Restore 3.5 LD2420 wiring: OT1->GPIO21, RX->GPIO22.

Keep TFT_BL=27; do not remap UART to GPIO4.

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

firmware/README.md

@@ -3,7 +3,7 @@
 | 目录 | 板子 | 接线 |
 |------|------|------|
 | [`cyd_28r/`](cyd_28r/) | ESP32-2432S028R（ILI9341） | OT1→22，RX→27 |
-| [`cyd_35r/`](cyd_35r/) | ESP32-3248S035C（ST7796 + GT911） | OT1→22，RX→4；BL=27 |
+| [`cyd_35r/`](cyd_35r/) | ESP32-3248S035C（ST7796 + GT911） | OT1→21，RX→22；BL=27 |
 
 版本信息见各目录 `VERSION.txt`。
 

firmware/cyd_35r/VERSION.txt

@@ -1,5 +1,5 @@
 name: CYD ld2420test (cyd_35r)
-git: 5691490
+git: 786f48e
 date: 2026-10-25
 board: ESP32-3248S035 (ST7796 + GT911)
 flash_size: 4MB
@@ -11,5 +11,5 @@ offsets:
 sha256:
   bootloader.bin  3D234A7471F67B013686DABD4DEE7C1FA915C9928463616A94BC9297ACF1ABF8
   boot_app0.bin   F94C5D786A7A8FAB06AC5D10E33BF37711A6697636DC037559EA19CC410A17F0
-  firmware.bin    AD799C4C450A00B9037F9F071D45B322DCB36797836580343794B4E56CC2484D
+  firmware.bin    89D073E0AD6F64F22C068E14A442A62FB8D3E229C2F68D20A571231E26931F59
   partitions.bin  0A8B5720E7B77FF11F1462458C3A509DEE79224E5279898F26D6A2E3AE0517B7

firmware/cyd_35r/meta.json

@@ -2,7 +2,7 @@
   "boardId": "esp32-3248s035",
   "name": "CYD LD2420 radar dashboard (3.5\")",
   "summary": "Presence & distance from LD2420 mmWave radar",
-  "description": "OT1→GPIO22, RX→GPIO4. TFT_BL=27, GT911 capacitive. Distance gauge, presence LED, motion chart.",
+  "description": "OT1→GPIO21, RX→GPIO22. TFT_BL=27, GT911 capacitive. Distance gauge, presence LED, motion chart.",
   "tags": [
     "radar",
     "ld2420",