3.2 Display Module API Manual

Attention

This module has significant changes starting from firmware version V0.7. If you are using firmware prior to V0.7, please refer to the old version of the documentation.

1. Overview

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

To add a custom screen, refer to Display Debugger.

2. API Introduction

2.1 init

Description

Initializes the Display path, including the VO module, DSI module, and LCD/HDMI. Must be called before MediaManager.init()

Syntax

init(type=None, width=None, height=None, osd_num=1, to_ide=False, fps=None, quality=90)

Parameters

Parameter Name	Description	Input / Output	Notes
type	Display device type	Input	Required
width	Resolution width	Input	Default value depends on type
height	Resolution height	Input	Default value depends on type
osd_num	Number of layers supported in show_image	Input	Larger values occupy more memory
to_ide	Whether to transfer screen display to IDE display	Input	Occupies more memory when enabled
fps	Display frame rate	Input	Only supports VIRT type
quality	Sets Jpeg compression quality	Input	Effective only when to_ide=True, range [10-100]

Return Value

Return Value	Description
None

2.2 show_image

Description

Displays an image on the screen.

Syntax

show_image(img, x=0, y=0, layer=None, alpha=255, flag=0)

Parameters

Parameter Name	Description	Input / Output	Notes
img	Image to display	Input
x	X value of the starting coordinate	Input
y	Y value of the starting coordinate	Input
layer	Display on the specified layer	Input	Only supports OSD layer. For multiple layers, set osd_num in init
alpha	Layer blending alpha	Input
flag	Display flag	Input

Return Value

Return Value	Description
None

2.3 deinit

Description

Performs deinitialization. The deinit method will shut down the entire Display path, including the VO module, DSI module, and LCD/HDMI. Must be called before MediaManager.deinit()
Must be called after sensor.stop()

Syntax

deinit()

Return Value

Return Value	Description
None

2.4 bind_layer

Description

Binds the output of the sensor or vdec module to the screen display. This allows continuous image display without manual intervention. Must be called before init

Syntax

bind_layer(src=(mod, dev, layer), dstlayer, rect=(x, y, w, h), pix_format, alpha, flag)

Parameters

Parameter Name	Description	Input / Output	Notes
src	Output information of sensor or vdec	Input	Obtainable via sensor.bind_info()
dstlayer	Display layer to bind to display layer	Input	Can be bound to video or osd layer
rect	Display area	Input	Obtainable via sensor.bind_info()
pix_format	Image pixel format	Input	Obtainable via sensor.bind_info()
alpha	Layer blending alpha	Input
flag	Display flag	Input	LAYER_VIDEO1 not supported

Return Value

Return Value	Description
None

2.5 width

Description

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

Syntax

width(layer=None)

Parameters

Parameter Name	Description	Input / Output	Notes
layer	Specifies the display layer to query. If None, returns the screen resolution width.	Input	Optional

Return Value

Return Value	Description
width	Width of the screen or specified layer

2.6 height

Description

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

Syntax

height(layer=None)

Parameters

Parameter Name	Description	Input / Output	Notes
layer	Specifies the display layer to query. If None, returns the screen resolution height.	Input	Optional

Return Value

Return Value	Description
height	Height of the screen or specified layer

3. Data Structure Description

3.1 type

Type	Example Initialization Parameters	Notes
VIRT	Display.init(Display.VIRT, width=640, height=480)	Default: 640x480@90 For IDE debugging only. Does not display on external screens. Custom resolutions (64x64)-(4096x4096) and frame rates (1-200) supported.
DEBUGGER		For debugging screens.
ST7701	Display.init(Display.ST7701, width=800, height=480)	Default: 800x480
	Display.init(Display.ST7701, width=480, height=800)	Portrait mode: 480x800
	Display.init(Display.ST7701, width=854, height=480)	854x480
	Display.init(Display.ST7701, width=480, height=854)	Portrait mode: 480x854
	Display.init(Display.ST7701, width=640, height=480)	640x480
	Display.init(Display.ST7701, width=480, height=640)	Portrait mode: 480x640
	Display.init(Display.ST7701, width=368, height=552)	368x552
	Display.init(Display.ST7701, width=552, height=368)	Portrait mode: 552x368
HX8399	Display.init(Display.HX8399, width=1920, height=1080)	Default: 1920x1080
	Display.init(Display.HX8399, width=1080, height=1920)	Portrait mode: 1080x1920
ILI9806	Display.init(Display.ILI9806, width=800, height=480)	Default: 800x480
	Display.init(Display.ILI9806, width=480, height=800)	Portrait mode: 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

3.2 layer

K230 supports 2 video layers and 4 OSD layers:

Display Layer	Description	Notes
LAYER_VIDEO1		Only usable in bind_layer, supports hardware rotation
LAYER_VIDEO2		Only usable in bind_layer, no hardware rotation support
LAYER_OSD0		Usable in show_image and bind_layer
LAYER_OSD1		Usable in show_image and bind_layer
LAYER_OSD2		Usable in show_image and bind_layer
LAYER_OSD3		Usable in show_image and bind_layer

3.3 flag

Flag	Description	Notes
FLAG_ROTATION_0	Rotate 0°
FLAG_ROTATION_90	Rotate 90°
FLAG_ROTATION_180	Rotate 180°
FLAG_ROTATION_270	Rotate 270°
FLAG_MIRROR_NONE	No mirroring
FLAG_MIRROR_HOR	Horizontal mirroring
FLAG_MIRROR_VER	Vertical mirroring
FLAG_MIRROR_BOTH	Horizontal & vertical mirroring

4. Sample Program

from media.display import *  # Import the display module to use display related interfaces
from media.media import *    # Import the media module to use media related interfaces
import os, time, image       # Import the image module to use image related interfaces

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

# Create an 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()