CardputerZero-AppBuilder/sdk

CardputerZero App SDK

Headers and CMake helpers for building LVGL apps that load into the emulator and, unchanged, into APPLaunch on the device.

Contents

sdk/
├── include/
│   ├── cz_app.h        # App ABI: app_main / app_event / CZ_EV_*
│   └── lv_conf.h       # Pinned LVGL v9.5 config (must byte-match host's)
└── cmake/
    └── CZApp.cmake     # cz_add_lvgl_app(target SOURCES ...)

Writing an app

#include <cz_app.h>

static lv_obj_t *label;

void app_main(lv_obj_t *parent) {
    label = lv_label_create(parent);
    lv_label_set_text(label, "Hello, CardputerZero!");
    lv_obj_center(label);
}

void app_event(int type, void *data) {
    (void)data;
    if (type == CZ_EV_EXIT_REQUEST && label) {
        lv_obj_del(label);
        label = NULL;
    }
}

And a CMakeLists.txt:

cmake_minimum_required(VERSION 3.16)
project(hello_cz C)

# Point at the SDK (usually the CardputerZero-AppBuilder sdk/ dir).
list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/../../sdk/cmake")
include(CZApp)

cz_add_lvgl_app(hello_cz SOURCES src/hello_cz.c)

Build with plain CMake; czdev build / czdev run wrap this for you.

Non-negotiable rules

See docs/DESKTOP_DEV.md for the full rationale.

1. Don't call lv_init() or lv_display_create().
2. Use this SDK's lv_conf.h — don't ship your own.
3. Export only extern "C" symbols (app_main, app_event).
4. Delete widgets you own in CZ_EV_EXIT_REQUEST.