This project renders pre-built binary watchfaces on ESP32 using LVGL. A Kotlin script is used to transform the binary watchfaces into LVGL code, which is then compiled for the ESP32 display.
Create wathfaces for ZSWatch
Watchfaces can be obtained from watch-face-wearfit or Chronos Dials. Since this project uses a 240x240 screen, watchfaces of the same resolution are recommended.
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The Kotlin script bin2lvgl.kt has been compiled into bin2lvgl.jar.
You can also recompile it with kotlinc bin2lvgl.kt -include-runtime -d bin2lvgl.jar.
To convert the watchface, simply run java -jar bin2lvgl.jar watchface.bin Name, and LVGL code will be generated into a folder.
On Windows, just drag and drop the bin file to convert.bat
In the main.cpp, include the watchface.h file.
By default the watchface is not enabled. You need to uncomment the ENABLE_FACE definition
You will need to implement a callback for registering the watchface and events:
void onFaceEvent(lv_event_t *e){
}
void registerWatchface_cb(const char *name, const lv_img_dsc_t *preview, lv_obj_t **watchface)
{
// name -> name of the watchface, this is the second parameter passed when converting the watchface to LVGL code
// preview -> the preview image of the watchface
// watchface -> pointer to the root object of the watchface
}
After initializing LVGL, initialize the watchface:
init_face_watchface(registerWatchface_cb); // need to pass the callback function
lv_disp_load_scr(face_watchface); // load the watchface root object to display it
In the loop, use the functions to update the watchface:
update_time_watchface(sec, min, hr, md, am, dy, mt, yr, wk);
update_weather_watchface(temp, ic);
update_status_watchface(bat, con);
update_activity_watchface(2735, 357, 345);
update_health_watchface(76, 97);
update_all_watchface(/*..all params */);
update_check_watchface(home, /*..all params */); // this check if the home object and the root object of the watchface are similar
// this is useful if your have multiple watchfaces, only the active one will be updated
This project implements using multiple watchfaces using a face_selector object. Note that the number of watchfaces you can compile is limited by the target ESP32 flash size.
You will also need a ui_home object for multiple watchfaces. Set the active watchface to this object
This project only demonstrates watchfaces that are functional to display time by leveraging the ChronosESP32 library.
For other advanced features such as notifications and control, check out the esp32-c3-mini and dt78-esp32-firmware projects.
