`Display` Module API Manual#

Attention

This module has undergone significant changes since firmware version V0.7. If you are using firmware prior to V0.7, please refer to the older version documentation.

Overview#

This manual is intended to guide developers in using the Micro Python API to call the CanMV Display module to achieve image display functionality.

To add a custom screen, please refer to RTOS SDK / How to Add Panel

API Introduction#

init#

Description

Initializes the Display path, including the VO module, DSI module, and LCD/HDMI.

Syntax

init(type, width=0, height=0, fps=0, flag=0, osd_num=1, to_ide=False, quality=90)

Parameters

Parameter Name	Description	Input / Output	Notes
type	Display device type	Input	Required
width	Resolution width	Input	Optional parameter, default value is determined by `type`
height	Resolution height	Input	Optional parameter, default value is determined by `type`
fps	Display frame rate	Input	Only some display device types support specifying frame rate
flag	Display flag	Input
osd_num	Number of OSD layers supported when show_image is called	Input	The larger the value, the more memory it occupies, default is 1
to_ide	Whether to transmit the screen display to the IDE	Input	Enabling this uses more memory, implemented via WBC functionality
quality	Sets JPEG compression quality	Input	Only effective when `to_ide=True`, range [10-100], default 90

Return Value

Return Value	Description
None

deinit#

Description

Performs deinitialization. The deinit method will close the entire Display path, including the VO module, DSI module, and LCD/HDMI.

Syntax

deinit()

Return Value

Return Value	Description
None

inited#

Description

Queries whether the Display module has been initialized.

Syntax

inited()

Return Value

Return Value	Description
bool	`True` indicates initialized, `False` indicates not initialized

config_layer#

Description

Configures the properties of a display layer. This method is usually called before binding a layer to set the display parameters of the layer.

Syntax

config_layer(rect, pix_format, layer, alpha=255, flag=0)

Parameters

Parameter Name	Description	Input / Output	Notes
rect	Display area (x, y, w, h)	Input	Required, in tuple form
pix_format	Image pixel format	Input	See pix_format
layer	Display layer ID	Input	Required, specifies the layer to configure
alpha	Layer blending transparency	Input	Range 0-255, default 255 (opaque)
flag	Display flag	Input	Default 0

Return Value

Return Value	Description
int	Configured layer ID

bind_layer#

Description

Binds the output of the sensor or vdec module to the screen display. Continuously displays images without user manual intervention.

Syntax

bind_layer(src, rect, pix_format, layer, alpha=255, flag=0)

Parameters

Parameter Name	Description	Input / Output	Notes
src	Source channel information (mod, dev, chn)	Input	Can be obtained via `sensor.bind_info()`, in tuple format
rect	Display area (x, y, w, h)	Input	Can be obtained via `sensor.bind_info()`
pix_format	Image pixel format	Input	Can be obtained via `sensor.bind_info()`
layer	Display layer bound to Display	Input	Can be bound to `video` or `osd` layer
alpha	Layer blending transparency	Input	Range 0-255, default 255
flag	Display flag	Input	Default 0

Return Value

Return Value	Description
None

unbind_layer#

Description

Unbinds the binding relationship of the specified layer.

Syntax

unbind_layer(layer)

Parameters

Parameter Name	Description	Input / Output	Notes
layer	Display layer ID	Input	Required

Return Value

Return Value	Description
bool	`True` indicates successful unbinding, `False` indicates failure

disable_layer#

Description

Disables the specified display layer.

Syntax

disable_layer(layer)

Parameters

Parameter Name	Description	Input / Output	Notes
layer	Display layer ID	Input	Required

Return Value

Return Value	Description
None

show_image#

Description

Displays an image on the screen.

Syntax

show_image(img, x=0, y=0, layer=Display.LAYER_OSD0, alpha=None, pixel_format=None, flag=0)

Parameters

Parameter Name	Description	Input / Output	Notes
img	Image object to be displayed	Input	Required
x	x value of the starting coordinate	Input	Default 0
y	y value of the starting coordinate	Input	Default 0
layer	Display to the specified layer	Input	Only supports OSD layer, default `LAYER_OSD0`
alpha	Layer blending transparency	Input	Range 0-255, `None` means using the layer’s original setting
pixel_format	Image pixel format	Input	`None` means using the image’s original format, see pix_format
flag	Display flag	Input	Default 0

Return Value

Return Value	Description
None

width#

Description

Gets the display width of the screen or a specific layer.

Syntax

width(layer=None)

Parameters

Parameter Name	Description	Input / Output	Notes
layer	Specifies the width of the display layer to obtain	Input	Optional, if not provided, means obtaining the resolution width of the screen

Return Value

Return Value	Description
width	Width information of the screen or display layer, in pixels

height#

Description

Gets the display height of the screen or a specific layer.

Syntax

height(layer=None)

Parameters

Parameter Name	Description	Input / Output	Notes
layer	Specifies the height of the display layer to obtain	Input	Optional, if not provided, means obtaining the resolution height of the screen

Return Value

Return Value	Description
height	Height information of the screen or display layer, in pixels

fps#

Description

Gets the current display frame rate.

Syntax

fps()

Return Value

Return Value	Description
int	Current display frame rate, in fps

writeback#

Description

Queries or sets the WriteBack (WBC) feature status. The WBC feature is used to send back the screen display content, typically for transmission to the IDE display.

Syntax

writeback(enable=None)

Parameters

Parameter Name	Description	Input / Output	Notes
enable	Sets the WBC feature status	Input	Optional, `True` means enabled, `False` means disabled. If no parameter is passed, it queries the current status

Return Value

Return Value	Description
bool	Returns the current WBC status when querying; returns the operation result when setting

writeback_dump#

Description

Captures a frame of display content from WBC. Requires to_ide=True to be set during init and the WBC feature to be enabled.

Syntax

writeback_dump(timeout=1000)

Parameters

Parameter Name	Description	Input / Output	Notes
timeout	Timeout duration (milliseconds)	Input	Default 1000ms

Return Value

Return Value	Description
object	Returns an object containing video frame information

Data Structure Description#

type#

Type	Parameter Value	Notes
VIRT	640x480@90	Default `IDE` debugging only, does not display content on external screen Users can customize resolution (64x64)-(4096x4096) and frame rate (1-200)
DEBUGGER		Dedicated debugging screen
ST7701	Display.init(Display.ST7701, width = 800, height = 480)	Default 800x480
	Display.init(Display.ST7701, width = 480, height = 800)	480x800
	Display.init(Display.ST7701, width = 854, height = 480)	854x480
	Display.init(Display.ST7701, width = 480, height = 854)	480x854
	Display.init(Display.ST7701, width = 640, height = 480)	640x480
	Display.init(Display.ST7701, width = 480, height = 640)	480x640
	Display.init(Display.ST7701, width = 368, height = 544)	368x544
	Display.init(Display.ST7701, width = 544, height = 368)	544x368
HX8399	Display.init(Display.HX8399, width = 1920, height = 1080)	Default 1920x1080
	Display.init(Display.HX8399, width = 1080, height = 1920)	1920x1080
ILI9806	Display.init(Display.ILI9806, width = 800, height = 480)	Default 800x480
	Display.init(Display.ILI9806, width = 480, height = 800)	480x800
LT9611	Display.init(Display.LT9611, width = 1920, height = 1080, fps = 30)	Default 1920x1080@30
	Display.init(Display.LT9611, width = 1920, height = 1080, fps = 60)	1920x1080@60
	Display.init(Display.LT9611, width = 1280, height = 720, fps = 60)	1280x720@60
	Display.init(Display.LT9611, width = 1280, height = 720, fps = 50)	1280x720@50
	Display.init(Display.LT9611, width = 1280, height = 720, fps = 30)	1280x720@30
	Display.init(Display.LT9611, width = 640, height = 480, fps = 60)	640x480@60
ILI9881	Display.init(Display.ILI9881, width = 1280, height = 800)	Default 1280x800
	Display.init(Display.ILI9881, width = 800, height = 1280)	800x1280
NT35516	Display.init(Display.NT35516, width=960, height=536)	Default 960x536
	Display.init(Display.NT35516, width=536, height=960)	536x960
NT35532	Display.init(Display.NT35532, width=1920, height=1080)	Default 1920x1080
	Display.init(Display.NT35532, width=1080, height=1920)	1080x1920
GC9503	Display.init(Display.GC9503, width=800, height=480)	Default 800x480
	Display.init(Display.GC9503, width=480, height=800)	480x800
ST7102	Display.init(Display.ST7102, width=640, height=480)	Default 640x480
	Display.init(Display.ST7102, width=480, height=640)	480x640
AML020T	Display.init(Display.AML020T, width=480, height=360)	Default 480x360
	Display.init(Display.AML020T, width=360, height=480)	360x480
JD9852	Display.init(Display.JD9852, width=320, height=240)	Default 320x240
	Display.init(Display.JD9852, width=240, height=320)	240x320
ST7789	Display.init(Display.ST7789, width=320, height=240)	Default 320x240
	Display.init(Display.ST7789, width=240, height=320)	240x320

layer#

K230 provides 3 video layers and 4 OSD layers. They are classified as follows:

Display Layer	Constant Name	Description	Supported Format
Video Layer 1	`Display.LAYER_VIDEO1`	Recommended for displaying video data	Only supports `YUV420SP`
Video Layer 2	`Display.LAYER_VIDEO2`	Recommended for displaying video data	Only supports `YUV420SP`
Video Layer 3	`Display.LAYER_VIDEO3`	Recommended for displaying video data	Only supports `YUV420SP`
OSD Layer 0	`Display.LAYER_OSD0`	Graphics overlay layer	Only supports RGB color space
OSD Layer 1	`Display.LAYER_OSD1`	Graphics overlay layer	Only supports RGB color space
OSD Layer 2	`Display.LAYER_OSD2`	Graphics overlay layer	Only supports RGB color space
OSD Layer 3	`Display.LAYER_OSD3`	Graphics overlay layer	Only supports RGB color space

flag#

Flag	Constant Name	Description
No Rotation	`Display.FLAG_ROTATION_NONE` or `0`	No rotation
Rotate 0 degrees	`Display.FLAG_ROTATION_0`	Rotate 0 degrees
Rotate 90 degrees	`Display.FLAG_ROTATION_90`	Rotate 90 degrees
Rotate 180 degrees	`Display.FLAG_ROTATION_180`	Rotate 180 degrees
Rotate 270 degrees	`Display.FLAG_ROTATION_270`	Rotate 270 degrees
No Mirroring	`Display.FLAG_MIRROR_NONE` or `0`	No mirroring
Horizontal Mirroring	`Display.FLAG_MIRROR_HOR`	Horizontal mirroring
Vertical Mirroring	`Display.FLAG_MIRROR_VER`	Vertical mirroring
Horizontal and Vertical Mirroring	`Display.FLAG_MIRROR_BOTH`	Perform both horizontal and vertical mirroring simultaneously

pix_format#

Color Format	Constant Name	Description
Grayscale	`image.GRAYSCALE` or `PIXFORMAT_GRAYSCALE`	8-bit grayscale format, 1 byte per pixel
RGB565	`image.RGB565` or `PIXFORMAT_RGB565`	RGB format, 16 bits/pixel (5:6:5)
ARGB8888	`image.ARGB8888` or `PIXFORMAT_ARGB8888`	ARGB format, 32 bits/pixel (A:R:G:B)
ABGR8888	`image.ABGR8888` or `PIXFORMAT_ABGR8888`	ABGR format, 32 bits/pixel (A:B:G:R)
RGBA8888	`image.RGBA8888` or `PIXFORMAT_RGBA8888`	RGBA format, 32 bits/pixel (R:G:B:A)
BGRA8888	`image.BGRA8888` or `PIXFORMAT_BGRA8888`	BGRA format, 32 bits/pixel (B:G:R:A)
RGB888	`image.RGB888` or `PIXFORMAT_RGB888`	RGB format, 24 bits/pixel (R:G:B)
BGR888	`image.BGR888` or `PIXFORMAT_BGR888`	BGR format, 24 bits/pixel (B:G:R)

Notes#

Layer Support: show_image only supports OSD layers. If you need to use multiple OSD layers, please set the osd_num parameter during init.
Image Size: When calling show_image, the image size cannot exceed the screen resolution.
Rotation Handling: Certain screen types (such as ST7701’s 368x544 mode) have differences between hardware size and application size. The API automatically handles this conversion.
WBC Function: If you need to use writeback_dump to capture screen content, you must set to_ide=True during init.

Example Programs#

Basic Display Example#

from media.display import *
from media.media import *
import os, time, image

# Use LCD as display output
Display.init(Display.ST7701, width=800, height=480, to_ide=True)
# Initialize media manager
MediaManager.init()

# Create image for drawing
img = image.Image(800, 480, image.RGB565)
img.clear()
img.draw_string_advanced(0, 0, 32, "Hello World!，你好世界！！！", color=(255, 0, 0))

Display.show_image(img)

try:
    while True:
        time.sleep(1)
        os.exitpoint()
except KeyboardInterrupt as e:
    print("User stopped:", e)
except BaseException as e:
    print(f"Exception: {e}")

Display.deinit()
MediaManager.deinit()

Sensor Binding Example#

from media.display import *
from media.sensor import *
from media.media import *
import time

# Initialize sensor
sensor = Sensor()
sensor.reset()
sensor.set_framesize(width=800, height=480)
sensor.set_pixformat(Sensor.RGB565)

# Get sensor binding information
bind_info = sensor.bind_info()

# Configure and bind display layer
Display.config_layer(rect=(0, 0, 800, 480),
                     pix_format=bind_info[2],
                     layer=Display.LAYER_VIDEO1)
Display.bind_layer(src=bind_info[0],
                   rect=bind_info[1],
                   pix_format=bind_info[2],
                   layer=Display.LAYER_VIDEO1)

# Initialize display
Display.init(Display.ST7701, width=800, height=480)
MediaManager.init()

# Start sensor
sensor.run()

try:
    while True:
        time.sleep(1)
except KeyboardInterrupt:
    print("User stopped")
finally:
    sensor.stop()
    Display.deinit()
    MediaManager.deinit()

Display Module API Manual

Contents

`Display` Module API Manual#

Overview#

API Introduction#

init#

deinit#

inited#

config_layer#

bind_layer#

unbind_layer#

disable_layer#

show_image#

width#

height#

fps#

writeback#

writeback_dump#

Data Structure Description#

type#

layer#

flag#

pix_format#

Notes#

Example Programs#

Basic Display Example#

Sensor Binding Example#

Display Module API Manual

Contents

Display Module API Manual#

Overview#

API Introduction#

init#

deinit#

inited#

config_layer#

bind_layer#

unbind_layer#

disable_layer#

show_image#

width#

height#

fps#

writeback#

writeback_dump#

Data Structure Description#

type#

layer#

flag#

pix_format#

Notes#

Example Programs#

Basic Display Example#

Sensor Binding Example#

`Display` Module API Manual#