00'          # set using 4 bytes
palette[3] = bytearray(b'\x00\x00\xFF')   # set using a bytearay of 3 or 4 bytes
palette[4] = (10, 20, 30)                 # set using a tuple of 3 integers
make_transparent(self, palette_index: int) → None
make_opaque(self, palette_index: int) → None
class displayio.ParallelBus(*, data0: microcontroller.Pin = None, command: microcontroller.Pin = None, chip_select: microcontroller.Pin = None, write: microcontroller.Pin = None, read: microcontroller.Pin = None, reset: microcontroller.Pin = None)

Manage updating a display over 8-bit parallel bus in the background while Python code runs. This protocol may be refered to as 8080-I Series Parallel Interface in datasheets. It doesn’t handle display initialization.

Create a ParallelBus object associated with the given pins. The bus is inferred from data0 by implying the next 7 additional pins on a given GPIO port.

The parallel bus and pins are then in use by the display until displayio.release_displays() is called even after a reload. (It does this so CircuitPython can use the display after your code is done.) So, the first time you initialize a display bus in code.py you should call :py:func`displayio.release_displays` first, otherwise it will error after the first code.py run.

Parameters
reset(self) → None

Performs a hardware reset via the reset pin. Raises an exception if called when no reset pin is available.

send(self, command: int, data: ReadableBuffer) → None

Sends the given command value followed by the full set of data. Display state, such as vertical scroll, set via send may or may not be reset once the code is done.

class displayio.Shape(width: int, height: int, *, mirror_x: bool = False, mirror_y: bool = False)

Represents a shape made by defining boundaries that may be mirrored.

Create a Shape object with the given fixed size. Each pixel is one bit and is stored by the column boundaries of the shape on each row. Each row’s boundary defaults to the full row.

Parameters

  • width (int) – The number of pixels wide

  • height (int) – The number of pixels high

  • mirror_x (bool) – When true the left boundary is mirrored to the right.

  • mirror_y (bool) – When true the top boundary is mirrored to the bottom.

set_boundary(self, y: int, start_x: int, end_x: int) → None

Loads pre-packed data into the given row.

class displayio.TileGrid(bitmap: Bitmap, *, pixel_shader: Union[ColorConverter, Palette] = None, width: int = 1, height: int = 1, tile_width: Optional[int] = None, tile_height: Optional[int] = None, default_tile: int = 0, x: int = 0, y: int = 0)

A grid of tiles sourced out of one bitmap

Position a grid of tiles sourced from a bitmap and pixel_shader combination. Multiple grids can share bitmaps and pixel shaders.

A single tile grid is also known as a Sprite.

Create a TileGrid object. The bitmap is source for 2d pixels. The pixel_shader is used to convert the value and its location to a display native pixel color. This may be a simple color palette lookup, a gradient, a pattern or a color transformer.

tile_width and tile_height match the height of the bitmap by default.

Parameters

  • bitmap (Bitmap) – The bitmap storing one or more tiles.

  • or Palette pixel_shader (ColorConverter) – The pixel shader that produces colors from values

  • width (int) – Width of the grid in tiles.

  • height (int) – Height of the grid in tiles.

  • tile_width (int) – Width of a single tile in pixels. Defaults to the full Bitmap and must evenly divide into the Bitmap’s dimensions.

  • tile_height (int) – Height of a single tile in pixels. Defaults to the full Bitmap and must evenly divide into the Bitmap’s dimensions.

  • default_tile (int) – Default tile index to show.

  • x (int) – Initial x position of the left edge within the parent.

  • y (int) – Initial y position of the top edge within the parent.

hidden :bool

True when the TileGrid is hidden. This may be False even when a part of a hidden Group.

x :int

X position of the left edge in the parent.

y :int

Y position of the top edge in the parent.

flip_x :bool

If true, the left edge rendered will be the right edge of the right-most tile.

flip_y :bool

If true, the top edge rendered will be the bottom edge of the bottom-most tile.

transpose_xy :bool

If true, the TileGrid’s axis will be swapped. When combined with mirroring, any 90 degree rotation can be achieved along with the corresponding mirrored version.

pixel_shader :Union[ColorConverter, Palette]

The pixel shader of the tilegrid.

__getitem__(self, index: Union[Tuple[int, int], int]) → int

Returns the tile index at the given index. The index can either be an x,y tuple or an int equal to y * width + x.

This allows you to:

print(grid[0])
__setitem__(self, index: Union[Tuple[int, int], int], value: int) → None

Sets the tile index at the given index. The index can either be an x,y tuple or an int equal to y * width + x.

This allows you to:

grid[0] = 10

or:

grid[0,0] = 10