Calibre Web Epub Downloading + Calibre Wireless Device Syncing by itsthisjustin · Pull Request #219 · crosspoint-reader/crosspoint-reader

itsthisjustin · 2026-01-03T01:07:06Z

Summary

Adds support for browsing and downloading books from a Calibre-web server via OPDS.

How it works

Configure server URL in Settings → Calibre Web URL (e.g., https://myserver.com:port I use Cloudflare tunnel to make my server accessible anywhere fwiw)
"Calibre Library" will now show on the the home screen
Browse the catalog - navigate through categories like "By Newest", "By Author", "By Series", etc.
Download books - select a book and press Confirm to download the EPUB to your device

Navigation

Up/Down - Move through entries
Confirm - Open folder or download book
Back - Go to parent catalog, or exit to home if at root
Navigation entries show with > prefix, books show title and author
Button hints update dynamically ("Open" for folders, "Download" for books)

Technical details

Fetches OPDS catalog from {server_url}/opds
Parses both navigation feeds (catalog links) and acquisition feeds (downloadable books)
Maintains navigation history stack for back navigation
Handles absolute paths in OPDS links correctly (e.g., /books/opds/navcatalog/...)
Downloads EPUBs directly to the SD card root

Note

The server URL should be typed to include https:// if the server requires it - HTTP→HTTPS redirects may cause SSL errors on ESP32.

Additional Context

I also changed the home titles to use uppercase for each word and added a setting to change the size of the side margins

Also made the menu items dynamic and capital case. Looks better from a design perspective but I suppose this is an optional thing to accept

itsthisjustin · 2026-01-03T05:46:52Z

Oh and this can be tested if anyone wants to by putting https://home.jmitch.com/books as the calibre web url

daveallie · 2026-01-03T08:21:46Z

OPDS is a huge add, thanks for this @itsthisjustin, given the size of the PR, I'll need to take a little bit to review this, but excited for it!

itsthisjustin · 2026-01-03T08:57:53Z

Totally understand. Also added Calibre Wireless Device syncing to this as well so you can auto discover Calibre servers and send to device from there. Working on koreader sync in another branch now

daveallie · 2026-01-04T02:40:43Z

src/CrossPointSettings.cpp

+int CrossPointSettings::getReaderSideMargin() const {
+  switch (sideMargin) {
+    case MARGIN_NONE:
+      return 0;
+    case MARGIN_SMALL:
+    default:
+      return 5;
+    case MARGIN_MEDIUM:
+      return 20;
+    case MARGIN_LARGE:
+      return 30;
+  }
+}


Would love to keep this split out to avoid merge conflicts with other work, and to not over inflate large PRs

src/CrossPointSettings.cpp

daveallie · 2026-01-04T02:51:16Z

src/activities/browser/OpdsBookBrowserActivity.cpp

+// Prepend http:// if no protocol specified (server will redirect to https if needed)
+std::string ensureProtocol(const std::string& url) {
+  if (url.find("://") == std::string::npos) {
+    return "http://" + url;
+  }
+  return url;
+}
+
+// Extract host with protocol from URL (e.g., "http://example.com" from "http://example.com/path")
+std::string extractHost(const std::string& url) {
+  const size_t protocolEnd = url.find("://");
+  if (protocolEnd == std::string::npos) {
+    // No protocol, find first slash
+    const size_t firstSlash = url.find('/');
+    return firstSlash == std::string::npos ? url : url.substr(0, firstSlash);
+  }
+  // Find the first slash after the protocol
+  const size_t hostStart = protocolEnd + 3;
+  const size_t pathStart = url.find('/', hostStart);
+  return pathStart == std::string::npos ? url : url.substr(0, pathStart);
+}
+
+// Build full URL from server URL and path
+// If path starts with /, it's an absolute path from the host root
+// Otherwise, it's relative to the server URL
+std::string buildUrl(const std::string& serverUrl, const std::string& path) {
+  const std::string urlWithProtocol = ensureProtocol(serverUrl);
+  if (path.empty()) {
+    return urlWithProtocol;
+  }
+  if (path[0] == '/') {
+    // Absolute path - use just the host
+    return extractHost(urlWithProtocol) + path;
+  }
+  // Relative path - append to server URL
+  if (urlWithProtocol.back() == '/') {
+    return urlWithProtocol + path;
+  }
+  return urlWithProtocol + "/" + path;
+}


These have utility outside of this activity, and avoid bloating this activity lets move them into their own UrlUtils (or something similarly named) class

daveallie · 2026-01-04T02:56:08Z

src/activities/browser/OpdsBookBrowserActivity.cpp

+  std::string downloadUrl = buildUrl(SETTINGS.opdsServerUrl, book.href);
+
+  // Create sanitized filename
+  std::string filename = "/" + sanitizeFilename(book.title) + ".epub";


Could we please make the downloaded file name be <title> - <author>.epub

src/activities/home/HomeActivity.cpp

daveallie · 2026-01-04T03:06:34Z

src/activities/home/HomeActivity.cpp

+  std::vector<const char*> menuItems;
+  menuItems.push_back("Browse Files");
+  if (hasBrowserUrl) {
+    menuItems.push_back("Calibre Library");
+  }
+  menuItems.push_back("File Transfer");
+  menuItems.push_back("Settings");


nit: slightly cleaner way here might be instantiate the vector with the fixed three options and insert the fourth

std::vector<const char*> menuItems = { "Browse Files", "File Transfer", "Settings" }; if (hasBrowserUrl) { // Insert calibre library to be after browse files menuItems.insert(menuItems.begin() + 1, "Calibre Library"); }

daveallie · 2026-01-04T03:12:30Z

src/activities/home/HomeActivity.cpp

+    int idx = 0;
+    const int continueIdx = hasContinueReading ? idx++ : -1;
+    const int browseFilesIdx = idx++;
+    const int browseBookIdx = hasBrowserUrl ? idx++ : -1;


nit: can you please update these variables to be more reflective of their relationship to the OPDS browser, they are a bit confusing at the moment: hasOdpsUrl, browseOdpsFilesIdx, onOdpsBrowserOpen

daveallie · 2026-01-04T03:14:11Z

src/main.cpp

+  if (strlen(SETTINGS.opdsServerUrl) == 0) {
+    enterNewActivity(new KeyboardEntryActivity(
+        renderer, mappedInputManager, "Calibre Web URL", "", 10, 127, false,
+        [](const std::string& url) {
+          strncpy(SETTINGS.opdsServerUrl, url.c_str(), sizeof(SETTINGS.opdsServerUrl) - 1);
+          SETTINGS.opdsServerUrl[sizeof(SETTINGS.opdsServerUrl) - 1] = '\0';
+          SETTINGS.saveToFile();
+          exitActivity();
+          enterNewActivity(new OpdsBookBrowserActivity(renderer, mappedInputManager, onGoHome));
+        },
+        [] {
+          exitActivity();
+          onGoHome();
+        }));
+  } else {


I don't think it's possible for this branch to ever be hit as HomeActivity validates that the value is set before calling this. It would simplify this file to remove it. Additionally, OpdsBookBrowserActivity already gracefully handles a missing SETTINGS.opdsServerUrl, so there's no risk of a crash or anything.

src/activities/network/CalibreWirelessActivity.cpp

daveallie · 2026-01-04T03:20:39Z

src/main.cpp

+  // Check WiFi connectivity first
+  if (WiFi.status() != WL_CONNECTED) {
+    enterNewActivity(new WifiSelectionActivity(renderer, mappedInputManager, [](bool connected) {
+      exitActivity();
+      if (connected) {
+        launchBrowserWithUrlCheck();
+      } else {
+        onGoHome();
+      }
+    }));
+  } else {
+    launchBrowserWithUrlCheck();
+  }


Is it even possible for the wifi to be connected before this function is called?

Additionally, WifiSelectionActivity is not responsible for turning on and off the Wifi chip, even though it does a mode set when starting the scan (which by proxy turns on the wifi). Critically, the changes here never turn off the wifi when existing the OPDS brower, resulting in the Wifi being left on.

I would love all this existing logic (if necessary) and the Wifi control logic to be wrapped up into the activity (or an activity which launches the OpdsBookBrowserActivity). main.cpp should not need to know that OpdsBookBrowserActivity requires an active Wifi connection or that SETTINGS.opdsServerUrl is set, that should be a responsibility of the activity.

Is it even possible for the wifi to be connected before this function is called?

Soooo not now? But I was thinking in the future it might. (especially now that I have KOReader Sync working, it might be a thing that the user sets the device to connect to wifi at some interval to sync on their behalf)

It just becomes a bit messy understanding the responsibility for enabling/disabling Wifi.

Given the battery drain of using wifi, I would love for the functions using it to be wrapped within blocks enabling and disabling it.

… how the KOReader PR works too

daveallie · 2026-01-04T03:29:11Z

src/activities/network/CalibreWirelessActivity.h

+  static constexpr uint16_t UDP_PORTS[] = {54982, 48123, 39001, 44044, 59678};
+  static constexpr size_t UDP_PORT_COUNT = 5;
+  static constexpr uint16_t LOCAL_UDP_PORT = 8134;  // Port to receive responses


If these are only needed as static private variables, please move them into an anonymous namespace in the CPP file. Additionally, if UDP_PORTS is statically assigned, you should just be able to use std::size(UDP_PORTS) in place of UDP_PORT_COUNT

daveallie · 2026-01-04T03:31:53Z

src/activities/network/CalibreWirelessActivity.h

+  // Calibre protocol opcodes (from calibre/devices/smart_device_app/driver.py)
+  static constexpr int OP_OK = 0;
+  static constexpr int OP_SET_CALIBRE_DEVICE_INFO = 1;
+  static constexpr int OP_SET_CALIBRE_DEVICE_NAME = 2;
+  static constexpr int OP_GET_DEVICE_INFORMATION = 3;
+  static constexpr int OP_TOTAL_SPACE = 4;
+  static constexpr int OP_FREE_SPACE = 5;
+  static constexpr int OP_GET_BOOK_COUNT = 6;
+  static constexpr int OP_SEND_BOOKLISTS = 7;
+  static constexpr int OP_SEND_BOOK = 8;
+  static constexpr int OP_GET_INITIALIZATION_INFO = 9;
+  static constexpr int OP_BOOK_DONE = 11;
+  static constexpr int OP_NOOP = 12;  // Was incorrectly 18
+  static constexpr int OP_DELETE_BOOK = 13;
+  static constexpr int OP_GET_BOOK_FILE_SEGMENT = 14;
+  static constexpr int OP_GET_BOOK_METADATA = 15;
+  static constexpr int OP_SEND_BOOK_METADATA = 16;
+  static constexpr int OP_DISPLAY_MESSAGE = 17;
+  static constexpr int OP_CALIBRE_BUSY = 18;
+  static constexpr int OP_SET_LIBRARY_INFO = 19;
+  static constexpr int OP_ERROR = 20;


Would it make more sense to declare these as an enum mapping to uint8_t values?

src/activities/network/CalibreWirelessActivity.h

daveallie · 2026-01-04T03:36:02Z

src/activities/settings/SettingsActivity.cpp

     {"Justify", "Left", "Center", "Right"}},
+    {"Reader Side Margin", SettingType::ENUM, &CrossPointSettings::sideMargin, {"None", "Small", "Medium", "Large"}},
+    {"Calibre Web URL", SettingType::ACTION, nullptr, {}},
+    {"Calibre Wireless Device", SettingType::TOGGLE, &CrossPointSettings::calibreWirelessEnabled, {}},


Why does this need to be a TOGGLE and not an ACTION? Afaict you're always just disabling/enabling the setting when it's selected and the sub activity is entered / left. Is there any real need for globalisation or persistence of this value?

src/activities/network/CalibreWirelessActivity.cpp

daveallie · 2026-01-04T03:55:24Z

src/activities/network/CalibreWirelessActivity.cpp

+  // Report 10GB free space
+  sendJsonResponse(OP_OK, "{\"free_space_on_device\":10737418240}");


Can you add a future TODO here so we can update it with the actual card free space in the future?

src/activities/network/CalibreWirelessActivity.cpp

daveallie · 2026-01-04T04:03:10Z

src/activities/network/CalibreWirelessActivity.cpp

+
+  // Draw progress if receiving
+  if (state == CalibreWirelessState::RECEIVING && currentFileSize > 0) {
+    const int percent = static_cast<int>((bytesReceived * 100) / currentFileSize);


This will overflow for books over ~20.5MB. Probably the safest way around this is:

static_cast<int>(static_cast<float>(bytesReceived) / static_cast<float>(currentFileSize) * 100f);

Any idea what the average size of an epub that people are putting on this device? Curious as I was also trying to figure out a safe number for the free space

10GB is totally fine, just doesn't protect against a full SD card in the future. Most of my EPUBs are only a few MB, but there are some chonkers, like Wind and Truth is 23.4MB, which would overflow here.

daveallie · 2026-01-04T04:05:09Z

src/activities/network/CalibreWirelessActivity.cpp

+    // Progress bar
+    const int barWidth = pageWidth - 100;
+    const int barHeight = 20;
+    const int barX = 50;
+    const int barY = statusY + 20;
+
+    renderer.drawRect(barX, barY, barWidth, barHeight);
+    renderer.fillRect(barX + 2, barY + 2, (barWidth - 4) * percent / 100, barHeight - 4);
+
+    // Percentage text
+    const std::string percentText = std::to_string(percent) + "%";
+    renderer.drawCenteredText(UI_10_FONT_ID, barY + barHeight + 15, percentText.c_str());


I noticed that you've done a progress bar here but, not for the OPDS downloader. GIven its reuse here, in the OTA downloader, and in the OPDS downloader, let's extract it out to a new function in ScreenComponents and allow it to take x, y, width, height, percent

Yep good call out. I did this after the fact and it SHOULD go here as well

daveallie · 2026-01-04T04:05:49Z

src/activities/network/CalibreWirelessActivity.cpp

+std::string CalibreWirelessActivity::sanitizeFilename(const std::string& name) const {
+  std::string result;
+  result.reserve(name.size());
+
+  for (char c : name) {
+    if (c == '/' || c == '\\' || c == ':' || c == '*' || c == '?' || c == '"' || c == '<' || c == '>' || c == '|') {
+      result += '_';
+    } else if (c >= 32 && c < 127) {
+      result += c;
+    }
+  }
+
+  // Trim leading/trailing spaces and dots
+  size_t start = 0;
+  while (start < result.size() && (result[start] == ' ' || result[start] == '.')) {
+    start++;
+  }
+  size_t end = result.size();
+  while (end > start && (result[end - 1] == ' ' || result[end - 1] == '.')) {
+    end--;
+  }
+
+  return result.substr(start, end - start);
+}


GIven the reuse, it would be good to split this out into some common string utils

itsthisjustin · 2026-01-04T04:44:46Z

Side note @daveallie I found that switching between my two branches soft bricked my device as it had settings from one flash that didn't exist in the next so I'm curious if we should add a failsafe to reset the settings file if this happens so that at least the device boots

…eb-and-margins # Conflicts: # src/CrossPointSettings.cpp # src/CrossPointSettings.h # src/activities/settings/SettingsActivity.cpp

daveallie · 2026-01-04T05:08:13Z

I'll resist looking back through every commit/comment in the PR, please rerequest my review via GH's review system or by comment once it's good for another look

itsthisjustin · 2026-01-04T05:09:05Z

Item	Status
Split out margin settings	✅ Removed
UrlUtils class	✅ src/util/UrlUtils.h
Download filename <title> - .epub	✅ Done
Menu vector insert()	✅ Done
Opds variable naming	✅ hasOpdsUrl, onOpdsBrowserOpen
Remove dead branch in main.cpp	✅ Simplified
Activity handles WiFi	✅ CHECK_WIFI state
UDP_PORTS anonymous namespace	✅ With range-based for loop
Spec source documentation	✅ URL in header comment
TOGGLE → ACTION for Calibre	✅ CalibreSettingsActivity
stateMutex before task delete	✅ Line 77-78
String insert for packet	✅ Line 390
Stub opcodes comments	✅ Lines 424-434
ccVersionNumber 212 comment	✅ Line 466
coverHeight 800	✅ Line 469-470
CROSSPOINT_VERSION	✅ Lines 488, 491
TODO for free space	✅ Line 498
Unknown opcode logging	✅ Line 441
Overflow fix (64-bit)	✅ ScreenComponents.cpp line 51
Progress bar in ScreenComponents	✅ drawProgressBar()
StringUtils	✅ src/util/StringUtils.h

itsthisjustin · 2026-01-04T05:11:33Z

Only thing I want to make sure you saw was that while you were reviewing I changed the Calibre settings into a submenu system to avoid an ever growing settings list. I'd recommend eventually we do this to other settings like "Reader Preferences", "Device Sleep Settings" or whatever we can group into submenus 2976113

daveallie · 2026-01-04T05:13:16Z

Yeah definitely on board with this change, was mentioning it elsewhere, happy for this to be the first group to move.

daveallie

Few more bits, plus some comments in CalibreWirelessActivity which need addressing/replies

daveallie · 2026-01-04T05:18:09Z

src/main.cpp

+#include "activities/browser/OpdsBookBrowserActivity.h"
 #include "activities/home/HomeActivity.h"
 #include "activities/network/CrossPointWebServerActivity.h"
+#include "activities/network/WifiSelectionActivity.h"


nit: this can be removed

Need Opds because it's what allows the onGoToBrowser() to work

onGoToBrowser just calls enterNewActivity(new OpdsBookBrowserActivity(renderer, mappedInputManager, onGoHome)); which has no dependency on WifiSelectionActivity?

I'll double check but the opds browser doesnt technically launch until the wifi selection activity shows. It's a prereq for showing the browser that they must connect to a wifi network first.

daveallie · 2026-01-04T05:18:15Z

src/main.cpp

 #include "activities/reader/ReaderActivity.h"
 #include "activities/settings/SettingsActivity.h"
 #include "activities/util/FullScreenMessageActivity.h"
+#include "activities/util/KeyboardEntryActivity.h"


nit: this can be removed

daveallie · 2026-01-04T05:18:26Z

src/main.cpp

 #include <InputManager.h>
 #include <SDCardManager.h>
 #include <SPI.h>
+#include <WiFi.h>


nit: this can be removed

src/activities/settings/CalibreSettingsActivity.cpp

DJPoulter · 2026-01-04T14:47:13Z

Any chance you can add the option for username and password for opds. To allow access to Calibre-web Automated.

itsthisjustin · 2026-01-04T17:31:43Z

Any chance you can add the option for username and password for opds. To allow access to Calibre-web Automated.

Totally, but I'd say let's get this merged first so it's a smaller PR later to add that. I can add it this week

daveallie · 2026-01-05T08:28:52Z

Any chance you can add the option for username and password for opds. To allow access to Calibre-web Automated.

If it's setup anything like my personal setup, you can use HTTP basic auth in the URL to do username and password, so instead of http://host.to.your.opds.server.com, you use http://yourusername:[email protected]

daveallie · 2026-01-05T08:34:54Z

Would love your thoughts on these ones before merging:

Also looks like there's a small formatting issue which can be fixed by running the format script, but other than that, this looks good!

Resolves conflicts in CrossPointSettings.cpp and SettingsActivity.cpp: - Combines opdsServerUrl (feature branch) with screenMargin and sleepScreenCoverMode (master) in settings persistence - Updates settings count to 16 persisted fields - Merges settings UI to include all new settings plus Calibre Settings action - Adopts new SettingInfo factory pattern from master

itsthisjustin · 2026-01-05T16:52:36Z

Would love your thoughts on these ones before merging:

#219 (changes)

#219 (changes)

#219 (changes)

#219 (changes)

#219 (changes)

Also looks like there's a small formatting issue which can be fixed by running the format script, but other than that, this looks good!

I think all of these are done no?

I wasn't 100% sure this wasn't left over from me but gitblame says it came from someone else. Either way I don't see anywhere it's used so I THINK it's dead code

StuckInAWell · 2026-01-13T04:14:51Z

Hey there guys. Thrilled by this development, now I'm just hoping i can figure out why it's not working for me.

I haven't used Calibre much, but it seems like I set it up right...

I've set up Calibre on my homeserver, and set up the webserver and wireless connection settings.

I also added it to my DDNS to have it accessible from outside. This much has been tested and I can see my library from a browser at that url.

From the x4, I set the URL and I can connect as a wireless device. It sees the server by name, and says it's waiting for commands.

This is where it starts to act up. Even though it says waiting for commands, I have only once seen Calibre on my server show the "devices" menu at the top. Nothing was done differently, but I went to change the setting mentioned in the post, and then it hung on the x4.

Additionally, when trying to browse the Calibre Library from the home screen on the x4, it opens (sometimes with a glitchy double screen), then has me select the wifi, connects, and then errors out.

This is the point where I'm lost. Other devices can see the library in a browser, but the X4 cant load it. I've verified the URL, and still no dice.

Happy to try anything you suggest.

itsthisjustin · 2026-01-13T04:36:24Z

Hey there guys. Thrilled by this development, now I'm just hoping i can figure out why it's not working for me.

I haven't used Calibre much, but it seems like I set it up right...

I've set up Calibre on my homeserver, and set up the webserver and wireless connection settings.

I also added it to my DDNS to have it accessible from outside. This much has been tested and I can see my library from a browser at that url.

From the x4, I set the URL and I can connect as a wireless device. It sees the server by name, and says it's waiting for commands.

This is where it starts to act up. Even though it says waiting for commands, I have only once seen Calibre on my server show the "devices" menu at the top. Nothing was done differently, but I went to change the setting mentioned in the post, and then it hung on the x4.

Additionally, when trying to browse the Calibre Library from the home screen on the x4, it opens (sometimes with a glitchy double screen), then has me select the wifi, connects, and then errors out.

This is the point where I'm lost. Other devices can see the library in a browser, but the X4 cant load it. I've verified the URL, and still no dice.

Happy to try anything you suggest.

So just to confirm, you are trying to use both the calibre library AND wireless device syncing right? they are two completely different features so I just want to make sure you're not mixing them. For calibre wireless device I just right click the book I want to send and I send to device A or whatever it says. That works. If you are using DDNS with the wireless device thing I'm not 100% sure that will work because it requires UDP commands to work and that might be blocked. You'd want to use this on your local network. I hate to be that guy, but you may want to just make 100% sure you can use the wireless device syncing with another device other than the x4 first just to make sure that's set up correctly and its not some weird internal internet/port issue.

As far as the library issue, I'd probably say the same thing. I tried this with DDNS myself and I could never get it working correctly so I ended up using cloudflare tunnels. Wasn't an issue with the x4 as much as some stupid network thing with ssl and port forwarding so gave up and switched up how I was exposing it.

StuckInAWell · 2026-01-13T04:51:24Z

Hey there guys. Thrilled by this development, now I'm just hoping i can figure out why it's not working for me.
I haven't used Calibre much, but it seems like I set it up right...
I've set up Calibre on my homeserver, and set up the webserver and wireless connection settings.
I also added it to my DDNS to have it accessible from outside. This much has been tested and I can see my library from a browser at that url.
From the x4, I set the URL and I can connect as a wireless device. It sees the server by name, and says it's waiting for commands.
This is where it starts to act up. Even though it says waiting for commands, I have only once seen Calibre on my server show the "devices" menu at the top. Nothing was done differently, but I went to change the setting mentioned in the post, and then it hung on the x4.
Additionally, when trying to browse the Calibre Library from the home screen on the x4, it opens (sometimes with a glitchy double screen), then has me select the wifi, connects, and then errors out.
This is the point where I'm lost. Other devices can see the library in a browser, but the X4 cant load it. I've verified the URL, and still no dice.
Happy to try anything you suggest.

So just to confirm, you are trying to use both the calibre library AND wireless device syncing right? they are two completely different features so I just want to make sure you're not mixing them. For calibre wireless device I just right click the book I want to send and I send to device A or whatever it says. That works. If you are using DDNS with the wireless device thing I'm not 100% sure that will work because it requires UDP commands to work and that might be blocked. You'd want to use this on your local network. I hate to be that guy, but you may want to just make 100% sure you can use the wireless device syncing with another device other than the x4 first just to make sure that's set up correctly and its not some weird internal internet/port issue.

As far as the library issue, I'd probably say the same thing. I tried this with DDNS myself and I could never get it working correctly so I ended up using cloudflare tunnels. Wasn't an issue with the x4 as much as some stupid network thing with ssl and port forwarding so gave up and switched up how I was exposing it.

Nah, just trying to use one or the other. Wireless device goes over local network, not the DDNS. I did JUST test it with a jailbroken kindle with KOReader and I was able to send a file from Calibre to it.

I can send you the DDNS url privately if you are interested in testing it on your end. I use the same system to expose Jellyfin without a problem.

itsthisjustin · 2026-01-13T04:59:23Z

Hey there guys. Thrilled by this development, now I'm just hoping i can figure out why it's not working for me.
I haven't used Calibre much, but it seems like I set it up right...
I've set up Calibre on my homeserver, and set up the webserver and wireless connection settings.
I also added it to my DDNS to have it accessible from outside. This much has been tested and I can see my library from a browser at that url.
From the x4, I set the URL and I can connect as a wireless device. It sees the server by name, and says it's waiting for commands.
This is where it starts to act up. Even though it says waiting for commands, I have only once seen Calibre on my server show the "devices" menu at the top. Nothing was done differently, but I went to change the setting mentioned in the post, and then it hung on the x4.
Additionally, when trying to browse the Calibre Library from the home screen on the x4, it opens (sometimes with a glitchy double screen), then has me select the wifi, connects, and then errors out.
This is the point where I'm lost. Other devices can see the library in a browser, but the X4 cant load it. I've verified the URL, and still no dice.
Happy to try anything you suggest.

So just to confirm, you are trying to use both the calibre library AND wireless device syncing right? they are two completely different features so I just want to make sure you're not mixing them. For calibre wireless device I just right click the book I want to send and I send to device A or whatever it says. That works. If you are using DDNS with the wireless device thing I'm not 100% sure that will work because it requires UDP commands to work and that might be blocked. You'd want to use this on your local network. I hate to be that guy, but you may want to just make 100% sure you can use the wireless device syncing with another device other than the x4 first just to make sure that's set up correctly and its not some weird internal internet/port issue.

As far as the library issue, I'd probably say the same thing. I tried this with DDNS myself and I could never get it working correctly so I ended up using cloudflare tunnels. Wasn't an issue with the x4 as much as some stupid network thing with ssl and port forwarding so gave up and switched up how I was exposing it.

Nah, just trying to use one or the other. Wireless device goes over local network, not the DDNS. I did JUST test it with a jailbroken kindle with KOReader and I was able to send a file from Calibre to it.

I can send you the DDNS url privately if you are interested in testing it on your end. I use the same system to expose Jellyfin without a problem.

Of course. Email me. [email protected]

itsthisjustin · 2026-01-13T07:39:03Z

Hey there guys. Thrilled by this development, now I'm just hoping i can figure out why it's not working for me.

I haven't used Calibre much, but it seems like I set it up right...

I've set up Calibre on my homeserver, and set up the webserver and wireless connection settings.

I also added it to my DDNS to have it accessible from outside. This much has been tested and I can see my library from a browser at that url.

The original feature assumed SSL and failed if you didn't have a cert. PR incoming

alnav3 · 2026-01-14T18:42:31Z

Hey guys! Sorry to bother

I was thinking of buying this ereader and install crosspoint, however one of the non-negotiables im looking at is progress syncing through calibre-web with both the xteink x4 and my kobo libra (it's already working through kobo devices just fine)

As long as i understand, this PR has just added this feature to the device, so in theory if i install crosspoint i can configure the calibre endpoint just as i did with my kobo and sync all books progress through both of them, right?

itsthisjustin · 2026-01-14T19:44:50Z

Hey guys! Sorry to bother

I was thinking of buying this ereader and install crosspoint, however one of the non-negotiables im looking at is progress syncing through calibre-web with both the xteink x4 and my kobo libra (it's already working through kobo devices just fine)

As long as i understand, this PR has just added this feature to the device, so in theory if i install crosspoint i can configure the calibre endpoint just as i did with my kobo and sync all books progress through both of them, right?

This isn't for syncing progress. Do you run KOReader on your kobo?

itsthisjustin · 2026-01-14T20:29:49Z

@daveallie did anything change in main between this working and my merge related to networking? This 100% worked in testing and now is missing kb when a book finishes transfer. I've fixed the disconnect issue but transferring still isn't working and I can't figure out why

…point-reader#219) Adds support for browsing and downloading books from a Calibre-web server via OPDS. How it works 1. Configure server URL in Settings → Calibre Web URL (e.g., https://myserver.com:port I use Cloudflare tunnel to make my server accessible anywhere fwiw) 2. "Calibre Library" will now show on the the home screen 3. Browse the catalog - navigate through categories like "By Newest", "By Author", "By Series", etc. 4. Download books - select a book and press Confirm to download the EPUB to your device Navigation - Up/Down - Move through entries - Confirm - Open folder or download book - Back - Go to parent catalog, or exit to home if at root - Navigation entries show with > prefix, books show title and author - Button hints update dynamically ("Open" for folders, "Download" for books) Technical details - Fetches OPDS catalog from {server_url}/opds - Parses both navigation feeds (catalog links) and acquisition feeds (downloadable books) - Maintains navigation history stack for back navigation - Handles absolute paths in OPDS links correctly (e.g., /books/opds/navcatalog/...) - Downloads EPUBs directly to the SD card root Note The server URL should be typed to include https:// if the server requires it - HTTP→HTTPS redirects may cause SSL errors on ESP32. * I also changed the home titles to use uppercase for each word and added a setting to change the size of the side margins --------- Co-authored-by: Dave Allie <[email protected]>

…point-reader#219) ## Summary Adds support for browsing and downloading books from a Calibre-web server via OPDS. How it works 1. Configure server URL in Settings → Calibre Web URL (e.g., https://myserver.com:port I use Cloudflare tunnel to make my server accessible anywhere fwiw) 2. "Calibre Library" will now show on the the home screen 3. Browse the catalog - navigate through categories like "By Newest", "By Author", "By Series", etc. 4. Download books - select a book and press Confirm to download the EPUB to your device Navigation - Up/Down - Move through entries - Confirm - Open folder or download book - Back - Go to parent catalog, or exit to home if at root - Navigation entries show with > prefix, books show title and author - Button hints update dynamically ("Open" for folders, "Download" for books) Technical details - Fetches OPDS catalog from {server_url}/opds - Parses both navigation feeds (catalog links) and acquisition feeds (downloadable books) - Maintains navigation history stack for back navigation - Handles absolute paths in OPDS links correctly (e.g., /books/opds/navcatalog/...) - Downloads EPUBs directly to the SD card root Note The server URL should be typed to include https:// if the server requires it - HTTP→HTTPS redirects may cause SSL errors on ESP32. ## Additional Context * I also changed the home titles to use uppercase for each word and added a setting to change the size of the side margins --------- Co-authored-by: Dave Allie <[email protected]>

itsthisjustin added 7 commits January 2, 2026 19:39

Adds margin setting and calibre web

55c3815

Also made the menu items dynamic and capital case. Looks better from a design perspective but I suppose this is an optional thing to accept

removes hard coded library id

f37df89

changes the title of the browser page

c99b934

lets you navigate and download books now

2313937

fix from CI check

1e0728a

more CI checks

796e735

Apply clang-format fixes

9abf48b

itsthisjustin added 4 commits January 3, 2026 01:42

almost working smart device connection to calibre

23e87f0

working!

471dcc0

remove logging

a175eb1

Apply clang-format fixes

e457c86

itsthisjustin changed the title ~~Access Calibre Web and download epubs direct to device~~ Calibre Web Epub Downloading + Calibre Wireless Device Syncing Jan 3, 2026

itsthisjustin mentioned this pull request Jan 4, 2026

add settings for reader screen margin #223

Merged

daveallie requested changes Jan 4, 2026

View reviewed changes

daveallie reviewed Jan 4, 2026

View reviewed changes

Moves Calibre settings into 1 single Calibre setting which will match…

2976113

… how the KOReader PR works too

daveallie requested changes Jan 4, 2026

View reviewed changes

daveallie mentioned this pull request Jan 4, 2026

Adds KOReader Sync support #232

Merged

itsthisjustin added 2 commits January 3, 2026 23:52

addresses comments from maintainer

8e1ba00

Merge remote-tracking branch 'upstream/master' into feature/calibre-w…

1a462f0

…eb-and-margins # Conflicts: # src/CrossPointSettings.cpp # src/CrossPointSettings.h # src/activities/settings/SettingsActivity.cpp

itsthisjustin requested a review from daveallie January 4, 2026 05:09

daveallie requested changes Jan 4, 2026

View reviewed changes

Turn wifi off when exiting browser and wireless activities

cb21668

itsthisjustin requested a review from daveallie January 4, 2026 05:46

daveallie mentioned this pull request Jan 5, 2026

My Library: Tab bar w/ Recent Books + File Browser #250

Merged

itsthisjustin and others added 2 commits January 5, 2026 11:56

formatting and removed getReaderScreenMargin as it was never used

bc04c71

I wasn't 100% sure this wasn't left over from me but gitblame says it came from someone else. Either way I don't see anywhere it's used so I THINK it's dead code

Small cleanup

bbf715a

daveallie approved these changes Jan 7, 2026

View reviewed changes

daveallie merged commit b792b79 into crosspoint-reader:master Jan 7, 2026
1 check passed

lukestein mentioned this pull request Jan 9, 2026

Feature request: Instapaper integration #277

Closed

		// Report 10GB free space
		sendJsonResponse(OP_OK, "{\"free_space_on_device\":10737418240}");

Uh oh!

Conversation

itsthisjustin commented Jan 3, 2026

Summary

Additional Context

Uh oh!

itsthisjustin commented Jan 3, 2026

Uh oh!

daveallie commented Jan 3, 2026

Uh oh!

itsthisjustin commented Jan 3, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

itsthisjustin commented Jan 4, 2026

Uh oh!

daveallie commented Jan 4, 2026

Uh oh!

itsthisjustin commented Jan 4, 2026

Uh oh!

itsthisjustin commented Jan 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

daveallie commented Jan 4, 2026

Uh oh!

daveallie left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

itsthisjustin commented Jan 4, 2026 •

edited

Loading