Note

This is the documentation for the latest development branch and may refer to features that are not available in released versions. If you are looking for a specific release, use the drop-down menu on the left.

App Center

Introduction

The App Center is a LVGL-based graphical demo launcher located at CanMV/sdcard/examples/28-APP_CENTER on the development board. It integrates more than 30 AI and CV examples into a touch-interactive interface: after booting, you land on the home page with an icon grid; tap an icon to launch the corresponding example, and tap stop to return to the home page—no need to repeatedly open and switch scripts in the IDE.

For developers, the App Center is also a reference example for running multiple applications together, demonstrating how to perform application switching, resource cleanup, and display adaptation under limited memory.

Key features:

• Icon grid home page, displayed in pages, with touch-based selection.

• Chinese/English UI switching, with the language selection persistently saved to /sdcard/app_center_language.txt.

• Adaptive display: cards, footer, and status bar are laid out according to the actual display resolution, so screens of different sizes all display correctly.

• Runtime status bar: shows current frame rate, detection count, and Wi-Fi connection status.

• Model missing detection: checks whether the kmodel and resource files exist before launching the app, and gives a clear prompt instead of crashing directly.

• Strict resource cleanup: every app fully releases model and media resources when stopped, ensuring the next app can load properly.

How to Run

Open CanMV IDE K230, select File(F) -> Open File in the top-left corner, choose This PC->CanMV->sdcard->examples->28-APP_CENTER->main.py, and click the run button in the bottom-left corner of the IDE.

If you want the App Center to launch automatically at boot, copy main.py to the root of /sdcard (or refer to How to set a debugged script to auto-start).

Note

The App Center requires a touch screen for interaction. When using HDMI output without a touch device, the interface can be displayed but cannot be selected. The IDE’s virtual touch is also supported—you can click directly on the IDE screen.

Tip

The App Center loads fonts from /sdcard/examples/15-LVGL/data/font/ and icons from /sdcard/examples/utils/icons/. If these directories are missing, the interface will display abnormally—please make sure the image is complete.

Built-in App List

Category	Apps
Face	Face Detection, Face Registration, Face Recognition, Face Keypoints, Face Pose, Face Parsing, Face 3D Mesh, Face Liveness Detection
Person	Person Detection, Person Keypoint Detection, Person Segmentation, Fall Detection
Hand	Palm Detection, Palm Keypoint Classification, Dynamic Gesture Recognition
General Detection	YOLO Object Detection, YOLO Segmentation, YOLO Rotated Object Detection
License Plate & OCR	License Plate Recognition, YOLO License Plate Detection, OCR Recognition
Other AI	Single Object Tracking, Self-Learning, Gaze Estimation, Keyword Wakeup, Chinese Text-to-Speech
CV (cv_lite)	Edge Detection, Line Detection, Circle Detection, Rectangle Detection
CV (OpenMV)	Edge Detection, Line Detection, Circle Detection, Rectangle Detection
System	System Information, Wi-Fi Configuration

See DEMO_REGISTRY in runner.py for the full registry.

Code Structure

File	Responsibility
main.py	Entry point and main loop. Initializes display, LVGL, touch; drives the home page and app switching
config.py	Global constants: display configuration, theme colors, resource paths. DISPLAY_TYPE=None means the screen is auto-selected based on the development board model; main.py backfills DISPLAY_WIDTH/HEIGHT with the actual resolution after Display.init()
center.py	Home page icon grid and pagination
runner.py	App registry DEMO_REGISTRY, app loading, run threads, resource file checks
app_contract.py	App protocol base class Application, defines the lifecycle
app_display.py / app_visual.py	Display and drawing wrappers
ui_layout.py / lvgl_utils.py / overlay.py / splash.py	Interface layout, LVGL helpers, runtime overlays, splash screen
touch.py	Touch input driver, supports both physical touch and IDE virtual touch
i18n.py	Chinese/English text and language persistence
model_cleanup.py	Model resource cleanup helper functions, see AI Resource Management and Memory Optimization
demo_common.py	Model path and resource path constants shared by all apps
demo_*.py	Individual specific apps

App Protocol

Every app inherits app_contract.Application (AI apps usually also inherit AIBase), and implements the following methods to be schedulable by the App Center:

Member	Description
name	App display name
model_path	kmodel path; the file’s existence will be checked before launch
required_files	List of other required resource files (such as anchors, dictionaries); same existence check applies
create(display)	Class method, creates an instance and injects the display object
open() / start()	Initialize resources, start sensor
run_once()	Process one frame, return the number of results in this frame; interactive apps may return None during preview/pause, and those frames are not counted in the frame rate statistics
request_stop()	Only sets a flag, does not release resources. This method is called from the LVGL thread, while resources are created in the app’s own thread—cross-thread release will cause problems
should_run()	Returns whether to continue running
_release_owned_resources()	Final cleanup hook, guaranteed to be called only once

Note

The Application base class deliberately does not involve Sensor, Media, KPU, audio, image format, or resolution strategy—these are all decided and released by each app itself. The purpose of this design is to let pure CV apps, audio apps, and vision AI apps share the same scheduling framework.

Adding Your Own App

1. Create a new demo_myapp.py, define a class that inherits Application (and AIBase if AI inference is needed), referring to demo_face_detect.py.

2. Add a line in DEMO_REGISTRY of runner.py: "myapp": ("demo_myapp", "MyAppDemo").

3. In SHORT_MAP of center.py, add a two-letter abbreviation for it (used as a placeholder when no icon file is available).

4. Add Chinese and English names in i18n.py.

Tip

App modules are imported on demand (runner._load_demo uses __import__), so a broken optional app will not affect the App Center itself or the loading of other apps.

Development Tips

• Resource release is the first principle. The core difficulty of the application center is not the interface, but rather repeatedly loading/unloading models under limited memory. When adding a new application, be sure to implement _release_owned_resources(), and refer to AI Resource Management and Memory Optimization.

• Do not release resources in the LVGL thread. request_stop() only sets a flag; the actual release occurs when the application thread detects the flag and exits the loop.

• Use the actual resolution for layout. config.CAM_WIN_W/H are only backfilled with real values after Display.init(); do not use them to calculate layouts during the import phase.

• When frame rate is low, look at the model first, not the interface. LVGL interface refresh is only triggered on state changes; the main loop overhead is concentrated on model inference.