diff --git a/firmware/export_from_build.ps1 b/firmware/export_from_build.ps1
index 6a233a8..7ea8e8a 100644
--- a/firmware/export_from_build.ps1
+++ b/firmware/export_from_build.ps1
@@ -1,9 +1,13 @@
-# Rebuild (optional) and refresh firmware/cyd from PlatformIO build output.
-# Usage:
-#   .\firmware\export_from_build.ps1
-#   .\firmware\export_from_build.ps1 -SkipBuild
+# Export firmware bins from PlatformIO build.
+# Default: 2.8" (cyd -> firmware/cyd)
+# 3.5":    .\firmware\export_from_build.ps1 -Env cyd_35r
+#          (only after: pio run -e cyd_35r)
 
-param([switch]$SkipBuild)
+param(
+  [switch]$SkipBuild,
+  [ValidateSet("cyd", "cyd_35r")]
+  [string]$Env = "cyd"
+)
 
 $ErrorActionPreference = "Stop"
 $root = Split-Path -Parent (Split-Path -Parent $MyInvocation.MyCommand.Path)
@@ -12,17 +16,26 @@ Set-Location $root
 $env:Path = "C:\Users\dsx2016\AppData\Local\Programs\Python\Python312\Scripts;" + $env:Path
 
 if (-not $SkipBuild) {
-  pio run -e cyd
+  pio run -e $Env
   if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
 }
 
-$src = Join-Path $root ".pio\build\cyd"
-$dst = Join-Path $root "firmware\cyd"
+$src = Join-Path $root (".pio\build\" + $Env)
+if ($Env -eq "cyd_35r") {
+  $dstName = "cyd_35r"
+  $boardLine = "board: ESP32-3248S035 (ST7796)"
+  $boardIdHint = "esp32-3248s035"
+} else {
+  $dstName = "cyd"
+  $boardLine = "board: ESP32-2432S028R (ILI9341)"
+  $boardIdHint = "esp32-2432s028"
+}
+$dst = Join-Path $root ("firmware\" + $dstName)
 New-Item -ItemType Directory -Force -Path $dst | Out-Null
 
 foreach ($f in @("bootloader.bin", "partitions.bin", "firmware.bin")) {
   $p = Join-Path $src $f
-  if (-not (Test-Path $p)) { Write-Error "Missing build artifact: $p" }
+  if (-not (Test-Path $p)) { Write-Error "Missing build artifact: $p — build with: pio run -e $Env" }
   Copy-Item $p $dst -Force
 }
 
@@ -32,17 +45,15 @@ if (-not (Test-Path $bootApp)) {
 }
 Copy-Item $bootApp (Join-Path $dst "boot_app0.bin") -Force
 
-# Keep flash scripts if already present
 $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
 $lines = @(
-  "name: CYD Photo album (cyd)",
+  "name: CYD phtotest ($dstName)",
   "git: $git",
   "date: $date",
-  "board: ESP32-2432S028R (ILI9341)",
-  "features: jpg/png/gif album, SoftSPI touch, TF card",
+  $boardLine,
   "flash_size: 4MB",
   "offsets:",
   "  0x1000  bootloader.bin",
@@ -55,4 +66,22 @@ foreach ($h in $hashes) {
   $lines += ("  {0,-15} {1}" -f (Split-Path $h.Path -Leaf), $h.Hash)
 }
 $lines | Set-Content -Encoding utf8 (Join-Path $dst "VERSION.txt")
-Write-Host "Exported -> $dst (git $git)"
+
+# Keep / refresh meta.json boardId for catalog filtering
+$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)"
diff --git a/include/pins.h b/include/pins.h
index 44adc4c..27e2294 100644
--- a/include/pins.h
+++ b/include/pins.h
@@ -1,16 +1,20 @@
 #pragma once
 
-// CYD ESP32-2432S028R
+// Board pins — 2.8" default; 3.5" when CYD_BOARD_3248S035 is set (env:cyd_35r)
 
+#if defined(CYD_BOARD_3248S035)
+#define TFT_BL_PIN 27
+#define SCREEN_WIDTH  320
+#define SCREEN_HEIGHT 480
+#define UI_HOR_RES    480
+#define UI_VER_RES    320
+#else
 #define TFT_BL_PIN 21
-
-// TF / microSD (VSPI；触摸用 SoftSPI，不抢总线)
-#define SD_MISO 19
-#define SD_MOSI 23
-#define SD_SCK  18
-#define SD_CS   5
-
-#define SPEAKER_PIN 26
+#define SCREEN_WIDTH  240
+#define SCREEN_HEIGHT 320
+#define UI_HOR_RES    320
+#define UI_VER_RES    240
+#endif
 
 #define CYD_TOUCH_IRQ  36
 #define CYD_TOUCH_MOSI 32
@@ -18,7 +22,15 @@
 #define CYD_TOUCH_CLK  25
 #define CYD_TOUCH_CS   33
 
-#define SCREEN_WIDTH  240
-#define SCREEN_HEIGHT 320
-#define UI_HOR_RES    320
-#define UI_VER_RES    240
+/* Map 320x240 design coordinates onto the active UI resolution (identity on 2.8"). */
+#define UX(x) ((int)(((long)(x) * (UI_HOR_RES)) / 320))
+#define UY(y) ((int)(((long)(y) * (UI_VER_RES)) / 240))
+#define UW(w) UX(w)
+#define UH(h) UY(h)
+
+
+#define SD_MISO 19
+#define SD_MOSI 23
+#define SD_SCK  18
+#define SD_CS   5
+#define SPEAKER_PIN 26
diff --git a/platformio.ini b/platformio.ini
index 819730e..47b34ce 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -57,3 +57,20 @@ build_flags =
   -I${PROJECT_DIR}/include
 
 extra_scripts = pre:copy_lv_conf.py
+
+; Optional 3.5" CYD ESP32-3248S035 (ST7796 resistive). Default remains [env:cyd].
+; Build: pio run -e cyd_35r
+[env:cyd_35r]
+extends = env:cyd
+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
+
diff --git a/src/ui.cpp b/src/ui.cpp
index b0e8a39..abee735 100644
--- a/src/ui.cpp
+++ b/src/ui.cpp
@@ -90,7 +90,7 @@ static void show_current() {
     lv_image_set_pivot(img_photo, 0, 0);
     lv_image_set_inner_align(img_photo, LV_IMAGE_ALIGN_STRETCH);
     lv_obj_set_size(img_photo, UI_HOR_RES, UI_VER_RES);
-    lv_obj_align(img_photo, LV_ALIGN_TOP_LEFT, 0, 0);
+    lv_obj_align(img_photo, LV_ALIGN_TOP_LEFT, UX(0), UY(0));
 
     const lv_image_dsc_t *dsc = photo_view_dsc();
     if (ok && dsc) {
@@ -183,7 +183,7 @@ void ui_create() {
   // Full-screen tap zones (behind chrome)
   lv_obj_t *tap = lv_obj_create(scr);
   lv_obj_set_size(tap, UI_HOR_RES, UI_VER_RES);
-  lv_obj_set_pos(tap, 0, 0);
+  lv_obj_set_pos(tap, UX(0), UY(0));
   lv_obj_set_style_bg_opa(tap, LV_OPA_TRANSP, 0);
   lv_obj_set_style_border_width(tap, 0, 0);
   lv_obj_set_style_pad_all(tap, 0, 0);
@@ -193,7 +193,7 @@ void ui_create() {
 
   img_photo = lv_image_create(scr);
   lv_obj_set_size(img_photo, UI_HOR_RES, UI_VER_RES);
-  lv_obj_align(img_photo, LV_ALIGN_TOP_LEFT, 0, 0);
+  lv_obj_align(img_photo, LV_ALIGN_TOP_LEFT, UX(0), UY(0));
   lv_image_set_scale(img_photo, LV_SCALE_NONE);
   lv_image_set_inner_align(img_photo, LV_IMAGE_ALIGN_STRETCH);
   lv_obj_set_style_bg_color(img_photo, lv_color_hex(0x000000), 0);
@@ -203,7 +203,7 @@ void ui_create() {
   // Top bar
   lv_obj_t *top = lv_obj_create(scr);
   lv_obj_set_size(top, UI_HOR_RES, 28);
-  lv_obj_set_pos(top, 0, 0);
+  lv_obj_set_pos(top, UX(0), UY(0));
   lv_obj_set_style_bg_color(top, lv_color_hex(COL_BG), 0);
   lv_obj_set_style_bg_opa(top, LV_OPA_80, 0);
   lv_obj_set_style_border_width(top, 0, 0);
@@ -216,19 +216,19 @@ void ui_create() {
   lv_label_set_text(lbl_title, "ALBUM");
   lv_obj_set_style_text_font(lbl_title, &lv_font_montserrat_16, 0);
   lv_obj_set_style_text_color(lbl_title, lv_color_hex(COL_ACCENT), 0);
-  lv_obj_set_pos(lbl_title, 8, 5);
+  lv_obj_set_pos(lbl_title, UX(8), UY(5));
 
   lbl_index = lv_label_create(top);
   lv_label_set_text(lbl_index, "0/0");
   lv_obj_set_style_text_font(lbl_index, &lv_font_montserrat_14, 0);
   lv_obj_set_style_text_color(lbl_index, lv_color_hex(COL_INK), 0);
-  lv_obj_align(lbl_index, LV_ALIGN_TOP_MID, 0, 6);
+  lv_obj_align(lbl_index, LV_ALIGN_TOP_MID, UX(0), UY(6));
 
   lbl_chip = lv_label_create(top);
   lv_label_set_text(lbl_chip, "-");
   lv_obj_set_style_text_font(lbl_chip, &lv_font_montserrat_14, 0);
   lv_obj_set_style_text_color(lbl_chip, lv_color_hex(COL_MUTED), 0);
-  lv_obj_align(lbl_chip, LV_ALIGN_TOP_RIGHT, -8, 6);
+  lv_obj_align(lbl_chip, LV_ALIGN_TOP_RIGHT, UX(-8), UY(6));
 
   // Bottom bar
   lv_obj_t *bot = lv_obj_create(scr);
@@ -242,8 +242,8 @@ void ui_create() {
   lv_obj_clear_flag(bot, LV_OBJ_FLAG_SCROLLABLE);
 
   btn_prev = lv_button_create(bot);
-  lv_obj_set_pos(btn_prev, 8, 6);
-  lv_obj_set_size(btn_prev, 56, 28);
+  lv_obj_set_pos(btn_prev, UX(8), UY(6));
+  lv_obj_set_size(btn_prev, UW(56), UH(28));
   lv_obj_add_flag(btn_prev, LV_OBJ_FLAG_CLICKABLE);
   lv_obj_add_event_cb(btn_prev, on_prev, LV_EVENT_CLICKED, nullptr);
   style_btn(btn_prev, COL_BTN);
@@ -255,7 +255,7 @@ void ui_create() {
 
   btn_next = lv_button_create(bot);
   lv_obj_set_pos(btn_next, UI_HOR_RES - 64, 6);
-  lv_obj_set_size(btn_next, 56, 28);
+  lv_obj_set_size(btn_next, UW(56), UH(28));
   lv_obj_add_flag(btn_next, LV_OBJ_FLAG_CLICKABLE);
   lv_obj_add_event_cb(btn_next, on_next, LV_EVENT_CLICKED, nullptr);
   style_btn(btn_next, COL_BTN_HI);
@@ -271,13 +271,13 @@ void ui_create() {
   lv_obj_set_width(lbl_name, UI_HOR_RES - 140);
   lv_obj_set_style_text_font(lbl_name, &lv_font_montserrat_14, 0);
   lv_obj_set_style_text_color(lbl_name, lv_color_hex(COL_INK), 0);
-  lv_obj_align(lbl_name, LV_ALIGN_TOP_MID, 0, 4);
+  lv_obj_align(lbl_name, LV_ALIGN_TOP_MID, UX(0), UY(4));
 
   lbl_hint = lv_label_create(bot);
   lv_label_set_text(lbl_hint, "Tap left/right");
   lv_obj_set_style_text_font(lbl_hint, &lv_font_montserrat_14, 0);
   lv_obj_set_style_text_color(lbl_hint, lv_color_hex(COL_MUTED), 0);
-  lv_obj_align(lbl_hint, LV_ALIGN_TOP_MID, 0, 20);
+  lv_obj_align(lbl_hint, LV_ALIGN_TOP_MID, UX(0), UY(20));
 
   // Raise bars / buttons above tap target for hit testing
   lv_obj_move_foreground(top);