ST7701S Display Driver¶

Models¶

This display driver supports displays with 16 bit parallel interfaces, often referred to as “RGB”. It currently supports the ST7701S chip.

This driver has been tested with the following displays:

Seeed Sensecap Indicator

Makerfabs 4” display

Usage¶

This component requires an ESP32 (usually an ESP32-S3 because of the number of GPIO pins required) and the use of ESP-IDF. PSRAM is a requirement due to the size of the display buffer.

../../_images/indicator.jpg — Sensecap Indicator display¶

# Example minimal configuration entry
display:
  - platform: st7701s
    dimensions:
      width: 480
      height: 480
    cs_pin: REPLACE_ME
    reset_pin: REPLACE_ME
    de_pin: REPLACE_ME
    hsync_pin: REPLACE_ME
    vsync_pin: REPLACE_ME
    pclk_pin: REPLACE_ME
    # Replace XX with the correct pin number

    data_pins:
      red:
        - XX        #r1
        - XX        #r2
        - XX        #r3
        - XX        #r4
        - XX        #r5
      green:
        - XX        #g0
        - XX        #g1
        - XX        #g2
        - XX        #g3
        - XX        #g4
        - XX        #g5
      blue:
        - XX        #b1
        - XX        #b2
        - XX        #b3
        - XX        #b4
        - XX        #b5

Configuration variables:¶

init_sequence (Optional, A list of byte arrays): Specifies the init sequence for the display
data_pins (Required): A list of pins used for the databus. Specified in 3 groups.
- red: (Required, Pin Schema) Exactly 5 pin numbers for the red databits, listed from least to most significant bit.
- green: (Required, Pin Schema) Exactly 6 pin numbers for the green databits, listed from least to most significant bit.
- blue: (Required, Pin Schema) Exactly 5 pin numbers for the blue databits, listed from least to most significant bit.
de_pin (Required, Pin Schema): The DE pin.
dc_pin (Optional, Pin Schema): The DC pin.
pclk_pin (Required, Pin Schema): The PCLK pin.
hsync_pin (Required, Pin Schema): The Horizontal sync pin.
vsync_pin (Required, Pin Schema): The Vertical sync pin.
reset_pin (Optional, Pin Schema): The RESET pin.
hsync_pulse_width (Optional, int): The horizontal sync pulse width.
hsync_front_porch (Optional, int): The horizontal front porch length.
hsync_back_porch (Optional, int): The horizontal back porch length.
vsync_pulse_width (Optional, int): The vertical sync pulse width.
vsync_front_porch (Optional, int): The vertical front porch length.
vsync_back_porch (Optional, int): The vertical back porch length.
pclk_frequency (Optional): Set the pixel clock speed. Default is 8MHz.
pclk_inverted (Optional bool): If the pclk is active negative (default is True)
update_interval (Optional, Time): The interval to re-draw the screen. Defaults to 5s.
auto_clear_enabled (Optional, boolean): Whether to automatically clear the display in each loop (‘’true’’, default), or to keep the existing display content (must overwrite explicitly, e.g., only on data change).
pages (Optional, list): Show pages instead of a single lambda. See Display Pages.
id (Optional, ID): Manually specify the ID used for code generation.
color_order (Optional): Should be one of bgr (default) or rgb.
dimensions (Required): Dimensions of the screen, specified either as width x height (e.g 320x240) or with separate config keys.
- height (Required, int): Specifies height of display in pixels.
- width (Required, int): Specifies width of display.
- offset_width (Optional, int): Specify an offset for the x-direction of the display, typically used when an LCD is smaller than the maximum supported by the driver chip. Default is 0
- offset_height (Optional, int): Specify an offset for the y-direction of the display. Default is 0.
data_rate (Optional): Set the data rate of the SPI interface to the display. One of 80MHz, 40MHz,
20MHz, 10MHz, 5MHz, 2MHz, 1MHz (default), 200kHz, 75kHz or 1kHz.
spi_mode (Optional): Set the mode for the SPI interface to the display. Default is MODE0 but some displays require MODE3.
invert_colors (Optional): With this boolean option you can invert the display colors. Note some of the displays have this option set automatically to true and can’t be changed.
rotation (Optional): Rotate the display presentation in software. Choose one of 0°, 90°, 180°, or 270°. This option cannot be used with transform.
transform (Optional): Transform the display presentation using hardware. All defaults are false. This option cannot be used with rotation.
- swap_xy (Optional, boolean): If true, exchange the x and y axes.
- mirror_x (Optional, boolean): If true, mirror the x axis.
- mirror_y (Optional, boolean): If true, mirror the y axis.
lambda (Optional, lambda): The lambda to use for rendering the content on the display. See Display Rendering Engine for more information.

Note: To rotate the display in hardware use one of the following combinations:

90 degrees - use swap_xy with mirror_x

180 degrees - use mirror_x with mirror_y

270 degrees - use swap_xy with mirror_y

The horizontal and vertical pulse_width, front_porch and back_porch values are optional, but may require changing for a specific display. Refer to the manufacturer’s sample code for suitable values. These specify timing requirements for the display.

The init_sequence requires a list of elements, one of which may be a single integer selecting a canned init sequence (the default and currently the only sequence is 1), the remainder must be byte arrays providing additional init commands, each consisting of a command byte followed by zero or more data bytes.

These will be collected and sent to the display via SPI during initialisation.

Example configurations¶

Seeed Sensecap Indicator¶

display:
  - platform: st7701s
    auto_clear_enabled: false
    update_interval: never
    spi_mode: MODE3
    color_order: RGB
    dimensions:
      width: 480
      height: 480
    invert_colors: true
    transform:
      mirror_x: true
      mirror_y: true
    cs_pin:
      pca9554: p_c_a
      number: 4
    reset_pin:
      pca9554: p_c_a
      number: 5
    de_pin: 18
    hsync_pin: 16
    vsync_pin: 17
    pclk_pin: 21
    init_sequence:
      - 1 # select canned init sequence number 1
      - [ 0xE0, 0x1F ]  # Set sunlight readable enhancement
    data_pins:
      red:
        - 4         #r1
        - 3         #r2
        - 2         #r3
        - 1         #r4
        - 0         #r5
      green:
        - 10        #g0
        - 9         #g1
        - 8         #g2
        - 7         #g3
        - 6         #g4
        - 5         #g5
      blue:
        - 15        #b1
        - 14        #b2
        - 13        #b3
        - 12        #b4
        - 11        #b5
    lambda: |-
      it.fill(COLOR_BLACK);
      it.print(0, 0, id(my_font), id(my_red), TextAlign::TOP_LEFT, "Hello World!");

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