Align 3.5C pins with CYD_PROJECT_GUIDE: TFT_BL=27, SGP30 SDA22/SCL21.

Leave 2.8 wiring unchanged; release GT911 INT after reset so SCL21 can share CN1.

Co-authored-by: Cursor <cursoragent@cursor.com>

platformio.ini

@@ -1,6 +1,5 @@
-; CYD ESP32-2432S028R â€?LVGL SGP30 空气质é‡<C3A9>仪表ç›?
-; SGP30 SDA -> GPIO22, SCL -> GPIO27
-
+; CYD LVGL SGP30 air quality dashboard
+; 2.8: SDA=22 SCL=27 BL=21; 3.5C: SDA=22 SCL=21 BL=27 (see ../CYD_PROJECT_GUIDE.md)
 [platformio]
 default_envs = cyd_28r
 
@@ -47,12 +46,12 @@ build_flags =
   -D LV_CONF_INCLUDE_SIMPLE=1
   -I include
 
-; 标准 CYD 2.8" 电阻�(ILI9341)
+; 标准 CYD 2.8" 电阻<EFBFBD>?(ILI9341)
 [env:cyd_28r]
 build_flags =
   ${env.build_flags}
 
-; 颜色å<EFBFBD><EFBFBD>相版本（若画é<EFBFBD>¢è‰²å<EFBFBD><EFBFBD>/å<>‘白å<C2BD>¯æ”¹ç”¨æ­¤çŽ¯å¢ƒï¼?
+; 颜色反相版本（若画面色偏/发白可改用此环境<E78EAF>?
 [env:cyd_28r_inv]
 build_flags =
   ${env.build_flags}
@@ -67,18 +66,29 @@ build_flags =
   -D TFT_RGB_ORDER=TFT_BGR
   -D TFT_INVERSION_ON=1
 
-; Optional 3.5" CYD ESP32-3248S035 (ST7796 resistive). Default remains cyd_28r.
+; Optional 3.5" CYD ESP32-3248S035C (ST7796 + GT911 capacitive). Default remains cyd_28r.
 ; Build: pio run -e cyd_35r
+; Keep TOUCH_CS=-1 — GPIO33 is GT911 SDA, not resistive touch CS.
+; TFT_BL=27 (not 21 — 21 is GT911 INT / SGP30 SCL). GT911 uses Wire1.
 [env:cyd_35r]
+lib_deps =
+  lvgl/lvgl@9.2.2
+  bodmer/TFT_eSPI@2.5.43
+  adafruit/Adafruit SGP30 Sensor@^2.0.3
+  adafruit/Adafruit BusIO@^1.16.1
 build_flags =
   ${env.build_flags}
-  -U ILI9341_2_DRIVER
-  -D ST7796_DRIVER=1
-  -U TFT_WIDTH
-  -U TFT_HEIGHT
-  -D TFT_WIDTH=320
-  -D TFT_HEIGHT=480
-  -U TFT_BL
-  -D TFT_BL=27
-  -D CYD_BOARD_3248S035=1
+  -UILI9341_2_DRIVER
+  -DST7796_DRIVER=1
+  -UTFT_WIDTH
+  -UTFT_HEIGHT
+  -DTFT_WIDTH=320
+  -DTFT_HEIGHT=480
+  -UTFT_BL
+  -DTFT_BL=27
+  -DCYD_BOARD_3248S035=1
+  -DSUPPORT_TRANSACTIONS
+  -DTFT_RGB_ORDER=TFT_BGR
+  -ULV_MEM_SIZE
+  -DLV_MEM_SIZE=32768