Add connect to Wifi and File Manager Webserver (#41)

## Summary - **What is the goal of this PR?** Implements wireless EPUB file management via a built-in web server, enabling users to upload, browse, organize, and delete EPUB files from any device on the same WiFi network without needing a computer cable connection. - **What changes are included?** - **New Web Server** ([`CrossPointWebServer.cpp`](src/CrossPointWebServer.cpp), [`CrossPointWebServer.h`](src/CrossPointWebServer.h)): - HTTP server on port 80 with a responsive HTML/CSS interface - Home page showing device status (version, IP, free memory) - File Manager with folder navigation and breadcrumb support - EPUB file upload with progress tracking - Folder creation and file/folder deletion - XSS protection via HTML escaping - Hidden system folders (`.` prefixed, "System Volume Information", "XTCache") - **WiFi Screen** ([`WifiScreen.cpp`](src/screens/WifiScreen.cpp), [`WifiScreen.h`](src/screens/WifiScreen.h)): - Network scanning with signal strength indicators - Visual indicators for encrypted (`*`) and saved (`+`) networks - State machine managing: scanning, network selection, password entry, connecting, save/forget prompts - 15-second connection timeout handling - Integration with web server (starts on connect, stops on exit) - **WiFi Credential Storage** ([`WifiCredentialStore.cpp`](src/WifiCredentialStore.cpp), [`WifiCredentialStore.h`](src/WifiCredentialStore.h)): - Persistent storage in `/sd/.crosspoint/wifi.bin` - XOR obfuscation for stored passwords (basic protection against casual reading) - Up to 8 saved networks with add/remove/update operations - **On-Screen Keyboard** ([`OnScreenKeyboard.cpp`](src/screens/OnScreenKeyboard.cpp), [`OnScreenKeyboard.h`](src/screens/OnScreenKeyboard.h)): - Reusable QWERTY keyboard component with shift support - Special keys: Shift, Space, Backspace, Done - Support for password masking mode - **Settings Screen Integration** ([`SettingsScreen.h`](src/screens/SettingsScreen.h)): - Added WiFi action to navigate to the new WiFi screen - **Documentation** ([`docs/webserver.md`](docs/webserver.md)): - Comprehensive user guide covering WiFi setup, web interface usage, file management, troubleshooting, and security notes - See this for more screenshots! - Working "displays the right way in GitHub" on my repo: https://github.com/olearycrew/crosspoint-reader/blob/feature/connect-to-wifi/docs/webserver.md **Video demo** https://github.com/user-attachments/assets/283e32dc-2d9f-4ae2-848e-01f41166a731 ## Additional Context - **Security considerations**: The web server has no authentication—anyone on the same WiFi network can access files. This is documented as a limitation, recommending use only on trusted private networks. Password obfuscation in the credential store is XOR-based, not cryptographically secure. - **Memory implications**: The web server and WiFi stack consume significant memory. The implementation properly cleans up (stops server, disconnects WiFi, sets `WIFI_OFF` mode) when exiting the WiFi screen to free resources. - **Async operations**: Network scanning and connection use async patterns with FreeRTOS tasks to prevent blocking the UI. The display task handles rendering on a dedicated thread with mutex protection. - **Browser compatibility**: The web interface uses standard HTML5/CSS3/JavaScript and is tested to work with all modern browsers on desktop and mobile. --------- Co-authored-by: Dave Allie <dave@daveallie.com>
2026-04-29 10:26:52 -07:00 · 2025-12-20 01:05:43 +11:00
parent cf6fec78dc
commit d41d539435
29 changed files with 3791 additions and 20 deletions
@@ -3,3 +3,4 @@
 .DS_Store
 .vscode
 lib/EpdFont/fontsrc
+*.generated.h
@@ -0,0 +1,272 @@
+# Web Server Guide
+
+This guide explains how to connect your CrossPoint Reader to WiFi and use the built-in web server to upload EPUB files from your computer or phone.
+
+## Overview
+
+CrossPoint Reader includes a built-in web server that allows you to:
+
+- Upload EPUB files wirelessly from any device on the same WiFi network
+- Browse and manage files on your device's SD card
+- Create folders to organize your ebooks
+- Delete files and folders
+
+## Prerequisites
+
+- Your CrossPoint Reader device
+- A WiFi network
+- A computer, phone, or tablet connected to the **same WiFi network**
+
+---
+
+## Step 1: Accessing the WiFi Screen
+
+1. From the main menu or file browser, navigate to the **Settings** screen
+2. Select the **WiFi** option
+3. The device will automatically start scanning for available networks
+
+---
+
+## Step 2: Connecting to WiFi
+
+### Viewing Available Networks
+
+Once the scan completes, you'll see a list of available WiFi networks with the following indicators:
+
+- **Signal strength bars** (`||||`, `|||`, `||`, `|`) - Shows connection quality
+- **`*` symbol** - Indicates the network is password-protected (encrypted)
+- **`+` symbol** - Indicates you have previously saved credentials for this network
+
+<img src="./images/wifi/wifi_networks.jpeg" height="500">
+
+### Selecting a Network
+
+1. Use the **Left/Right** (or **Volume Up/Down**) buttons to navigate through the network list
+2. Press **Confirm** to select the highlighted network
+
+### Entering Password (for encrypted networks)
+
+If the network requires a password:
+
+1. An on-screen keyboard will appear
+2. Use the navigation buttons to select characters
+3. Press **Confirm** to enter each character
+4. When complete, select the **Done** option on the keyboard
+
+<img src="./images/wifi/wifi_password.jpeg" height="500">
+
+**Note:** If you've previously connected to this network, the saved password will be used automatically.
+
+### Connection Process
+
+The device will display "Connecting..." while establishing the connection. This typically takes 5-10 seconds.
+
+### Saving Credentials
+
+If this is a new network, you'll be prompted to save the password:
+
+- Select **Yes** to save credentials for automatic connection next time (NOTE: These are stored in plaintext on the device's SD card. Do not use this for sensitive networks.)
+- Select **No** to connect without saving
+
+---
+
+## Step 3: Connection Success
+
+Once connected, the screen will display:
+
+- **Network name** (SSID)
+- **IP Address** (e.g., `192.168.1.102`)
+- **Web server URL** (e.g., `http://192.168.1.102/`)
+
+<img src="./images/wifi/wifi_connected.jpeg" height="500">
+
+**Important:** Make note of the IP address - you'll need this to access the web interface from your computer or phone.
+
+---
+
+## Step 4: Accessing the Web Interface
+
+### From a Computer
+
+1. Ensure your computer is connected to the **same WiFi network** as your CrossPoint Reader
+2. Open any web browser (Chrome is recommended)
+3. Type the IP address shown on your device into the browser's address bar
+   - Example: `http://192.168.1.102/`
+4. Press Enter
+
+### From a Phone or Tablet
+
+1. Ensure your phone/tablet is connected to the **same WiFi network** as your CrossPoint Reader
+2. Open your mobile browser (Safari, Chrome, etc.)
+3. Type the IP address into the address bar
+   - Example: `http://192.168.1.102/`
+4. Tap Go
+
+---
+
+## Step 5: Using the Web Interface
+
+### Home Page
+
+The home page displays:
+
+- Device status and version information
+- WiFi connection status
+- Current IP address
+- Available memory
+
+Navigation links:
+
+- **Home** - Returns to the status page
+- **File Manager** - Access file management features
+
+<img src="./images/wifi/webserver_homepage.png" width="600">
+
+### File Manager
+
+Click **File Manager** to access file management features.
+
+#### Browsing Files
+
+- The file manager displays all files and folders on your SD card
+- **Folders** are highlighted in yellow with a 📁 icon
+- **EPUB files** are highlighted in green with a 📗 icon
+- Click on a folder name to navigate into it
+- Use the breadcrumb navigation at the top to go back to parent folders
+
+<img src="./images/wifi/webserver_files.png" width="600">
+
+#### Uploading EPUB Files
+
+1. Click the **+ Add** button in the top-right corner
+2. Select **Upload eBook** from the dropdown menu
+3. Click **Choose File** and select an `.epub` file from your device
+4. Click **Upload**
+5. A progress bar will show the upload status
+6. The page will automatically refresh when the upload is complete
+
+**Note:** Only `.epub` files are accepted. Other file types will be rejected.
+
+<img src="./images/wifi/webserver_upload.png" width="600">
+
+#### Creating Folders
+
+1. Click the **+ Add** button in the top-right corner
+2. Select **New Folder** from the dropdown menu
+3. Enter a folder name (letters, numbers, underscores, and hyphens only)
+4. Click **Create Folder**
+
+This is useful for organizing your ebooks by genre, author, or series.
+
+#### Deleting Files and Folders
+
+1. Click the **🗑️** (trash) icon next to any file or folder
+2. Confirm the deletion in the popup dialog
+3. Click **Delete** to permanently remove the item
+
+**Warning:** Deletion is permanent and cannot be undone!
+
+**Note:** Folders must be empty before they can be deleted.
+
+---
+
+## Troubleshooting
+
+### Cannot See the Device on the Network
+
+**Problem:** Browser shows "Cannot connect" or "Site can't be reached"
+
+**Solutions:**
+
+1. Verify both devices are on the **same WiFi network**
+   - Check your computer/phone WiFi settings
+   - Confirm the CrossPoint Reader shows "Connected" status
+2. Double-check the IP address
+   - Make sure you typed it correctly
+   - Include `http://` at the beginning
+3. Try disabling VPN if you're using one
+4. Some networks have "client isolation" enabled - check with your network administrator
+
+### Connection Drops or Times Out
+
+**Problem:** WiFi connection is unstable
+
+**Solutions:**
+
+1. Move closer to the WiFi router
+2. Check signal strength on the device (should be at least `||` or better)
+3. Avoid interference from other devices
+4. Try a different WiFi network if available
+
+### Upload Fails
+
+**Problem:** File upload doesn't complete or shows an error
+
+**Solutions:**
+
+1. Ensure the file is a valid `.epub` file
+2. Check that the SD card has enough free space
+3. Try uploading a smaller file first to test
+4. Refresh the browser page and try again
+
+### Saved Password Not Working
+
+**Problem:** Device fails to connect with saved credentials
+
+**Solutions:**
+
+1. When connection fails, you'll be prompted to "Forget Network"
+2. Select **Yes** to remove the saved password
+3. Reconnect and enter the password again
+4. Choose to save the new password
+
+---
+
+## Security Notes
+
+- The web server runs on port 80 (standard HTTP)
+- **No authentication is required** - anyone on the same network can access the interface
+- The web server is only accessible while the WiFi screen shows "Connected"
+- The web server automatically stops when you exit the WiFi screen
+- For security, only use on trusted private networks
+
+---
+
+## Technical Details
+
+- **Supported WiFi:** 2.4GHz networks (802.11 b/g/n)
+- **Web Server Port:** 80 (HTTP)
+- **Maximum Upload Size:** Limited by available SD card space
+- **Supported File Format:** `.epub` only
+- **Browser Compatibility:** All modern browsers (Chrome, Firefox, Safari, Edge)
+
+---
+
+## Tips and Best Practices
+
+1. **Organize with folders** - Create folders before uploading to keep your library organized
+2. **Check signal strength** - Stronger signals (`|||` or `||||`) provide faster, more reliable uploads
+3. **Upload multiple files** - You can upload files one at a time; the page refreshes after each upload
+4. **Use descriptive names** - Name your folders clearly (e.g., "SciFi", "Mystery", "Non-Fiction")
+5. **Keep credentials saved** - Save your WiFi password for quick reconnection in the future
+6. **Exit when done** - Press **Back** to exit the WiFi screen and save battery
+
+---
+
+## Exiting WiFi Mode
+
+When you're finished uploading files:
+
+1. Press the **Back** button on your CrossPoint Reader
+2. The web server will automatically stop
+3. WiFi will disconnect to conserve battery
+4. You'll return to the previous screen
+
+Your uploaded files will be immediately available in the file browser!
+
+---
+
+## Related Documentation
+
+- [User Guide](../USER_GUIDE.md) - General device operation
+- [README](../README.md) - Project overview and features
@@ -31,6 +31,9 @@ board_build.flash_mode = dio
 board_build.flash_size = 16MB
 board_build.partitions = partitions.csv

+extra_scripts =
+  pre:scripts/build_html.py
+
 ; Libraries
 lib_deps =
  BatteryMonitor=symlink://open-x4-sdk/libs/hardware/BatteryMonitor
@@ -0,0 +1,51 @@
+import os
+import re
+
+SRC_DIR = "src"
+
+def minify_html(html: str) -> str:
+    # Tags where whitespace should be preserved
+    preserve_tags = ['pre', 'code', 'textarea', 'script', 'style']
+    preserve_regex = '|'.join(preserve_tags)
+
+    # Protect preserve blocks with placeholders
+    preserve_blocks = []
+    def preserve(match):
+        preserve_blocks.append(match.group(0))
+        return f"__PRESERVE_BLOCK_{len(preserve_blocks)-1}__"
+
+    html = re.sub(rf'<({preserve_regex})[\s\S]*?</\1>', preserve, html, flags=re.IGNORECASE)
+
+    # Remove HTML comments
+    html = re.sub(r'<!--.*?-->', '', html, flags=re.DOTALL)
+
+    # Collapse all whitespace between tags
+    html = re.sub(r'>\s+<', '><', html)
+
+    # Collapse multiple spaces inside tags
+    html = re.sub(r'\s+', ' ', html)
+
+    # Restore preserved blocks
+    for i, block in enumerate(preserve_blocks):
+        html = html.replace(f"__PRESERVE_BLOCK_{i}__", block)
+
+    return html.strip()
+
+for root, _, files in os.walk(SRC_DIR):
+    for file in files:
+        if file.endswith(".html"):
+            html_path = os.path.join(root, file)
+            with open(html_path, "r", encoding="utf-8") as f:
+                html_content = f.read()
+
+            # minified = regex.sub("\g<1>", html_content)
+            minified = minify_html(html_content)
+            base_name = f"{os.path.splitext(file)[0]}Html"
+            header_path = os.path.join(root, f"{base_name}.generated.h")
+
+            with open(header_path, "w", encoding="utf-8") as h:
+                h.write(f"// THIS FILE IS AUTOGENERATED, DO NOT EDIT MANUALLY\n\n")
+                h.write(f"#pragma once\n")
+                h.write(f'constexpr char {base_name}[] PROGMEM = R"rawliteral({minified})rawliteral";\n')
+
+            print(f"Generated: {header_path}")
@@ -0,0 +1,160 @@
+#include "WifiCredentialStore.h"
+
+#include <HardwareSerial.h>
+#include <SD.h>
+#include <Serialization.h>
+
+#include <fstream>
+
+// Initialize the static instance
+WifiCredentialStore WifiCredentialStore::instance;
+
+namespace {
+// File format version
+constexpr uint8_t WIFI_FILE_VERSION = 1;
+
+// WiFi credentials file path
+constexpr char WIFI_FILE[] = "/sd/.crosspoint/wifi.bin";
+
+// Obfuscation key - "CrossPoint" in ASCII
+// This is NOT cryptographic security, just prevents casual file reading
+constexpr uint8_t OBFUSCATION_KEY[] = {0x43, 0x72, 0x6F, 0x73, 0x73, 0x50, 0x6F, 0x69, 0x6E, 0x74};
+constexpr size_t KEY_LENGTH = sizeof(OBFUSCATION_KEY);
+}  // namespace
+
+void WifiCredentialStore::obfuscate(std::string& data) const {
+  Serial.printf("[%lu] [WCS] Obfuscating/deobfuscating %zu bytes\n", millis(), data.size());
+  for (size_t i = 0; i < data.size(); i++) {
+    data[i] ^= OBFUSCATION_KEY[i % KEY_LENGTH];
+  }
+}
+
+bool WifiCredentialStore::saveToFile() const {
+  // Make sure the directory exists
+  SD.mkdir("/.crosspoint");
+
+  std::ofstream file(WIFI_FILE, std::ios::binary);
+  if (!file) {
+    Serial.printf("[%lu] [WCS] Failed to open wifi.bin for writing\n", millis());
+    return false;
+  }
+
+  // Write header
+  serialization::writePod(file, WIFI_FILE_VERSION);
+  serialization::writePod(file, static_cast<uint8_t>(credentials.size()));
+
+  // Write each credential
+  for (const auto& cred : credentials) {
+    // Write SSID (plaintext - not sensitive)
+    serialization::writeString(file, cred.ssid);
+    Serial.printf("[%lu] [WCS] Saving SSID: %s, password length: %zu\n", millis(), cred.ssid.c_str(),
+                  cred.password.size());
+
+    // Write password (obfuscated)
+    std::string obfuscatedPwd = cred.password;
+    obfuscate(obfuscatedPwd);
+    serialization::writeString(file, obfuscatedPwd);
+  }
+
+  file.close();
+  Serial.printf("[%lu] [WCS] Saved %zu WiFi credentials to file\n", millis(), credentials.size());
+  return true;
+}
+
+bool WifiCredentialStore::loadFromFile() {
+  if (!SD.exists(WIFI_FILE + 3)) {  // +3 to skip "/sd" prefix
+    Serial.printf("[%lu] [WCS] WiFi credentials file does not exist\n", millis());
+    return false;
+  }
+
+  std::ifstream file(WIFI_FILE, std::ios::binary);
+  if (!file) {
+    Serial.printf("[%lu] [WCS] Failed to open wifi.bin for reading\n", millis());
+    return false;
+  }
+
+  // Read and verify version
+  uint8_t version;
+  serialization::readPod(file, version);
+  if (version != WIFI_FILE_VERSION) {
+    Serial.printf("[%lu] [WCS] Unknown file version: %u\n", millis(), version);
+    file.close();
+    return false;
+  }
+
+  // Read credential count
+  uint8_t count;
+  serialization::readPod(file, count);
+
+  // Read credentials
+  credentials.clear();
+  for (uint8_t i = 0; i < count && i < MAX_NETWORKS; i++) {
+    WifiCredential cred;
+
+    // Read SSID
+    serialization::readString(file, cred.ssid);
+
+    // Read and deobfuscate password
+    serialization::readString(file, cred.password);
+    Serial.printf("[%lu] [WCS] Loaded SSID: %s, obfuscated password length: %zu\n", millis(), cred.ssid.c_str(),
+                  cred.password.size());
+    obfuscate(cred.password);  // XOR is symmetric, so same function deobfuscates
+    Serial.printf("[%lu] [WCS] After deobfuscation, password length: %zu\n", millis(), cred.password.size());
+
+    credentials.push_back(cred);
+  }
+
+  file.close();
+  Serial.printf("[%lu] [WCS] Loaded %zu WiFi credentials from file\n", millis(), credentials.size());
+  return true;
+}
+
+bool WifiCredentialStore::addCredential(const std::string& ssid, const std::string& password) {
+  // Check if this SSID already exists and update it
+  for (auto& cred : credentials) {
+    if (cred.ssid == ssid) {
+      cred.password = password;
+      Serial.printf("[%lu] [WCS] Updated credentials for: %s\n", millis(), ssid.c_str());
+      return saveToFile();
+    }
+  }
+
+  // Check if we've reached the limit
+  if (credentials.size() >= MAX_NETWORKS) {
+    Serial.printf("[%lu] [WCS] Cannot add more networks, limit of %zu reached\n", millis(), MAX_NETWORKS);
+    return false;
+  }
+
+  // Add new credential
+  credentials.push_back({ssid, password});
+  Serial.printf("[%lu] [WCS] Added credentials for: %s\n", millis(), ssid.c_str());
+  return saveToFile();
+}
+
+bool WifiCredentialStore::removeCredential(const std::string& ssid) {
+  for (auto it = credentials.begin(); it != credentials.end(); ++it) {
+    if (it->ssid == ssid) {
+      credentials.erase(it);
+      Serial.printf("[%lu] [WCS] Removed credentials for: %s\n", millis(), ssid.c_str());
+      return saveToFile();
+    }
+  }
+  return false;  // Not found
+}
+
+const WifiCredential* WifiCredentialStore::findCredential(const std::string& ssid) const {
+  for (const auto& cred : credentials) {
+    if (cred.ssid == ssid) {
+      return &cred;
+    }
+  }
+  return nullptr;
+}
+
+bool WifiCredentialStore::hasSavedCredential(const std::string& ssid) const { return findCredential(ssid) != nullptr; }
+
+void WifiCredentialStore::clearAll() {
+  credentials.clear();
+  saveToFile();
+  Serial.printf("[%lu] [WCS] Cleared all WiFi credentials\n", millis());
+}
@@ -0,0 +1,56 @@
+#pragma once
+#include <string>
+#include <vector>
+
+struct WifiCredential {
+  std::string ssid;
+  std::string password;  // Stored obfuscated in file
+};
+
+/**
+ * Singleton class for storing WiFi credentials on the SD card.
+ * Credentials are stored in /sd/.crosspoint/wifi.bin with basic
+ * XOR obfuscation to prevent casual reading (not cryptographically secure).
+ */
+class WifiCredentialStore {
+ private:
+  static WifiCredentialStore instance;
+  std::vector<WifiCredential> credentials;
+
+  static constexpr size_t MAX_NETWORKS = 8;
+
+  // Private constructor for singleton
+  WifiCredentialStore() = default;
+
+  // XOR obfuscation (symmetric - same for encode/decode)
+  void obfuscate(std::string& data) const;
+
+ public:
+  // Delete copy constructor and assignment
+  WifiCredentialStore(const WifiCredentialStore&) = delete;
+  WifiCredentialStore& operator=(const WifiCredentialStore&) = delete;
+
+  // Get singleton instance
+  static WifiCredentialStore& getInstance() { return instance; }
+
+  // Save/load from SD card
+  bool saveToFile() const;
+  bool loadFromFile();
+
+  // Credential management
+  bool addCredential(const std::string& ssid, const std::string& password);
+  bool removeCredential(const std::string& ssid);
+  const WifiCredential* findCredential(const std::string& ssid) const;
+
+  // Get all stored credentials (for UI display)
+  const std::vector<WifiCredential>& getCredentials() const { return credentials; }
+
+  // Check if a network is saved
+  bool hasSavedCredential(const std::string& ssid) const;
+
+  // Clear all credentials
+  void clearAll();
+};
+
+// Helper macro to access credentials store
+#define WIFI_STORE WifiCredentialStore::getInstance()
@@ -15,4 +15,5 @@ class Activity {
  virtual void onEnter() {}
  virtual void onExit() {}
  virtual void loop() {}
+  virtual bool skipLoopDelay() { return false; }
 };
@@ -6,7 +6,7 @@
 #include "config.h"

 namespace {
-constexpr int menuItemCount = 2;
+constexpr int menuItemCount = 3;
 }

 void HomeActivity::taskTrampoline(void* param) {
@@ -51,6 +51,8 @@ void HomeActivity::loop() {
    if (selectorIndex == 0) {
      onReaderOpen();
    } else if (selectorIndex == 1) {
+      onFileTransferOpen();
+    } else if (selectorIndex == 2) {
      onSettingsOpen();
    }
  } else if (prevPressed) {
@@ -84,7 +86,8 @@ void HomeActivity::render() const {
  // Draw selection
  renderer.fillRect(0, 60 + selectorIndex * 30 + 2, pageWidth - 1, 30);
  renderer.drawText(UI_FONT_ID, 20, 60, "Read", selectorIndex != 0);
-  renderer.drawText(UI_FONT_ID, 20, 90, "Settings", selectorIndex != 1);
+  renderer.drawText(UI_FONT_ID, 20, 90, "File transfer", selectorIndex != 1);
+  renderer.drawText(UI_FONT_ID, 20, 120, "Settings", selectorIndex != 2);

  renderer.drawRect(25, pageHeight - 40, 106, 40);
  renderer.drawText(UI_FONT_ID, 25 + (105 - renderer.getTextWidth(UI_FONT_ID, "Back")) / 2, pageHeight - 35, "Back");
@@ -14,6 +14,7 @@ class HomeActivity final : public Activity {
  bool updateRequired = false;
  const std::function<void()> onReaderOpen;
  const std::function<void()> onSettingsOpen;
+  const std::function<void()> onFileTransferOpen;

  static void taskTrampoline(void* param);
  [[noreturn]] void displayTaskLoop();
@@ -21,8 +22,11 @@ class HomeActivity final : public Activity {

 public:
  explicit HomeActivity(GfxRenderer& renderer, InputManager& inputManager, const std::function<void()>& onReaderOpen,
-                        const std::function<void()>& onSettingsOpen)
-      : Activity(renderer, inputManager), onReaderOpen(onReaderOpen), onSettingsOpen(onSettingsOpen) {}
+                        const std::function<void()>& onSettingsOpen, const std::function<void()>& onFileTransferOpen)
+      : Activity(renderer, inputManager),
+        onReaderOpen(onReaderOpen),
+        onSettingsOpen(onSettingsOpen),
+        onFileTransferOpen(onFileTransferOpen) {}
  void onEnter() override;
  void onExit() override;
  void loop() override;
@@ -0,0 +1,243 @@
+#include "CrossPointWebServerActivity.h"
+
+#include <GfxRenderer.h>
+#include <WiFi.h>
+
+#include "config.h"
+
+void CrossPointWebServerActivity::taskTrampoline(void* param) {
+  auto* self = static_cast<CrossPointWebServerActivity*>(param);
+  self->displayTaskLoop();
+}
+
+void CrossPointWebServerActivity::onEnter() {
+  Serial.printf("[%lu] [WEBACT] ========== CrossPointWebServerActivity onEnter ==========\n", millis());
+  Serial.printf("[%lu] [WEBACT] [MEM] Free heap at onEnter: %d bytes\n", millis(), ESP.getFreeHeap());
+
+  renderingMutex = xSemaphoreCreateMutex();
+
+  // Reset state
+  state = WebServerActivityState::WIFI_SELECTION;
+  connectedIP.clear();
+  connectedSSID.clear();
+  lastHandleClientTime = 0;
+  updateRequired = true;
+
+  xTaskCreate(&CrossPointWebServerActivity::taskTrampoline, "WebServerActivityTask",
+              2048,               // Stack size
+              this,               // Parameters
+              1,                  // Priority
+              &displayTaskHandle  // Task handle
+  );
+
+  // Turn on WiFi immediately
+  Serial.printf("[%lu] [WEBACT] Turning on WiFi...\n", millis());
+  WiFi.mode(WIFI_STA);
+
+  // Launch WiFi selection subactivity
+  Serial.printf("[%lu] [WEBACT] Launching WifiSelectionActivity...\n", millis());
+  wifiSelection.reset(new WifiSelectionActivity(renderer, inputManager,
+                                                [this](bool connected) { onWifiSelectionComplete(connected); }));
+  wifiSelection->onEnter();
+}
+
+void CrossPointWebServerActivity::onExit() {
+  Serial.printf("[%lu] [WEBACT] ========== CrossPointWebServerActivity onExit START ==========\n", millis());
+  Serial.printf("[%lu] [WEBACT] [MEM] Free heap at onExit start: %d bytes\n", millis(), ESP.getFreeHeap());
+
+  state = WebServerActivityState::SHUTTING_DOWN;
+
+  // Stop the web server first (before disconnecting WiFi)
+  stopWebServer();
+
+  // Exit WiFi selection subactivity if still active
+  if (wifiSelection) {
+    Serial.printf("[%lu] [WEBACT] Exiting WifiSelectionActivity...\n", millis());
+    wifiSelection->onExit();
+    wifiSelection.reset();
+    Serial.printf("[%lu] [WEBACT] WifiSelectionActivity exited\n", millis());
+  }
+
+  // CRITICAL: Wait for LWIP stack to flush any pending packets
+  Serial.printf("[%lu] [WEBACT] Waiting 500ms for network stack to flush pending packets...\n", millis());
+  delay(500);
+
+  // Disconnect WiFi gracefully
+  Serial.printf("[%lu] [WEBACT] Disconnecting WiFi (graceful)...\n", millis());
+  WiFi.disconnect(false);  // false = don't erase credentials, send disconnect frame
+  delay(100);              // Allow disconnect frame to be sent
+
+  Serial.printf("[%lu] [WEBACT] Setting WiFi mode OFF...\n", millis());
+  WiFi.mode(WIFI_OFF);
+  delay(100);  // Allow WiFi hardware to fully power down
+
+  Serial.printf("[%lu] [WEBACT] [MEM] Free heap after WiFi disconnect: %d bytes\n", millis(), ESP.getFreeHeap());
+
+  // Acquire mutex before deleting task
+  Serial.printf("[%lu] [WEBACT] Acquiring rendering mutex before task deletion...\n", millis());
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+
+  // Delete the display task
+  Serial.printf("[%lu] [WEBACT] Deleting display task...\n", millis());
+  if (displayTaskHandle) {
+    vTaskDelete(displayTaskHandle);
+    displayTaskHandle = nullptr;
+    Serial.printf("[%lu] [WEBACT] Display task deleted\n", millis());
+  }
+
+  // Delete the mutex
+  Serial.printf("[%lu] [WEBACT] Deleting mutex...\n", millis());
+  vSemaphoreDelete(renderingMutex);
+  renderingMutex = nullptr;
+  Serial.printf("[%lu] [WEBACT] Mutex deleted\n", millis());
+
+  Serial.printf("[%lu] [WEBACT] [MEM] Free heap at onExit end: %d bytes\n", millis(), ESP.getFreeHeap());
+  Serial.printf("[%lu] [WEBACT] ========== CrossPointWebServerActivity onExit COMPLETE ==========\n", millis());
+}
+
+void CrossPointWebServerActivity::onWifiSelectionComplete(bool connected) {
+  Serial.printf("[%lu] [WEBACT] WifiSelectionActivity completed, connected=%d\n", millis(), connected);
+
+  if (connected) {
+    // Get connection info before exiting subactivity
+    connectedIP = wifiSelection->getConnectedIP();
+    connectedSSID = WiFi.SSID().c_str();
+
+    // Exit the wifi selection subactivity
+    wifiSelection->onExit();
+    wifiSelection.reset();
+
+    // Start the web server
+    startWebServer();
+  } else {
+    // User cancelled - go back
+    onGoBack();
+  }
+}
+
+void CrossPointWebServerActivity::startWebServer() {
+  Serial.printf("[%lu] [WEBACT] Starting web server...\n", millis());
+
+  // Create the web server instance
+  webServer.reset(new CrossPointWebServer());
+  webServer->begin();
+
+  if (webServer->isRunning()) {
+    state = WebServerActivityState::SERVER_RUNNING;
+    Serial.printf("[%lu] [WEBACT] Web server started successfully\n", millis());
+
+    // Force an immediate render since we're transitioning from a subactivity
+    // that had its own rendering task. We need to make sure our display is shown.
+    xSemaphoreTake(renderingMutex, portMAX_DELAY);
+    render();
+    xSemaphoreGive(renderingMutex);
+    Serial.printf("[%lu] [WEBACT] Rendered File Transfer screen\n", millis());
+  } else {
+    Serial.printf("[%lu] [WEBACT] ERROR: Failed to start web server!\n", millis());
+    webServer.reset();
+    // Go back on error
+    onGoBack();
+  }
+}
+
+void CrossPointWebServerActivity::stopWebServer() {
+  if (webServer && webServer->isRunning()) {
+    Serial.printf("[%lu] [WEBACT] Stopping web server...\n", millis());
+    webServer->stop();
+    Serial.printf("[%lu] [WEBACT] Web server stopped\n", millis());
+  }
+  webServer.reset();
+}
+
+void CrossPointWebServerActivity::loop() {
+  // Handle different states
+  switch (state) {
+    case WebServerActivityState::WIFI_SELECTION:
+      // Forward loop to WiFi selection subactivity
+      if (wifiSelection) {
+        wifiSelection->loop();
+      }
+      break;
+
+    case WebServerActivityState::SERVER_RUNNING:
+      // Handle web server requests - call handleClient multiple times per loop
+      // to improve responsiveness and upload throughput
+      if (webServer && webServer->isRunning()) {
+        unsigned long timeSinceLastHandleClient = millis() - lastHandleClientTime;
+
+        // Log if there's a significant gap between handleClient calls (>100ms)
+        if (lastHandleClientTime > 0 && timeSinceLastHandleClient > 100) {
+          Serial.printf("[%lu] [WEBACT] WARNING: %lu ms gap since last handleClient\n", millis(),
+                        timeSinceLastHandleClient);
+        }
+
+        // Call handleClient multiple times to process pending requests faster
+        // This is critical for upload performance - HTTP file uploads send data
+        // in chunks and each handleClient() call processes incoming data
+        constexpr int HANDLE_CLIENT_ITERATIONS = 10;
+        for (int i = 0; i < HANDLE_CLIENT_ITERATIONS && webServer->isRunning(); i++) {
+          webServer->handleClient();
+        }
+        lastHandleClientTime = millis();
+      }
+
+      // Handle exit on Back button
+      if (inputManager.wasPressed(InputManager::BTN_BACK)) {
+        onGoBack();
+        return;
+      }
+      break;
+
+    case WebServerActivityState::SHUTTING_DOWN:
+      // Do nothing - waiting for cleanup
+      break;
+  }
+}
+
+void CrossPointWebServerActivity::displayTaskLoop() {
+  while (true) {
+    if (updateRequired) {
+      updateRequired = false;
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      render();
+      xSemaphoreGive(renderingMutex);
+    }
+    vTaskDelay(10 / portTICK_PERIOD_MS);
+  }
+}
+
+void CrossPointWebServerActivity::render() const {
+  // Only render our own UI when server is running
+  // WiFi selection handles its own rendering
+  if (state == WebServerActivityState::SERVER_RUNNING) {
+    renderer.clearScreen();
+    renderServerRunning();
+    renderer.displayBuffer();
+  }
+}
+
+void CrossPointWebServerActivity::renderServerRunning() const {
+  const auto pageWidth = GfxRenderer::getScreenWidth();
+  const auto pageHeight = GfxRenderer::getScreenHeight();
+  const auto height = renderer.getLineHeight(UI_FONT_ID);
+  const auto top = (pageHeight - height * 5) / 2;
+
+  renderer.drawCenteredText(READER_FONT_ID, top - 30, "File Transfer", true, BOLD);
+
+  std::string ssidInfo = "Network: " + connectedSSID;
+  if (ssidInfo.length() > 28) {
+    ssidInfo = ssidInfo.substr(0, 25) + "...";
+  }
+  renderer.drawCenteredText(UI_FONT_ID, top + 10, ssidInfo.c_str(), true, REGULAR);
+
+  std::string ipInfo = "IP Address: " + connectedIP;
+  renderer.drawCenteredText(UI_FONT_ID, top + 40, ipInfo.c_str(), true, REGULAR);
+
+  // Show web server URL prominently
+  std::string webInfo = "http://" + connectedIP + "/";
+  renderer.drawCenteredText(UI_FONT_ID, top + 70, webInfo.c_str(), true, BOLD);
+
+  renderer.drawCenteredText(SMALL_FONT_ID, top + 110, "Open this URL in your browser", true, REGULAR);
+
+  renderer.drawCenteredText(SMALL_FONT_ID, pageHeight - 30, "Press BACK to exit", true, REGULAR);
+}
@@ -0,0 +1,66 @@
+#pragma once
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <functional>
+#include <memory>
+#include <string>
+
+#include "../Activity.h"
+#include "WifiSelectionActivity.h"
+#include "server/CrossPointWebServer.h"
+
+// Web server activity states
+enum class WebServerActivityState {
+  WIFI_SELECTION,  // WiFi selection subactivity is active
+  SERVER_RUNNING,  // Web server is running and handling requests
+  SHUTTING_DOWN    // Shutting down server and WiFi
+};
+
+/**
+ * CrossPointWebServerActivity is the entry point for file transfer functionality.
+ * It:
+ * - Immediately turns on WiFi and launches WifiSelectionActivity on enter
+ * - When WifiSelectionActivity completes successfully, starts the CrossPointWebServer
+ * - Handles client requests in its loop() function
+ * - Cleans up the server and shuts down WiFi on exit
+ */
+class CrossPointWebServerActivity final : public Activity {
+  TaskHandle_t displayTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+  bool updateRequired = false;
+  WebServerActivityState state = WebServerActivityState::WIFI_SELECTION;
+  const std::function<void()> onGoBack;
+
+  // WiFi selection subactivity
+  std::unique_ptr<WifiSelectionActivity> wifiSelection;
+
+  // Web server - owned by this activity
+  std::unique_ptr<CrossPointWebServer> webServer;
+
+  // Server status
+  std::string connectedIP;
+  std::string connectedSSID;
+
+  // Performance monitoring
+  unsigned long lastHandleClientTime = 0;
+
+  static void taskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+  void render() const;
+  void renderServerRunning() const;
+
+  void onWifiSelectionComplete(bool connected);
+  void startWebServer();
+  void stopWebServer();
+
+ public:
+  explicit CrossPointWebServerActivity(GfxRenderer& renderer, InputManager& inputManager,
+                                       const std::function<void()>& onGoBack)
+      : Activity(renderer, inputManager), onGoBack(onGoBack) {}
+  void onEnter() override;
+  void onExit() override;
+  void loop() override;
+  bool skipLoopDelay() override { return webServer && webServer->isRunning(); }
+};
@@ -0,0 +1,108 @@
+#pragma once
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <cstdint>
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "../Activity.h"
+#include "../util/KeyboardEntryActivity.h"
+
+// Structure to hold WiFi network information
+struct WifiNetworkInfo {
+  std::string ssid;
+  int32_t rssi;
+  bool isEncrypted;
+  bool hasSavedPassword;  // Whether we have saved credentials for this network
+};
+
+// WiFi selection states
+enum class WifiSelectionState {
+  SCANNING,           // Scanning for networks
+  NETWORK_LIST,       // Displaying available networks
+  PASSWORD_ENTRY,     // Entering password for selected network
+  CONNECTING,         // Attempting to connect
+  CONNECTED,          // Successfully connected
+  SAVE_PROMPT,        // Asking user if they want to save the password
+  CONNECTION_FAILED,  // Connection failed
+  FORGET_PROMPT       // Asking user if they want to forget the network
+};
+
+/**
+ * WifiSelectionActivity is responsible for scanning WiFi APs and connecting to them.
+ * It will:
+ * - Enter scanning mode on entry
+ * - List available WiFi networks
+ * - Allow selection and launch KeyboardEntryActivity for password if needed
+ * - Save the password if requested
+ * - Call onComplete callback when connected or cancelled
+ *
+ * The onComplete callback receives true if connected successfully, false if cancelled.
+ */
+class WifiSelectionActivity final : public Activity {
+  TaskHandle_t displayTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+  bool updateRequired = false;
+  WifiSelectionState state = WifiSelectionState::SCANNING;
+  int selectedNetworkIndex = 0;
+  std::vector<WifiNetworkInfo> networks;
+  const std::function<void(bool connected)> onComplete;
+
+  // Selected network for connection
+  std::string selectedSSID;
+  bool selectedRequiresPassword = false;
+
+  // On-screen keyboard for password entry
+  std::unique_ptr<KeyboardEntryActivity> keyboard;
+
+  // Connection result
+  std::string connectedIP;
+  std::string connectionError;
+
+  // Password to potentially save (from keyboard or saved credentials)
+  std::string enteredPassword;
+
+  // Whether network was connected using a saved password (skip save prompt)
+  bool usedSavedPassword = false;
+
+  // Save/forget prompt selection (0 = Yes, 1 = No)
+  int savePromptSelection = 0;
+  int forgetPromptSelection = 0;
+
+  // Connection timeout
+  static constexpr unsigned long CONNECTION_TIMEOUT_MS = 15000;
+  unsigned long connectionStartTime = 0;
+
+  static void taskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+  void render() const;
+  void renderNetworkList() const;
+  void renderPasswordEntry() const;
+  void renderConnecting() const;
+  void renderConnected() const;
+  void renderSavePrompt() const;
+  void renderConnectionFailed() const;
+  void renderForgetPrompt() const;
+
+  void startWifiScan();
+  void processWifiScanResults();
+  void selectNetwork(int index);
+  void attemptConnection();
+  void checkConnectionStatus();
+  std::string getSignalStrengthIndicator(int32_t rssi) const;
+
+ public:
+  explicit WifiSelectionActivity(GfxRenderer& renderer, InputManager& inputManager,
+                                 const std::function<void(bool connected)>& onComplete)
+      : Activity(renderer, inputManager), onComplete(onComplete) {}
+  void onEnter() override;
+  void onExit() override;
+  void loop() override;
+
+  // Get the IP address after successful connection
+  const std::string& getConnectedIP() const { return connectedIP; }
+};
--- a/Show More
+++ b/Show More