feat(lua): add lua_driver_twai -- TWAI (CAN bus) Lua driver

components/common/app_claw/Kconfig

@@ -215,6 +215,15 @@ menu "App Claw Config"
                 Enable the UART Lua driver and keep app_claw's direct dependency
                 on lua_driver_uart when Lua capability is enabled.
 
+        config APP_CLAW_LUA_DRIVER_TWAI
+            bool "Enable TWAI Lua driver"
+            default y if SOC_TWAI_SUPPORTED
+            default n
+            help
+                Enable the TWAI Lua driver (Two-Wire Automotive Interface / CAN bus)
+                and keep app_claw's direct dependency on lua_driver_twai when Lua
+                capability is enabled. Defaults to n on chips without TWAI hardware.
+
         comment "--- Higher-level modules (lua_module) ---"
 
         config APP_CLAW_LUA_MODULE_AUDIO
@@ -346,13 +355,6 @@ menu "App Claw Config"
                 Enable the LED strip Lua module and keep app_claw's direct dependency
                 on lua_module_led_strip when Lua capability is enabled.
 
-        config APP_CLAW_LUA_MODULE_LVGL
-            bool "Enable LVGL Lua module"
-            default n
-            help
-                Enable the LVGL Lua module and keep app_claw's direct dependency
-                on lua_module_lvgl when Lua capability is enabled.
-
         config APP_CLAW_LUA_MODULE_MAGNETOMETER
             bool "Enable magnetometer Lua module"
             default n

components/common/app_claw/app_lua_modules.c

@@ -35,6 +35,9 @@
 #if CONFIG_APP_CLAW_LUA_DRIVER_UART
 #include "lua_driver_uart.h"
 #endif
+#if CONFIG_APP_CLAW_LUA_DRIVER_TWAI
+#include "lua_driver_twai.h"
+#endif
 
 /* --- lua_module (higher-level modules) --- */
 #if CONFIG_APP_CLAW_LUA_MODULE_AUDIO && defined(CONFIG_ESP_BOARD_DEV_AUDIO_CODEC_SUPPORT)
@@ -88,9 +91,6 @@
 #if CONFIG_APP_CLAW_LUA_MODULE_LED_STRIP
 #include "lua_module_led_strip.h"
 #endif
-#if CONFIG_APP_CLAW_LUA_MODULE_LVGL
-#include "lua_module_lvgl.h"
-#endif
 #if CONFIG_APP_CLAW_LUA_MODULE_MAGNETOMETER
 #include "lua_module_magnetometer.h"
 #endif
@@ -284,6 +284,14 @@ static esp_err_t app_lua_register_uart(const char *fatfs_base_path)
 }
 #endif
 
+#if CONFIG_APP_CLAW_LUA_DRIVER_TWAI
+static esp_err_t app_lua_register_twai(const char *fatfs_base_path)
+{
+    (void)fatfs_base_path;
+    return lua_driver_twai_register();
+}
+#endif
+
 /* --- lua_module register wrappers --- */
 
 #if CONFIG_APP_CLAW_LUA_MODULE_AUDIO && defined(CONFIG_ESP_BOARD_DEV_AUDIO_CODEC_SUPPORT)
@@ -422,14 +430,6 @@ static esp_err_t app_lua_register_led_strip(const char *fatfs_base_path)
 }
 #endif
 
-#if CONFIG_APP_CLAW_LUA_MODULE_LVGL
-static esp_err_t app_lua_register_lvgl(const char *fatfs_base_path)
-{
-    (void)fatfs_base_path;
-    return lua_module_lvgl_register();
-}
-#endif
-
 #if CONFIG_APP_CLAW_LUA_MODULE_MAGNETOMETER
 static esp_err_t app_lua_register_magnetometer(const char *fatfs_base_path)
 {
@@ -483,6 +483,9 @@ static const app_lua_module_entry_t s_lua_module_entries[] = {
 #endif
 #if CONFIG_APP_CLAW_LUA_DRIVER_UART
     { "uart", "UART", app_lua_register_uart },
+#endif
+#if CONFIG_APP_CLAW_LUA_DRIVER_TWAI
+    { "twai", "TWAI", app_lua_register_twai },
 #endif
     /* --- lua_module (higher-level modules) --- */
 #if CONFIG_APP_CLAW_LUA_MODULE_AUDIO && defined(CONFIG_ESP_BOARD_DEV_AUDIO_CODEC_SUPPORT)
@@ -536,9 +539,6 @@ static const app_lua_module_entry_t s_lua_module_entries[] = {
 #if CONFIG_APP_CLAW_LUA_MODULE_LED_STRIP
     { "led_strip", "LED Strip", app_lua_register_led_strip },
 #endif
-#if CONFIG_APP_CLAW_LUA_MODULE_LVGL
-    { "lvgl", "LVGL", app_lua_register_lvgl },
-#endif
 #if CONFIG_APP_CLAW_LUA_MODULE_MAGNETOMETER
     { "magnetometer", "Magnetometer", app_lua_register_magnetometer },
 #endif
@@ -628,9 +628,6 @@ static const app_lua_module_info_t s_lua_module_infos[] = {
 #if CONFIG_APP_CLAW_LUA_MODULE_LED_STRIP
     { "led_strip", "LED Strip" },
 #endif
-#if CONFIG_APP_CLAW_LUA_MODULE_LVGL
-    { "lvgl", "LVGL" },
-#endif
 #if CONFIG_APP_CLAW_LUA_MODULE_MAGNETOMETER
     { "magnetometer", "Magnetometer" },
 #endif

components/common/app_claw/idf_component.yml

@@ -145,6 +145,12 @@ dependencies:
       - if: $CONFIG{APP_CLAW_LUA_DRIVER_UART} == True
     path: ../../lua_modules/lua_driver_uart
 
+  lua_driver_twai:
+    rules:
+      - if: $CONFIG{APP_CLAW_CAP_LUA} == True
+      - if: $CONFIG{APP_CLAW_LUA_DRIVER_TWAI} == True
+    path: ../../lua_modules/lua_driver_twai
+
   # --- lua_module (higher-level modules) ---
 
   lua_module_audio:
@@ -259,12 +265,6 @@ dependencies:
       - if: $CONFIG{APP_CLAW_LUA_MODULE_LED_STRIP} == True
     path: ../../lua_modules/lua_module_led_strip
 
-  lua_module_lvgl:
-    rules:
-      - if: $CONFIG{APP_CLAW_CAP_LUA} == True
-      - if: $CONFIG{APP_CLAW_LUA_MODULE_LVGL} == True
-    path: ../../lua_modules/lua_module_lvgl
-
   lua_module_magnetometer:
     rules:
       - if: $CONFIG{APP_CLAW_CAP_LUA} == True

components/lua_modules/lua_driver_twai/CMakeLists.txt

@@ -0,0 +1,12 @@
+idf_component_register(
+    SRCS
+        "src/lua_driver_twai.c"
+    INCLUDE_DIRS
+        "src"
+    REQUIRES
+        cap_lua
+        esp_driver_twai
+        freertos
+)
+
+idf_component_set_property(${COMPONENT_NAME} WHOLE_ARCHIVE TRUE)

components/lua_modules/lua_driver_twai/README.md

@@ -0,0 +1,70 @@
+# Lua TWAI (CAN bus)
+
+This module exposes the ESP32 TWAI (Two-Wire Automotive Interface / CAN bus) peripheral
+to Lua scripts. It wraps the ESP-IDF v6 `esp_driver_twai` API and uses a FreeRTOS queue
+to buffer received frames so scripts can poll with a timeout.
+
+## How to call
+- Import it with `local twai = require("twai")`
+- Create a node with `local can = twai.new(tx_gpio, rx_gpio, bitrate [, opts])`
+  - `tx_gpio`, `rx_gpio`: GPIO numbers for TWAI TX and RX lines
+  - `bitrate`: bus speed in bits/s, e.g. `125000`, `250000`, `500000`, `1000000`
+  - `opts` (optional table):
+    - `listen_only`: `true` to monitor without transmitting (default `false`)
+    - `loopback`: `true` for self-test mode (default `false`)
+- `can:enable()` — start the node (must call before send/receive)
+- `can:disable()` — stop the node (node handle is still valid)
+- `can:send(id, data [, is_extended [, is_rtr]])` — transmit a frame
+  - `id`: 11-bit (standard) or 29-bit (extended) arbitration ID
+  - `data`: string of up to 8 bytes, e.g. `"\x01\x02\x03"`
+  - `is_extended`: `true` for 29-bit ID (default `false`)
+  - `is_rtr`: `true` for Remote Frame (default `false`)
+- `can:receive([timeout_ms])` → table or `nil`
+  - `timeout_ms`: how long to wait for a frame (`0` = non-blocking, `-1` = forever)
+  - Returns `{id=..., data="...", extended=bool, rtr=bool}` or `nil` on timeout
+- `can:status()` → `{state, tx_errors, rx_errors, tx_queue_remaining, bus_errors}`
+  - `state`: `"active"`, `"warning"`, `"passive"`, or `"bus_off"`
+- `can:recover()` — initiate bus-off recovery
+- `can:close()` — disable and delete the node, free resources
+
+## Example: send and receive
+```lua
+local twai = require("twai")
+
+local can = twai.new(10, 11, 500000)
+can:enable()
+
+-- Send a standard frame (11-bit ID)
+can:send(0x123, "\x01\x02\x03\x04")
+
+-- Send an extended frame (29-bit ID)
+can:send(0x1ABCDEF, "\xFF\xFE", true)
+
+-- Poll for an incoming frame (100 ms timeout)
+local frame = can:receive(100)
+if frame then
+    print(string.format("id=0x%X ext=%s rtr=%s data=%q",
+        frame.id, tostring(frame.extended), tostring(frame.rtr), frame.data))
+end
+
+local st = can:status()
+print("state:", st.state, "tx_err:", st.tx_errors, "rx_err:", st.rx_errors)
+
+can:close()
+```
+
+## Example: continuous listener
+```lua
+local twai = require("twai")
+local can = twai.new(10, 11, 250000, {listen_only = true})
+can:enable()
+
+while true do
+    local f = can:receive(500)
+    if f then
+        print(string.format("[0x%03X] %s", f.id, f.data:gsub(".", function(c)
+            return string.format("%02X ", c:byte())
+        end)))
+    end
+end
+```