Fix 3.5C board support per CYD_PROJECT_GUIDE: BL=27, GT911 INT separate.

Correct ST7796/cyd_35r backlight, leave INT as input after reset, export firmware/cyd_35r. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-10-25 11:51:07 +08:00
parent 53d75317dd
commit e70fbd1d7f
19 changed files with 485 additions and 59 deletions
--- a/README.md
+++ b/README.md
@@ -1,18 +1,23 @@
 # 触控感应按钮计数（CYD）

-复用 [btntest](../btntest) 的 CYD + SoftSPI 触控 + LVGL 壳，针对 **电容触控感应模块**（如 TTP223）单独优化：抖沿确认、最短触摸、松手再武装。
+复用 [btntest](../btntest) 的 CYD + LVGL 壳，针对 **电容触控感应模块**（如 TTP223）单独优化：抖沿确认、最短触摸、松手再武装。

 GPIO22 读模块 OUT：每次有效触摸，屏幕计数 +1。

+板型约定见 [`../CYD_PROJECT_GUIDE.md`](../CYD_PROJECT_GUIDE.md) §A。
+
 ## 硬件

-| 项目 | 说明 |
-|------|------|
-| 板子 | CYD ESP32-2432S028R |
-| 模块 | 三脚触控感应（VCC / GND / OUT），典型 TTP223 |
-| 输出 | **GPIO22** |
+| 项目 | 2.8" · 2432S028R | 3.5" · 3248S035C |
+|------|------------------|------------------|
+| 屏 | ILI9341 240×320 | ST7796 320×480 |
+| UI | 320×240 | 480×320 |
+| 屏触控 | XPT2046 SoftSPI | GT911 I2C |
+| 背光 | **GPIO21** | **GPIO27** |
+| PlatformIO | `-e cyd` | `-e cyd_35r` |
+| 感应按钮 OUT | **GPIO22**（两板相同） | **GPIO22** |

-### 接线
+### 接线（两板相同）

 | 模块 | CYD |
 |------|-----|
@@ -44,19 +49,28 @@ GPIO22 读模块 OUT：每次有效触摸，屏幕计数 +1。
 ## 构建 / 烧录

 ```bash
+# 2.8"
 pio run -e cyd -t upload
+
+# 3.5" C（ST7796 + GT911，BL=27）
+pio run -e cyd_35r -t upload
 ```

 预编译包：

 ```powershell
+# 2.8"
 cd firmware\cyd
 .\flash.ps1
-# 或 .\flash.ps1 -Port COMx
+
+# 3.5"
+cd firmware\cyd_35r
+.\flash.ps1
 ```

 导出固件：

 ```powershell
 .\firmware\export_from_build.ps1
+.\firmware\export_from_build.ps1 -Env cyd_35r
 ```
--- a/firmware/README.md
+++ b/firmware/README.md
@@ -1,15 +1,22 @@
 # 预编译固件

-目录：[`cyd/`](cyd/)
+| 目录 | 板型 |
+|------|------|
+| [`cyd/`](cyd/) | **2.8"** ESP32-2432S028R（ILI9341 + XPT2046） |
+| [`cyd_35r/`](cyd_35r/) | **3.5"** ESP32-3248S035C（ST7796 + GT911） |

-板子：**CYD ESP32-2432S028R**（ILI9341）  
-功能：触控感应按钮（GPIO22）计数 + SoftSPI 触控 + LVGL（壳同 btntest，电容触摸专用滤波）
+功能：触控感应按钮（**GPIO22**）计数 + LVGL。背光：2.8→**21**，3.5→**27**。

 ## 刷写

 ```powershell
+# 2.8"
 cd firmware\cyd
 .\flash.ps1
+
+# 3.5"
+cd firmware\cyd_35r
+.\flash.ps1
 # 或 .\flash.ps1 -Port COM3
 ```

@@ -17,5 +24,6 @@ cd firmware\cyd

 ```powershell
 .\firmware\export_from_build.ps1
-.\firmware\export_from_build.ps1 -SkipBuild
+.\firmware\export_from_build.ps1 -Env cyd_35r
+.\firmware\export_from_build.ps1 -SkipBuild -Env cyd_35r
 ```
--- a/firmware/cyd/VERSION.txt
+++ b/firmware/cyd/VERSION.txt
@@ -1,8 +1,8 @@
 name: CYD Touch Button (cyd)
-git: 7f0f391
-date: 2026-10-23
+git: 53d7531
+date: 2026-10-25
 board: ESP32-2432S028R (ILI9341)
-features: SoftSPI touch, LVGL, capacitive touch btn on GPIO22
+features: SoftSPI touch, LVGL, capacitive touch btn GPIO22, BL=21
 flash_size: 4MB
 offsets:
  0x1000  bootloader.bin
@@ -12,5 +12,5 @@ offsets:
 sha256:
  bootloader.bin  3D234A7471F67B013686DABD4DEE7C1FA915C9928463616A94BC9297ACF1ABF8
  boot_app0.bin   F94C5D786A7A8FAB06AC5D10E33BF37711A6697636DC037559EA19CC410A17F0
-  firmware.bin    0423AA960BA1E4ADF3EFA6D40426A9047B2B9401BA27FF5E36C03F175012794F
+  firmware.bin    A9D908D034AE51042E374ABB855D63B51E7CDB4BD89017ECD96A67B5A00D9AFA
  partitions.bin  148B959CBFF1C38AA8E1D5C0BA9D612C54997B945E56A63F41223EEF650653A1
--- a/firmware/cyd/firmware.bin
+++ b/firmware/cyd/firmware.bin
--- a/firmware/cyd/meta.json
+++ b/firmware/cyd/meta.json
@@ -1,17 +1,17 @@
-{
-  "boardId": "esp32-2432s028",
-  "name": "CYD Touch Button",
-  "summary": "Capacitive touch module (TTP223-like) on GPIO22: each touch increments count",
-  "description": "Based on btntest shell. SoftSPI touch + LVGL. Capacitive debounce: majority vote, min touch 35ms, rearm after release. VCC/GND/OUT->GPIO22. Auto polarity. Touch Reset clears.",
-  "tags": [
-    "touch-button",
-    "capacitive",
-    "ttp223",
-    "gpio22",
-    "lvgl",
-    "counter"
-  ],
-  "media": {
-    "preview": "media/preview.html"
-  }
+{
+    "boardId":  "esp32-2432s028",
+    "name":  "CYD Touch Button",
+    "summary":  "Capacitive touch module (TTP223-like) on GPIO22: each touch increments count",
+    "description":  "Based on btntest shell. SoftSPI touch + LVGL. Capacitive debounce: majority vote, min touch 35ms, rearm after release. VCC/GND/OUT-\u003eGPIO22. Auto polarity. Touch Reset clears.",
+    "tags":  [
+                 "touch-button",
+                 "capacitive",
+                 "ttp223",
+                 "gpio22",
+                 "lvgl",
+                 "counter"
+             ],
+    "media":  {
+                  "preview":  "media/preview.html"
+              }
 }
--- a/firmware/cyd_35r/VERSION.txt
+++ b/firmware/cyd_35r/VERSION.txt
@@ -0,0 +1,16 @@
+name: CYD Touch Button (cyd_35r)
+git: 53d7531
+date: 2026-10-25
+board: ESP32-3248S035 (ST7796)
+features: SoftSPI/GT911 touch, LVGL, capacitive touch btn GPIO22, BL=27
+flash_size: 4MB
+offsets:
+  0x1000  bootloader.bin
+  0x8000  partitions.bin
+  0xe000  boot_app0.bin
+  0x10000 firmware.bin
+sha256:
+  bootloader.bin  3D234A7471F67B013686DABD4DEE7C1FA915C9928463616A94BC9297ACF1ABF8
+  boot_app0.bin   F94C5D786A7A8FAB06AC5D10E33BF37711A6697636DC037559EA19CC410A17F0
+  firmware.bin    F46A782C33654FA4597938724ACA0D13BF217D6B65508093E92015CCCD00BF2A
+  partitions.bin  148B959CBFF1C38AA8E1D5C0BA9D612C54997B945E56A63F41223EEF650653A1
--- a/firmware/cyd_35r/boot_app0.bin
+++ b/firmware/cyd_35r/boot_app0.bin
--- a/firmware/cyd_35r/bootloader.bin
+++ b/firmware/cyd_35r/bootloader.bin
--- a/firmware/cyd_35r/firmware.bin
+++ b/firmware/cyd_35r/firmware.bin
--- a/firmware/cyd_35r/flash.bat
+++ b/firmware/cyd_35r/flash.bat
@@ -0,0 +1,5 @@
+@echo off
+setlocal
+cd /d "%~dp0"
+powershell -NoProfile -ExecutionPolicy Bypass -File "%~dp0flash.ps1" %*
+exit /b %ERRORLEVEL%
--- a/firmware/cyd_35r/flash.ps1
+++ b/firmware/cyd_35r/flash.ps1
@@ -0,0 +1,98 @@
+# Flash archived CYD capacitive touch-button 3.5\" firmware (no rebuild needed)
+# Usage:
+#   .\flash.ps1
+#   .\flash.ps1 -Port COM5
+#   .\flash.ps1 -Port COM5 -Baud 460800
+
+param(
+  [string]$Port = "",
+  [int]$Baud = 921600
+)
+
+$ErrorActionPreference = "Stop"
+$here = Split-Path -Parent $MyInvocation.MyCommand.Path
+Set-Location $here
+
+function Find-Esptool {
+  $pio = Get-Command pio -ErrorAction SilentlyContinue
+  if (-not $pio) {
+    $pioPath = Join-Path $env:USERPROFILE "AppData\Local\Programs\Python\Python312\Scripts\pio.exe"
+    if (Test-Path $pioPath) {
+      $env:Path = "$(Split-Path $pioPath);$env:Path"
+      $pio = Get-Command pio -ErrorAction SilentlyContinue
+    }
+  }
+  if ($pio) {
+    $pkg = Join-Path $env:USERPROFILE ".platformio\packages\tool-esptoolpy\esptool.py"
+    if (Test-Path $pkg) { return @{ Kind = "py"; Path = $pkg } }
+  }
+  $py = Get-Command python -ErrorAction SilentlyContinue
+  if ($py) {
+    try {
+      & python -c "import esptool" 2>$null
+      if ($LASTEXITCODE -eq 0) { return @{ Kind = "mod"; Path = "esptool" } }
+    } catch {}
+  }
+  $esp = Get-Command esptool.py -ErrorAction SilentlyContinue
+  if ($esp) { return @{ Kind = "py"; Path = $esp.Source } }
+  return $null
+}
+
+if (-not $Port) {
+  $ports = @()
+  try {
+    Add-Type -AssemblyName System.IO.Ports -ErrorAction SilentlyContinue | Out-Null
+    $ports = [System.IO.Ports.SerialPort]::GetPortNames() | Sort-Object
+  } catch {}
+  if (-not $ports -or $ports.Count -eq 0) {
+    $ports = Get-CimInstance Win32_SerialPort -ErrorAction SilentlyContinue |
+      Select-Object -ExpandProperty DeviceID | Sort-Object
+  }
+  if (-not $ports -or $ports.Count -eq 0) {
+    Write-Error "No serial ports found. Plug in the CYD USB cable, then retry with -Port COMx"
+  }
+  if ($ports.Count -eq 1) {
+    $Port = $ports[0]
+  } else {
+    Write-Host "Available ports: $($ports -join ', ')"
+    $Port = $ports[-1]
+    Write-Host "Using last port: $Port (override with -Port)"
+  }
+}
+
+$tool = Find-Esptool
+if (-not $tool) {
+  Write-Error "esptool not found. Install PlatformIO (`pio`) or: pip install esptool"
+}
+
+$needed = @("bootloader.bin", "partitions.bin", "boot_app0.bin", "firmware.bin")
+foreach ($f in $needed) {
+  if (-not (Test-Path (Join-Path $here $f))) {
+    Write-Error "Missing $f â€?run ..\export_from_build.ps1 from repo root first"
+  }
+}
+
+$argsCommon = @(
+  "--chip", "esp32",
+  "--port", $Port,
+  "--baud", "$Baud",
+  "--before", "default_reset",
+  "--after", "hard_reset",
+  "write_flash", "-z",
+  "--flash_mode", "dio",
+  "--flash_freq", "40m",
+  "--flash_size", "4MB",
+  "0x1000", "bootloader.bin",
+  "0x8000", "partitions.bin",
+  "0xe000", "boot_app0.bin",
+  "0x10000", "firmware.bin"
+)
+
+Write-Host "Flashing $here -> $Port @ $Baud"
+if ($tool.Kind -eq "mod") {
+  & python -m esptool @argsCommon
+} else {
+  & python $tool.Path @argsCommon
+}
+if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+Write-Host "Done. Open serial monitor at 115200 if needed."
--- a/firmware/cyd_35r/media/preview.html
+++ b/firmware/cyd_35r/media/preview.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8" />
+<title>Touch</title>
+<style>
+
+  *{box-sizing:border-box;margin:0;padding:0}
+  html,body{width:320px;height:240px;overflow:hidden;background:#000;margin:0}
+  .bezel{width:320px;height:240px;background:#1a1408}
+  .screen{width:320px;height:240px;background:#0A1016;color:#EAF0F6;font:12px/1.2 system-ui,sans-serif;position:relative;overflow:hidden}
+  .muted{color:#7A8B9C}.ok{color:#3DDC97}.bad{color:#E85D4C}.acc{color:#4FC3F7}.amber{color:#FFB74D}
+  .btn{border:0;border-radius:8px;background:#243140;color:#EAF0F6;font-weight:600}
+  .btn.acc{background:#1A4A6E}.btn.on{background:#1B5E4A}.btn.warn{background:#6B3A1E}
+
+
+  .t{position:absolute;left:0;right:0;top:2px;text-align:center;font-size:26px;font-weight:700}
+  .pin{position:absolute;left:0;right:0;top:34px;text-align:center}
+  .cnt{position:absolute;left:0;right:0;top:56px;text-align:center;font-size:42px;font-weight:800;color:#4FC3F7}
+  .hint{position:absolute;left:0;right:0;top:104px;text-align:center}
+  .st{position:absolute;left:0;right:0;top:122px;text-align:center;font-size:16px;font-weight:700;color:#3DDC97}
+  .hold{position:absolute;left:0;right:0;top:144px;text-align:center;font-size:11px}
+  .bar{position:absolute;left:24px;right:24px;top:162px;height:10px;background:#1A2430;border-radius:4px;overflow:hidden}
+  .bar>i{display:block;height:100%;width:52%;background:#3DDC97}
+  .raw{position:absolute;left:0;right:0;top:176px;text-align:center;font-size:11px}
+  .act{position:absolute;left:24px;right:24px;bottom:8px;height:40px}
+
+
+/* CYD 3.5" full-bleed: non-uniform scale matches firmware UX()/UY(). */
+html,body{width:480px!important;height:320px!important;overflow:hidden!important;background:#000!important;margin:0!important;padding:0!important}
+.cyd35-scale{width:320px;height:240px;transform:scale(1.5,1.3333333333);transform-origin:0 0;overflow:hidden}
+</style>
+</head>
+<body>
+<div class="cyd35-scale">
+
+<div class="bezel"><div class="screen" id="s">
+
+  <div class="t">Touch</div>
+  <div class="pin muted">Cap OUT-&gt;GPIO22  3.3V</div>
+  <div class="cnt">5</div>
+  <div class="hint muted">count</div>
+  <div class="st">TOUCHING</div>
+  <div class="hold muted">hold 420 ms</div>
+  <div class="bar"><i></i></div>
+  <div class="raw ok">OUT HIGH  act=HIGH</div>
+  <button class="btn act" type="button">Reset</button>
+
+</div></div>
+
+</div>
+</body>
+</html>
--- a/firmware/cyd_35r/meta.json
+++ b/firmware/cyd_35r/meta.json
@@ -0,0 +1,16 @@
+{
+    "boardId":  "esp32-3248s035",
+    "name":  "CYD Touch Button (3.5\")",
+    "summary":  "Capacitive touch module (TTP223-like) on GPIO22 for 3.5\" CYD: each touch increments count",
+    "description":  "ST7796 + GT911 + LVGL. BL=GPIO27. Capacitive debounce: majority vote, min touch 35ms, rearm after release. OUT-\u003eGPIO22 (same as 2.8). Auto polarity. Screen Reset clears.",
+    "tags":  [
+                 "touch-button",
+                 "capacitive",
+                 "ttp223",
+                 "gpio22",
+                 "lvgl",
+                 "counter",
+                 "3.5",
+                 "gt911"
+             ]
+}
--- a/firmware/cyd_35r/partitions.bin
+++ b/firmware/cyd_35r/partitions.bin
--- a/firmware/export_from_build.ps1
+++ b/firmware/export_from_build.ps1
@@ -25,10 +25,12 @@ if ($Env -eq "cyd_35r") {
  $dstName = "cyd_35r"
  $boardLine = "board: ESP32-3248S035 (ST7796)"
  $boardIdHint = "esp32-3248s035"
+  $featLine = "features: SoftSPI/GT911 touch, LVGL, capacitive touch btn GPIO22, BL=27"
 } else {
  $dstName = "cyd"
  $boardLine = "board: ESP32-2432S028R (ILI9341)"
  $boardIdHint = "esp32-2432s028"
+  $featLine = "features: SoftSPI touch, LVGL, capacitive touch btn GPIO22, BL=21"
 }
 $dst = Join-Path $root ("firmware\" + $dstName)
 New-Item -ItemType Directory -Force -Path $dst | Out-Null
@@ -45,15 +47,31 @@ if (-not (Test-Path $bootApp)) {
 }
 Copy-Item $bootApp (Join-Path $dst "boot_app0.bin") -Force

+# Ensure flash scripts exist (copy from sibling folder if needed)
+foreach ($script in @("flash.ps1", "flash.bat")) {
+  $here = Join-Path $dst $script
+  if (-not (Test-Path $here)) {
+    $sibling = if ($Env -eq "cyd_35r") {
+      Join-Path $root "firmware\cyd\$script"
+    } else {
+      Join-Path $root "firmware\cyd_35r\$script"
+    }
+    if (Test-Path $sibling) {
+      Copy-Item $sibling $here -Force
+    }
+  }
+}
+
 $git = ""
 try { $git = (git -C $root rev-parse --short HEAD).Trim() } catch { $git = "unknown" }
 $date = Get-Date -Format "yyyy-MM-dd"
 $hashes = Get-ChildItem (Join-Path $dst "*.bin") | Get-FileHash -Algorithm SHA256
 $lines = @(
-  "name: CYD touchbtntest ($dstName)",
+  "name: CYD Touch Button ($dstName)",
  "git: $git",
  "date: $date",
  $boardLine,
+  $featLine,
  "flash_size: 4MB",
  "offsets:",
  "  0x1000  bootloader.bin",
@@ -73,8 +91,8 @@ if (Test-Path $metaPath) {
  try {
    $meta = Get-Content $metaPath -Raw | ConvertFrom-Json
    $meta.boardId = $boardIdHint
-    if ($Env -eq "cyd_35r" -and $meta.name -notmatch "3\.5") {
-      $meta.name = ($meta.name -replace "\s*$","") + " (3.5\")"
+    if ($Env -eq "cyd_35r" -and $meta.name -notmatch '3\.5') {
+      $meta.name = ($meta.name -replace '\s*$','') + ' (3.5")'
    }
    $meta | ConvertTo-Json -Depth 8 | Set-Content -Encoding utf8 $metaPath
  } catch {
--- a/include/pins.h
+++ b/include/pins.h
@@ -1,6 +1,7 @@
 #pragma once

 // Board pins — 2.8" default; 3.5" when CYD_BOARD_3248S035 is set (env:cyd_35r)
+// See ../CYD_PROJECT_GUIDE.md §A

 #if defined(CYD_BOARD_3248S035)
 #define TFT_BL_PIN 27
@@ -8,19 +9,27 @@
 #define SCREEN_HEIGHT 480
 #define UI_HOR_RES    480
 #define UI_VER_RES    320
+/* 3.5C capacitive GT911 (ESP32-3248S035C). GPIO33 is I2C SDA, not TOUCH_CS.
+ * BL=27; INT=21 (not shared with BL). Touch-btn OUT stays GPIO22. */
+#define CYD_GT911_SDA  33
+#define CYD_GT911_SCL  32
+#define CYD_GT911_INT  21
+#define CYD_GT911_RST  25
+#define CYD_TFT_CS     15
 #else
 #define TFT_BL_PIN 21
 #define SCREEN_WIDTH  240
 #define SCREEN_HEIGHT 320
 #define UI_HOR_RES    320
 #define UI_VER_RES    240
-#endif
-
+/* 2.8" CYD: SoftSPI touch. BL=21; touch-btn OUT GPIO22. */
 #define CYD_TOUCH_IRQ  36
 #define CYD_TOUCH_MOSI 32
 #define CYD_TOUCH_MISO 39
 #define CYD_TOUCH_CLK  25
 #define CYD_TOUCH_CS   33
+#define CYD_TFT_CS     15
+#endif

 /* Map 320x240 design coordinates onto the active UI resolution (identity on 2.8"). */
 #define UX(x) ((int)(((long)(x) * (UI_HOR_RES)) / 320))
@@ -28,5 +37,12 @@
 #define UW(w) UX(w)
 #define UH(h) UY(h)

+/* Partial frame buffer: 3.5 needs smaller ratio to fit DRAM. */
+#if defined(CYD_BOARD_3248S035)
+#define DRAW_BUF_DIV 20
+#else
+#define DRAW_BUF_DIV 10
+#endif

+/* Primary peripheral pin — same on 2.8 and 3.5 */
 #define BTN_PIN 22
--- a/platformio.ini
+++ b/platformio.ini
@@ -55,19 +55,27 @@ build_flags =

 extra_scripts = pre:copy_lv_conf.py

-; Optional 3.5" CYD ESP32-3248S035 (ST7796 resistive). Default remains [env:cyd].
+; Optional 3.5" CYD ESP32-3248S035C (ST7796 + GT911 capacitive). Default [env:cyd].
 ; Build: pio run -e cyd_35r
+; Keep TOUCH_CS=-1 — GPIO33 is GT911 SDA, not resistive touch CS.
+; TFT_BL=GPIO27 (not 21 — 21 is GT911 INT on C boards). See ../CYD_PROJECT_GUIDE.md §A
 [env:cyd_35r]
 extends = env:cyd
+build_unflags =
+  -DILI9341_2_DRIVER=1
+  -DTFT_WIDTH=240
+  -DTFT_HEIGHT=320
+  -DTFT_BL=21
+  -DLV_MEM_SIZE=49152
 build_flags =
  ${env:cyd.build_flags}
-  -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
+  -DUSE_HSPI_PORT
+  -DSUPPORT_TRANSACTIONS
+  -DTFT_RGB_ORDER=TFT_BGR
+  -DLV_MEM_SIZE=32768

--- a/src/main.cpp
+++ b/src/main.cpp
@@ -7,7 +7,7 @@
 #include "ui.h"

 static constexpr uint32_t DRAW_BUF_SIZE =
-    (SCREEN_WIDTH * SCREEN_HEIGHT / 10 * (LV_COLOR_DEPTH / 8));
+    (SCREEN_WIDTH * SCREEN_HEIGHT / DRAW_BUF_DIV * (LV_COLOR_DEPTH / 8));
 static uint32_t draw_buf[DRAW_BUF_SIZE / 4];

 void setup() {
@@ -17,6 +17,13 @@ void setup() {
  Serial.printf("LVGL %d.%d.%d | Capacitive touch btn GPIO%d\n",
                lv_version_major(), lv_version_minor(), lv_version_patch(),
                BTN_PIN);
+#if defined(CYD_BOARD_3248S035)
+  Serial.printf("Board: 3.5C ST7796 %dx%d UI %dx%d BL=%d\n", SCREEN_WIDTH,
+                SCREEN_HEIGHT, UI_HOR_RES, UI_VER_RES, TFT_BL_PIN);
+#else
+  Serial.printf("Board: 2.8R ILI9341 %dx%d UI %dx%d BL=%d\n", SCREEN_WIDTH,
+                SCREEN_HEIGHT, UI_HOR_RES, UI_VER_RES, TFT_BL_PIN);
+#endif
  Serial.println("BOOT_OK");

  pinMode(TFT_BL_PIN, OUTPUT);
--- a/src/touch.cpp
+++ b/src/touch.cpp
@@ -3,10 +3,13 @@

 #include <Arduino.h>

+#if defined(CYD_BOARD_3248S035)
+#include <Wire.h>
+#endif
+
 /**
- * SoftSPI XPT2046
- * BL↔TR 是矩形主对角线镜像（XY 对调），不是 180°（180° 会搞成 TL↔BR）。
- * 先按 rot2 得到旧 UI，再做对角修正，反变换喂给 LVGL 270。
+ * 2.8": dedicated SoftSPI + BL/TR diagonal fix.
+ * 3.5C (3248S035C): capacitive GT911 on I2C SDA33/SCL32/INT21/RST25.
 */

 int16_t g_dbg_phys_x = -1;
@@ -15,6 +18,181 @@ int16_t g_dbg_logic_x = -1;
 int16_t g_dbg_logic_y = -1;
 bool g_dbg_touch_down = false;

+static int16_t clampi(int32_t v, int32_t lo, int32_t hi) {
+  if (v < lo) {
+    return (int16_t)lo;
+  }
+  if (v > hi) {
+    return (int16_t)hi;
+  }
+  return (int16_t)v;
+}
+
+#if defined(CYD_BOARD_3248S035)
+
+/* Minimal GT911 — no config rewrite (TAMC setResolution can hang Wire). */
+static uint8_t s_gt_addr = 0x5D;
+static constexpr uint16_t GT_POINT_INFO = 0x814E;
+static constexpr uint16_t GT_POINT_1 = 0x814F;
+
+static bool gt_write8(uint16_t reg, uint8_t val) {
+  Wire.beginTransmission(s_gt_addr);
+  Wire.write((uint8_t)(reg >> 8));
+  Wire.write((uint8_t)(reg & 0xFF));
+  Wire.write(val);
+  return Wire.endTransmission() == 0;
+}
+
+static bool gt_read(uint16_t reg, uint8_t *buf, uint8_t len) {
+  Wire.beginTransmission(s_gt_addr);
+  Wire.write((uint8_t)(reg >> 8));
+  Wire.write((uint8_t)(reg & 0xFF));
+  if (Wire.endTransmission(false) != 0) {
+    return false;
+  }
+  const uint8_t n = Wire.requestFrom(s_gt_addr, len);
+  if (n != len) {
+    return false;
+  }
+  for (uint8_t i = 0; i < len; i++) {
+    buf[i] = Wire.read();
+  }
+  return true;
+}
+
+static bool gt_probe(uint8_t addr) {
+  Wire.beginTransmission(addr);
+  return Wire.endTransmission() == 0;
+}
+
+/* TAMC-compatible address select: INT low => 0x5D, INT high => 0x14 */
+static void gt_hw_reset(bool addr_0x14) {
+  pinMode(CYD_GT911_INT, OUTPUT);
+  pinMode(CYD_GT911_RST, OUTPUT);
+  digitalWrite(CYD_GT911_INT, LOW);
+  digitalWrite(CYD_GT911_RST, LOW);
+  delay(10);
+  digitalWrite(CYD_GT911_INT, addr_0x14 ? HIGH : LOW);
+  delay(1);
+  digitalWrite(CYD_GT911_RST, HIGH);
+  delay(5);
+  digitalWrite(CYD_GT911_INT, LOW);
+  delay(50);
+  /* Backlight is GPIO27 — leave INT as input for polling. */
+  pinMode(CYD_GT911_INT, INPUT);
+  delay(50);
+}
+
+static bool gt_find_addr() {
+  for (uint8_t a : {uint8_t(0x5D), uint8_t(0x14)}) {
+    if (gt_probe(a)) {
+      s_gt_addr = a;
+      return true;
+    }
+  }
+  return false;
+}
+
+void touch_init() {
+  Serial.println("Touch: GT911 I2C capacitive (3.5C) minimal");
+  Wire.begin(CYD_GT911_SDA, CYD_GT911_SCL);
+  Wire.setClock(100000);
+#if defined(WIRE_HAS_TIMEOUT) || defined(ESP32)
+  Wire.setTimeOut(50);
+#endif
+
+  /* Prefer power-on address (previously 0x5D without reset). */
+  if (!gt_find_addr()) {
+    Serial.println("GT911 not found — hw reset 0x5D");
+    gt_hw_reset(false);
+    if (!gt_find_addr()) {
+      Serial.println("GT911 not found — hw reset 0x14");
+      gt_hw_reset(true);
+      gt_find_addr();
+    }
+  }
+
+  Serial.printf("GT911 probe 0x5D=%s 0x14=%s using=0x%02X\n",
+                gt_probe(0x5D) ? "OK" : "no", gt_probe(0x14) ? "OK" : "no",
+                s_gt_addr);
+  Serial.printf("GT911 SDA=%d SCL=%d INT=%d RST=%d BL=%d\n", CYD_GT911_SDA,
+                CYD_GT911_SCL, CYD_GT911_INT, CYD_GT911_RST, TFT_BL_PIN);
+  Serial.print("I2C scan:");
+  for (uint8_t a = 1; a < 127; a++) {
+    if (gt_probe(a)) {
+      Serial.printf(" 0x%02X", a);
+    }
+  }
+  Serial.println();
+}
+
+void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
+  uint8_t info = 0;
+  static uint32_t last_log = 0;
+  const bool do_log = (millis() - last_log > 200);
+
+  if (!gt_read(GT_POINT_INFO, &info, 1)) {
+    data->state = LV_INDEV_STATE_RELEASED;
+    g_dbg_touch_down = false;
+    if (do_log) {
+      last_log = millis();
+      Serial.println("TouchProbe GT911 I2C err");
+    }
+    return;
+  }
+
+  const uint8_t touches = info & 0x0F;
+  const bool buffered = (info & 0x80) != 0;
+
+  if (!buffered || touches == 0) {
+    if (buffered) {
+      gt_write8(GT_POINT_INFO, 0);
+    }
+    data->state = LV_INDEV_STATE_RELEASED;
+    g_dbg_touch_down = false;
+    return;
+  }
+
+  uint8_t pt[7];
+  if (!gt_read(GT_POINT_1, pt, 7)) {
+    gt_write8(GT_POINT_INFO, 0);
+    data->state = LV_INDEV_STATE_RELEASED;
+    g_dbg_touch_down = false;
+    return;
+  }
+  gt_write8(GT_POINT_INFO, 0);
+
+  const int16_t raw_x = (int16_t)(pt[1] | (pt[2] << 8));
+  const int16_t raw_y = (int16_t)(pt[3] | (pt[4] << 8));
+
+  /* Native 320x480 → LVGL 270 + mirror long axis for correct L/R.
+   * UI ≈ (H-1-raw_y, raw_x). */
+  const int16_t nx = clampi(raw_x, 0, SCREEN_WIDTH - 1);
+  const int16_t ny = clampi(raw_y, 0, SCREEN_HEIGHT - 1);
+  const int16_t feed_x = (int16_t)((SCREEN_WIDTH - 1) - nx);
+  const int16_t feed_y = (int16_t)((SCREEN_HEIGHT - 1) - ny);
+  const int16_t ui_x = (int16_t)((SCREEN_HEIGHT - 1) - ny);
+  const int16_t ui_y = nx;
+
+  g_dbg_phys_x = raw_x;
+  g_dbg_phys_y = raw_y;
+  g_dbg_logic_x = ui_x;
+  g_dbg_logic_y = ui_y;
+  g_dbg_touch_down = true;
+
+  if (do_log) {
+    last_log = millis();
+    Serial.printf("Touch HIT GT911 raw(%d,%d) ~ui(%d,%d)\n", raw_x, raw_y,
+                  ui_x, ui_y);
+  }
+
+  data->point.x = feed_x;
+  data->point.y = feed_y;
+  data->state = LV_INDEV_STATE_PRESSED;
+}
+
+#else
+
 static void soft_write(uint8_t data) {
  for (int i = 7; i >= 0; --i) {
    digitalWrite(CYD_TOUCH_MOSI, (data >> i) & 1);
@@ -49,16 +227,6 @@ static uint16_t xpt_read(uint8_t cmd) {
  return v;
 }

-static int16_t clampi(int32_t v, int32_t lo, int32_t hi) {
-  if (v < lo) {
-    return (int16_t)lo;
-  }
-  if (v > hi) {
-    return (int16_t)hi;
-  }
-  return (int16_t)v;
-}
-
 void touch_init() {
  pinMode(CYD_TOUCH_CS, OUTPUT);
  pinMode(CYD_TOUCH_CLK, OUTPUT);
@@ -94,8 +262,6 @@ void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
  x = clampi(x, 0, SCREEN_WIDTH - 1);
  y = clampi(y, 0, SCREEN_HEIGHT - 1);

-  // 旧 UI（LVGL270）：(y, 239-x) — 该空间里 BL↔TR，做主对角线镜像
-  // (ux,uy) -> (uy*(319/239), ux*(239/319))
  const int32_t old_ux = y;
  const int32_t old_uy = (SCREEN_WIDTH - 1) - x;
  int16_t ui_x = clampi((old_uy * (UI_HOR_RES - 1)) / (UI_VER_RES - 1), 0,
@@ -103,7 +269,6 @@ void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
  int16_t ui_y = clampi((old_ux * (UI_VER_RES - 1)) / (UI_HOR_RES - 1), 0,
                        UI_VER_RES - 1);

-  // 反变换喂 LVGL，使最终落在 (ui_x, ui_y)
  const int16_t feed_x = (int16_t)((SCREEN_WIDTH - 1) - ui_y);
  const int16_t feed_y = ui_x;

@@ -123,3 +288,5 @@ void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
  data->point.y = feed_y;
  data->state = LV_INDEV_STATE_PRESSED;
 }
+
+#endif