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>
2026-10-25 10:53:33 +08:00
parent 1b2fe27fd9
commit ee2ca3edfc
16 changed files with 487 additions and 92 deletions
--- a/README.md
+++ b/README.md
@@ -1,20 +1,22 @@
 # CYD SGP30 空气质量仪表盘

-ESP32 Cheap Yellow Display（ESP32-2432S028R）+ SGP30 + LVGL 空气质量仪表盘。
+ESP32 Cheap Yellow Display + SGP30 + LVGL 空气质量仪表盘。

-布局与交互参考同目录下的 [temperature](../temperature) 温湿度项目。
+默认 **2.8" ESP32-2432S028R**；可选 **3.5" ESP32-3248S035C**（`cyd_35r`）。  
+引脚约定见同目录 [CYD_PROJECT_GUIDE.md](../CYD_PROJECT_GUIDE.md)；布局参考 [temperature](../temperature)。

 ## 硬件

-| 项目 | 说明 |
-|------|------|
-| 板子 | CYD ESP32-2432S028R（2.8" ILI9341） |
-| 传感器 | SGP30（eCO2 / TVOC） |
-| SDA | **GPIO22** |
-| SCL | **GPIO27** |
-| 供电 | USB 5V；传感器接 **3.3V** |
+| 项目 | 2.8" · 2432S028R | 3.5" C · 3248S035C |
+|------|------------------|---------------------|
+| 屏驱 | ILI9341 | ST7796 |
+| 触控 | XPT2046 SoftSPI | GT911 Wire1（SDA33/SCL32/INT21/RST25） |
+| 背光 TFT_BL | **GPIO21** | **GPIO27** |
+| SGP30 SDA | **GPIO22** | **GPIO22** |
+| SGP30 SCL | **GPIO27** | **GPIO21**（CN1；勿占 27=BL、32/33=触控） |
+| 供电 | USB 5V；传感器 **3.3V** | 同左 |

-接线：`VCC→3.3V`，`GND→GND`，`SDA→GPIO22`，`SCL→GPIO27`。
+接线（SGP30）：`VCC→3.3V`，`GND→GND`，再按上表接 SDA/SCL。

 ## 功能

@@ -30,21 +32,30 @@ ESP32 Cheap Yellow Display（ESP32-2432S028R）+ SGP30 + LVGL 空气质量仪表
 依赖 [PlatformIO](https://platformio.org/)。

 ```bash
-pio run -e cyd_28r -t upload
+pio run -e cyd_28r -t upload          # 2.8"
+pio run -e cyd_35r -t upload          # 3.5C
 pio device monitor -b 115200
 ```

 ### 预编译固件（随时刷，不必编译）

-已归档到 [`firmware/cyd_28r/`](firmware/cyd_28r/)（含 bootloader / partitions / app）：
+| 板型 | 目录 |
+|------|------|
+| 2.8" | [`firmware/cyd_28r/`](firmware/cyd_28r/) |
+| 3.5" | [`firmware/cyd_35r/`](firmware/cyd_35r/) |

 ```powershell
-cd firmware\cyd_28r
+cd firmware\cyd_28r   # 或 cyd_35r
 .\flash.ps1
 # 或 .\flash.ps1 -Port COM3
 ```

-说明见 [`firmware/README.md`](firmware/README.md)。源码更新后重新打包：`.\firmware\export_from_build.ps1`。
+说明见 [`firmware/README.md`](firmware/README.md)。重新打包：
+
+```powershell
+.\firmware\export_from_build.ps1            # 2.8
+.\firmware\export_from_build.ps1 -Env cyd_35r
+```

 ### 环境选择

@@ -53,6 +64,7 @@ cd firmware\cyd_28r
 | `cyd_28r` | 标准 ILI9341 CYD（默认） |
 | `cyd_28r_inv` | 颜色反相 / 发白 |
 | `cyd_28_st7789` | USB-C 双口 / ST7789 变体 |
+| `cyd_35r` | 3.5" ST7796 + GT911（BL=27，SGP30 SDA22/SCL21） |

 ## 项目结构

@@ -79,5 +91,6 @@ README.md                      # 本文档

 | 日期 | 说明 |
 |------|------|
+| 2026-10-25 | 按 CYD_PROJECT_GUIDE：3.5 修正 TFT_BL=27；SGP30 保持 SDA=22/SCL=21；GT911 INT 复位后改 INPUT；不动 2.8 |
 | 2026-10-18 | 初版：LVGL 空气质量仪表盘 + SGP30（SDA=GPIO22 / SCL=GPIO27），eCO2/TVOC 双表盘、质量条、趋势图、背光与 min/max |
 | 2026-10-18 | 初始化 Git；归档预编译固件到 `firmware/cyd_28r/`，附一键刷写脚本 |
--- a/firmware/README.md
+++ b/firmware/README.md
@@ -1,23 +1,25 @@
 # 预编译固件（可随时刷写）

-当前归档目录：[`cyd_28r/`](cyd_28r/)
+| 目录 | 板子 | SGP30 | 背光 |
+|------|------|-------|------|
+| [`cyd_28r/`](cyd_28r/) | ESP32-2432S028R（ILI9341） | SDA=22 / SCL=27 | GPIO21 |
+| [`cyd_35r/`](cyd_35r/) | ESP32-3248S035C（ST7796 + GT911） | SDA=22 / SCL=21 | GPIO27 |

-对应板子：**CYD ESP32-2432S028R**（ILI9341），SGP30 → SDA=GPIO22 / SCL=GPIO27。  
-版本信息见 [`cyd_28r/VERSION.txt`](cyd_28r/VERSION.txt)。
+版本信息见各目录 `VERSION.txt`。引脚约定见 [`../CYD_PROJECT_GUIDE.md`](../../CYD_PROJECT_GUIDE.md)。

 ## 直接刷写（无需重新编译）

 1. USB 连接板子  
-2. 在本目录执行：
+2. 进入对应目录执行：

 ```powershell
-cd firmware\cyd_28r
+cd firmware\cyd_28r   # 或 cyd_35r
 .\flash.ps1
 # 或指定端口
 .\flash.ps1 -Port COM3
 ```

-也可双击 / 运行 `flash.bat`。
+也可双击 / 运行 `flash.bat`（若有）。

 依赖其一即可：

@@ -40,7 +42,9 @@ esptool.py --chip esp32 --port COM3 --baud 921600 write_flash -z ^
 在仓库根目录：

 ```powershell
-.\firmware\export_from_build.ps1
+.\firmware\export_from_build.ps1                 # 2.8 -> cyd_28r
+.\firmware\export_from_build.ps1 -Env cyd_35r    # 3.5 -> cyd_35r
 # 仅复制、不编译：
 .\firmware\export_from_build.ps1 -SkipBuild
+.\firmware\export_from_build.ps1 -Env cyd_35r -SkipBuild
 ```
--- a/firmware/cyd_35r/VERSION.txt
+++ b/firmware/cyd_35r/VERSION.txt
@@ -0,0 +1,17 @@
+name: CYD sgp30test (cyd_35r)
+git: 1b2fe27
+date: 2026-10-25
+board: ESP32-3248S035 (ST7796 + GT911)
+sgp30: SDA=GPIO22 SCL=GPIO21
+tft_bl: GPIO27
+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    35AD57B34071317C3B1D3CF25B7F9E41C780D9134577A7229A113E8936BA3040
+  partitions.bin  0A8B5720E7B77FF11F1462458C3A509DEE79224E5279898F26D6A2E3AE0517B7
--- 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 +1,84 @@
+# Flash archived CYD SGP30 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 {
+  $pio = Get-Command pio -ErrorAction SilentlyContinue
+  if ($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 $tool) {
+  Write-Error "esptool not found. Install PlatformIO (`pio`) or: pip install esptool"
+}
+
+$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 +1,65 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="utf-8" />
+<title>AIR</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:#0A1018;color:#F2F5FA;font:12px/1.2 system-ui,sans-serif;
+    overflow:hidden;}
+  .hdr{display:flex;align-items:center;gap:8px;padding:4px 8px;height:24px}
+  .hdr b{font-size:14px}.up{color:#7E90A8}.sp{margin-left:auto;display:flex;gap:6px;align-items:center;color:#7E90A8}
+  .led{width:9px;height:9px;border-radius:50%;background:#4CAF7A}
+  .row{display:flex;gap:6px;padding:0 8px}
+  .panel{flex:1;height:118px;background:#121C2A;border:1px solid #1E2C40;border-radius:6px;padding:6px 8px;position:relative}
+  .cap{color:#7E90A8;font-size:11px}
+  .gauge{width:90px;height:90px;margin:4px auto 0;border-radius:50%;
+    background:conic-gradient(#4DA3FF 0 40%, #243247 0);
+    mask:radial-gradient(farthest-side,transparent 62%,#000 63%);
+    -webkit-mask:radial-gradient(farthest-side,transparent 62%,#000 63%)}
+  .panel.tvoc .gauge{background:conic-gradient(#B07CFF 0 28%, #243247 0)}
+  .val{position:absolute;left:0;right:0;top:44px;text-align:center;font-size:20px;font-weight:700;color:#4DA3FF}
+  .panel.tvoc .val{color:#B07CFF}
+  .unit{font-size:10px;color:#7E90A8}
+  .rng{position:absolute;left:0;right:0;bottom:6px;text-align:center;color:#7E90A8;font-size:11px}
+  .bot{margin:6px 8px 0;height:78px;background:#121C2A;border:1px solid #1E2C40;border-radius:6px;display:flex;gap:8px;padding:8px}
+  .info{width:96px}.ok{color:#4CAF7A;font-size:14px;font-weight:700}
+  .meta{margin-top:10px;color:#7E90A8;font-size:11px}
+  .chart{flex:1;background:#0E1622;border-radius:4px}
+  .chart svg{width:100%;height:100%}
+
+/* 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="hdr"><b>AIR</b><span class="up">up 03:10</span>
+    <span class="sp"><span>GOOD</span><span class="led"></span></span></div>
+  <div class="row">
+    <div class="panel"><div class="cap">eCO2</div><div class="gauge"></div>
+      <div class="val">612<span class="unit"> ppm</span></div><div class="rng">baseline</div></div>
+    <div class="panel tvoc"><div class="cap">TVOC</div><div class="gauge"></div>
+      <div class="val">84<span class="unit"> ppb</span></div><div class="rng">SGP30</div></div>
+  </div>
+  <div class="bot">
+    <div class="info"><div class="ok">FRESH</div>
+      <div class="meta">SDA22 · SCL27<br/>IAQ index OK</div></div>
+    <div class="chart"><svg viewBox="0 0 180 60" preserveAspectRatio="none">
+      <polyline fill="none" stroke="#4DA3FF" stroke-width="2"
+        points="0,35 30,32 60,30 90,28 120,33 150,29 180,27"/>
+      <polyline fill="none" stroke="#B07CFF" stroke-width="2"
+        points="0,48 30,46 60,44 90,45 120,42 150,43 180,41"/>
+    </svg></div>
+  </div>
+</div></div>
+
+
+</div>
+</body>
+</html>
--- a/firmware/cyd_35r/meta.json
+++ b/firmware/cyd_35r/meta.json
@@ -0,0 +1,15 @@
+{
+  "boardId": "esp32-3248s035",
+  "name": "CYD SGP30 air quality dashboard (3.5\")",
+  "summary": "eCO2 and TVOC air-quality gauges",
+  "description": "SGP30 on SDA=GPIO22 / SCL=GPIO21. TFT_BL=GPIO27. Dual arcs and IAQ status.",
+  "tags": [
+    "air",
+    "sgp30",
+    "eco2",
+    "tvoc"
+  ],
+  "media": {
+    "preview": "media/preview.html"
+  }
+}
--- a/firmware/cyd_35r/partitions.bin
+++ b/firmware/cyd_35r/partitions.bin
--- a/firmware/export_from_build.ps1
+++ b/firmware/export_from_build.ps1
@@ -23,11 +23,15 @@ if (-not $SkipBuild) {
 $src = Join-Path $root (".pio\build\" + $Env)
 if ($Env -eq "cyd_35r") {
  $dstName = "cyd_35r"
-  $boardLine = "board: ESP32-3248S035 (ST7796)"
+  $boardLine = "board: ESP32-3248S035 (ST7796 + GT911)"
+  $sgpLine = "sgp30: SDA=GPIO22 SCL=GPIO21"
+  $blLine = "tft_bl: GPIO27"
  $boardIdHint = "esp32-3248s035"
 } else {
  $dstName = "cyd_28r"
  $boardLine = "board: ESP32-2432S028R (ILI9341)"
+  $sgpLine = "sgp30: SDA=GPIO22 SCL=GPIO27"
+  $blLine = "tft_bl: GPIO21"
  $boardIdHint = "esp32-2432s028"
 }
 $dst = Join-Path $root ("firmware\" + $dstName)
@@ -54,6 +58,8 @@ $lines = @(
  "git: $git",
  "date: $date",
  $boardLine,
+  $sgpLine,
+  $blLine,
  "flash_size: 4MB",
  "offsets:",
  "  0x1000  bootloader.bin",
@@ -67,21 +73,5 @@ foreach ($h in $hashes) {
 }
 $lines | Set-Content -Encoding utf8 (Join-Path $dst "VERSION.txt")

-# Keep / refresh meta.json boardId for catalog filtering
-$metaPath = Join-Path $dst "meta.json"
-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\")"
-    }
-    $meta | ConvertTo-Json -Depth 8 | Set-Content -Encoding utf8 $metaPath
-  } catch {
-    Write-Host "meta.json update skipped: $_"
-  }
-} elseif ($Env -eq "cyd_35r") {
-  Write-Host "Note: add firmware/cyd_35r/meta.json with boardId=$boardIdHint for the web catalog"
-}

 Write-Host "Exported -> $dst (env=$Env git=$git)"
--- a/include/touch.h
+++ b/include/touch.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#include <lvgl.h>
+
+void touch_init();
+void touch_read_cb(lv_indev_t *indev, lv_indev_data_t *data);
--- a/platformio.ini
+++ b/platformio.ini
@@ -1,6 +1,5 @@
-; CYD ESP32-2432S028R â€?LVGL SGP30 ç©ºæ°”è´¨é‡<C3A9>ä»ªè¡¨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

-; æ ‡å‡† CYD 2.8" ç”µé˜»å±?(ILI9341)
+; 标准 CYD 2.8" 电阻<EFBFBD>?(ILI9341)
 [env:cyd_28r]
 build_flags =
  ${env.build_flags}

-; é¢œè‰²å<EFBFBD><EFBFBD>ç›¸ç‰ˆæœ¬ï¼ˆè‹¥ç”»é<EFBFBD>¢è‰²å<EFBFBD><EFBFBD>/å<>‘ç™½å<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

--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,30 +1,26 @@
 /**
- * CYD ESP32-2432S028R — LVGL SGP30 空气质量仪表盘
- * SGP30 SDA -> GPIO22, SCL -> GPIO27
+ * CYD LVGL SGP30 空气质量仪表盘
+ * 2.8 (2432S028R): SDA=22 SCL=27, TFT_BL=21
+ * 3.5C (3248S035C): SDA=22 SCL=21 (CN1), TFT_BL=27 — see ../CYD_PROJECT_GUIDE.md
 */

 #include <Arduino.h>
 #include <Wire.h>
 #include <lvgl.h>
 #include <TFT_eSPI.h>
-#include <XPT2046_Touchscreen.h>
 #include <Adafruit_SGP30.h>
 #include <math.h>
+#include "touch.h"

 #define I2C_SDA 22
-#define I2C_SCL 27
 #if defined(CYD_BOARD_3248S035)
+#define I2C_SCL 21
 #define TFT_BL_PIN 27
 #else
+#define I2C_SCL 27
 #define TFT_BL_PIN 21
 #endif

-#define XPT2046_IRQ 36
-#define XPT2046_MOSI 32
-#define XPT2046_MISO 39
-#define XPT2046_CLK 25
-#define XPT2046_CS 33
-
 #if defined(CYD_BOARD_3248S035)
 #define SCREEN_WIDTH 480
 #define SCREEN_HEIGHT 320
@@ -37,7 +33,11 @@
 #define EMA_ALPHA 0.35f
 #define HISTORY_LEN 48
 #define WARMUP_SEC 15
+#if defined(CYD_BOARD_3248S035)
+#define DRAW_BUF_SIZE (SCREEN_WIDTH * SCREEN_HEIGHT / 20 * (LV_COLOR_DEPTH / 8))
+#else
 #define DRAW_BUF_SIZE (SCREEN_WIDTH * SCREEN_HEIGHT / 10 * (LV_COLOR_DEPTH / 8))
+#endif

 /* Gauge display clamps (arc range) */
 #define ECO2_ARC_MAX 2000
@@ -82,8 +82,6 @@ static const lv_color_t COL_BAD = lv_color_hex(0xE05A5A);
 static const lv_color_t COL_ARC_BG = lv_color_hex(0x243247);
 static const lv_color_t COL_CHART_BG = lv_color_hex(0x0E1622);

-SPIClass touchscreenSPI = SPIClass(VSPI);
-XPT2046_Touchscreen touchscreen(XPT2046_CS, XPT2046_IRQ);
 Adafruit_SGP30 sgp;

 static uint32_t draw_buf[DRAW_BUF_SIZE / 4];
@@ -212,32 +210,26 @@ static void reset_minmax(void) {
 }

 static void touchscreen_read(lv_indev_t *indev, lv_indev_data_t *data) {
-  LV_UNUSED(indev);
  static bool was_pressed = false;
  static uint32_t press_ms = 0;

-  if (touchscreen.tirqTouched() && touchscreen.touched()) {
-    TS_Point p = touchscreen.getPoint();
-    data->point.x = map(p.y, 240, 3800, 1, SCREEN_WIDTH);
-    data->point.y = map(p.x, 200, 3700, SCREEN_HEIGHT, 1);
-    data->state = LV_INDEV_STATE_PRESSED;
+  touch_read_cb(indev, data);
+
+  if (data->state == LV_INDEV_STATE_PRESSED) {
    if (!was_pressed) {
      was_pressed = true;
      press_ms = millis();
    }
-  } else {
-    data->state = LV_INDEV_STATE_RELEASED;
-    if (was_pressed) {
-      was_pressed = false;
-      uint32_t held = millis() - press_ms;
-      if (held >= 700) {
-        reset_minmax();
-      } else if (held < 400) {
-        set_backlight((bright_level + 1) & 0x03);
-        char buf[20];
-        lv_snprintf(buf, sizeof(buf), "brightness %u/3", (unsigned)bright_level);
-        show_hint(buf, 900);
-      }
+  } else if (was_pressed) {
+    was_pressed = false;
+    uint32_t held = millis() - press_ms;
+    if (held >= 700) {
+      reset_minmax();
+    } else if (held < 400) {
+      set_backlight((bright_level + 1) & 0x03);
+      char buf[20];
+      lv_snprintf(buf, sizeof(buf), "brightness %u/3", (unsigned)bright_level);
+      show_hint(buf, 900);
    }
  }
 }
@@ -601,15 +593,19 @@ void setup() {
  set_backlight(2);

  Serial.println("CYD LVGL SGP30 Air Quality Dashboard");
-  Serial.printf("LVGL %d.%d.%d  SDA=GPIO%d SCL=GPIO%d\n",
+  Serial.printf("LVGL %d.%d.%d  SDA=GPIO%d SCL=GPIO%d  BL=GPIO%d\n",
                lv_version_major(), lv_version_minor(), lv_version_patch(),
-                I2C_SDA, I2C_SCL);
+                I2C_SDA, I2C_SCL, TFT_BL_PIN);
+
+  /* Touch first on 3.5: GT911 may pulse INT(=21); release before SGP30 Wire. */
+  touch_init();

  Wire.begin(I2C_SDA, I2C_SCL);
  Wire.setClock(100000);

  if (!sgp.begin()) {
-    Serial.println("SGP30 not found — check wiring (SDA22/SCL27)");
+    Serial.printf("SGP30 not found — check wiring (SDA%d/SCL%d)\n",
+                  I2C_SDA, I2C_SCL);
  } else {
    Serial.printf("SGP30 OK  serial 0x%04X%04X\n",
                  sgp.serialnumber[0], sgp.serialnumber[1]);
@@ -618,11 +614,7 @@ void setup() {

  lv_init();

-  touchscreenSPI.begin(XPT2046_CLK, XPT2046_MISO, XPT2046_MOSI, XPT2046_CS);
-  touchscreen.begin(touchscreenSPI);
-  touchscreen.setRotation(2);
-
-  #if defined(CYD_BOARD_3248S035)
+#if defined(CYD_BOARD_3248S035)
  lv_display_t *disp = lv_tft_espi_create(320, 480, draw_buf, sizeof(draw_buf));
 #else
  lv_display_t *disp = lv_tft_espi_create(240, 320, draw_buf, sizeof(draw_buf));
@@ -632,6 +624,7 @@ void setup() {
  lv_indev_t *indev = lv_indev_create();
  lv_indev_set_type(indev, LV_INDEV_TYPE_POINTER);
  lv_indev_set_read_cb(indev, touchscreen_read);
+  lv_indev_set_display(indev, disp);

  create_ui();
  delay(200);
--- a/src/touch.cpp
+++ b/src/touch.cpp
@@ -0,0 +1,193 @@
+#include "touch.h"
+
+#include <Arduino.h>
+
+/**
+ * 2.8": XPT2046 resistive SoftSPI bus (CS33).
+ * 3.5C (3248S035C): GT911 capacitive on Wire1 SDA33/SCL32/INT21/RST25.
+ * Feed coords are always native panel 320x480 for LVGL ROTATION_270.
+ * Wire1 leaves Wire free for SGP30 (3.5: SDA22/SCL21; TFT_BL=27).
+ */
+
+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)
+
+#include <Wire.h>
+
+/* Native panel size — not UI landscape SCREEN_* (480x320). */
+static constexpr int16_t PANEL_W = 320;
+static constexpr int16_t PANEL_H = 480;
+
+#define CYD_GT911_SDA 33
+#define CYD_GT911_SCL 32
+#define CYD_GT911_INT 21
+#define CYD_GT911_RST 25
+
+/* 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) {
+  Wire1.beginTransmission(s_gt_addr);
+  Wire1.write((uint8_t)(reg >> 8));
+  Wire1.write((uint8_t)(reg & 0xFF));
+  Wire1.write(val);
+  return Wire1.endTransmission() == 0;
+}
+
+static bool gt_read(uint16_t reg, uint8_t *buf, uint8_t len) {
+  Wire1.beginTransmission(s_gt_addr);
+  Wire1.write((uint8_t)(reg >> 8));
+  Wire1.write((uint8_t)(reg & 0xFF));
+  if (Wire1.endTransmission(false) != 0) {
+    return false;
+  }
+  const uint8_t n = Wire1.requestFrom(s_gt_addr, len);
+  if (n != len) {
+    return false;
+  }
+  for (uint8_t i = 0; i < len; i++) {
+    buf[i] = Wire1.read();
+  }
+  return true;
+}
+
+static bool gt_probe(uint8_t addr) {
+  Wire1.beginTransmission(addr);
+  return Wire1.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 — release INT(21) as input (may share SCL for SGP30). */
+  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 Wire1");
+  Wire1.begin(CYD_GT911_SDA, CYD_GT911_SCL);
+  Wire1.setClock(100000);
+#if defined(WIRE_HAS_TIMEOUT) || defined(ESP32)
+  Wire1.setTimeOut(50);
+#endif
+
+  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\n", CYD_GT911_SDA,
+                CYD_GT911_SCL, CYD_GT911_INT, CYD_GT911_RST);
+}
+
+void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
+  uint8_t info = 0;
+
+  if (!gt_read(GT_POINT_INFO, &info, 1)) {
+    data->state = LV_INDEV_STATE_RELEASED;
+    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;
+    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;
+    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. UI ≈ (H-1-raw_y, raw_x). */
+  const int16_t nx = clampi(raw_x, 0, PANEL_W - 1);
+  const int16_t ny = clampi(raw_y, 0, PANEL_H - 1);
+  data->point.x = (int16_t)((PANEL_W - 1) - nx);
+  data->point.y = (int16_t)((PANEL_H - 1) - ny);
+  data->state = LV_INDEV_STATE_PRESSED;
+}
+
+#else
+
+#include <SPI.h>
+#include <XPT2046_Touchscreen.h>
+
+#define XPT2046_IRQ 36
+#define XPT2046_MOSI 32
+#define XPT2046_MISO 39
+#define XPT2046_CLK 25
+#define XPT2046_CS 33
+
+/* 2.8 UI landscape feed (unchanged from prior main.cpp). */
+static constexpr int16_t UI_W = 320;
+static constexpr int16_t UI_H = 240;
+
+static SPIClass touchscreenSPI = SPIClass(VSPI);
+static XPT2046_Touchscreen touchscreen(XPT2046_CS, XPT2046_IRQ);
+
+void touch_init() {
+  touchscreenSPI.begin(XPT2046_CLK, XPT2046_MISO, XPT2046_MOSI, XPT2046_CS);
+  touchscreen.begin(touchscreenSPI);
+  touchscreen.setRotation(2);
+  Serial.println("Touch: XPT2046 resistive (2.8)");
+}
+
+void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
+  if (touchscreen.tirqTouched() && touchscreen.touched()) {
+    TS_Point p = touchscreen.getPoint();
+    data->point.x = map(p.y, 240, 3800, 1, UI_W);
+    data->point.y = map(p.x, 200, 3700, UI_H, 1);
+    data->state = LV_INDEV_STATE_PRESSED;
+  } else {
+    data->state = LV_INDEV_STATE_RELEASED;
+  }
+}
+
+#endif