docs(tactility-app-dev): note device_get_* not exported; use device_find_* legacy API

Flashed 0.8.0-dev firmware exports device_find_* but not the newer device_get_* out-param API. verify_symbols.py compares vs local firmware source and can pass even when the flashed firmware differs — confirm on-device via serial (/dev/cu.usbmodem*, 115200). Record the local extern-declare workaround.
2026-08-19 21:19:28 -04:00
parent f785bd3fb2
commit 479a448900
2 changed files with 7 additions and 0 deletions
@@ -121,6 +121,7 @@ Keep app source as pure C (no `auto`, no lambdas in `.c`) or rename to `.cpp`.
 Tactility firmware exports symbols via `ESP_ELFSYM_EXPORT` / `DEFINE_MODULE_SYMBOL` in `firmware/Modules/lvgl-module/source/symbols.c`. If ELF references an unexported symbol → device modal `Error / Application failed to start: missing symbol`, heap still healthy (~31KB free) → NOT OOM.

 Known missing on 0.8.0-dev:
+- `device_get_by_name` / `device_get_first_by_type` (out-param API) → **Not exported** by flashed firmware; use legacy exported `device_find_by_name` / `device_find_first_by_type` (declare them locally — newer SDK headers dropped them). Gotcha: `verify_symbols.py` compares vs local firmware SOURCE and can pass even when the flashed firmware's export table differs — confirm on-device via serial (`/dev/cu.usbmodem*`, 115200): `E ELF: Can't find symbol X`.
 - `lv_font_montserrat_14/18` → use `lvgl_get_text_font(SMALL/DEFAULT/LARGE)` via `tactility/lvgl_fonts.h`
 - `lv_obj_set_style_bg_grad_color/dir/stop`, `LV_OPA_95/5`, `LV_SYMBOL_STAR` → use solid colors, COVER/90
 - `lv_obj_set_style_max_width` → use `LV_PCT(92)` fixed percents for gutters