FlexHub ·

Offline file transfer guide

Send from a phone over Transfer Hub Wi-Fi and receive on a computer over USB. No internet is needed after downloading the offline package.

Prepare the offline package

  1. Download FlexHub-Offline.zip and extract all files. Do not open the HTML inside a ZIP preview. Keep the extracted folder.
  2. Connect Transfer Hub to the receiving computer using a USB data cable. Close other apps or tabs using its serial port.

Receive on the computer

  1. Open FlexHub-Receiver.html in Chrome / Edge. Enter the device login password, click “连接 USB 并登录” (connect USB and log in), then select Transfer Hub in the permission dialog. COM numbers vary.
  2. Click “选择接收文件夹” (choose receiving folder), allow writing, and wait until ready. Passwords are not bundled; the device login password may differ from the Wi-Fi password.

Send from the phone

  1. On the phone, join transferhub using the device Wi-Fi password. Stay connected despite the no-internet notice.
  2. Choose “发送文件” (send) in the captive portal. If it does not appear or cannot select a file, open http://192.168.77.1/ in a normal browser.
  3. Log in with the device password, select a file, and send once the computer is ready. Wait for confirmation that the computer saved and verified the file, then check the folder.

Troubleshooting and limits

  1. Keep both pages open and devices awake. The computer need not join Transfer Hub Wi-Fi; files reach it over USB.
  2. Waiting for receiver: check USB login and folder permission. After unplugging or flashing, reconnect and choose the folder again.
  3. Missing port: check the data cable, dedicated firmware, and other apps or tabs that may own the port.
  4. The Transfer Hub HTTP page and captive mini-browser cannot directly access USB. Use the downloaded HTML or a trusted HTTPS receiver page.
  5. One file at a time; configured maximum 4 GiB, not yet hardware-tested at that size. Disk space and filesystem limits also apply. Start with a small file.
  6. Updated firmware + receiver page: phone uploads retry automatically; after Wi-Fi returns, select the same file and click 继续传输 (resume). Keep the USB receiver page open and connected; paused state expires after 10 minutes. For computer-to-phone downloads, use Resume in the browser download list if supported; keep the USB source page open. Click Cancel after finishing to release the channel. Reboot, USB unplugging, receiver-page closure, or expiry requires restarting. Duplicate filenames are renamed.
  7. Files are not uploaded to the website. The downloaded receiver works without internet. The transfer controls currently use Chinese; this guide includes the matching button labels.
  8. With bidirectional firmware, send from the USB computer: log in, choose 发送 (send), and select a file. On the phone hotspot page, log in, choose 接收 (receive), then download. No computer destination folder is needed for sending. Only one direction runs at a time. Completion means data was submitted to the download connection; confirm saving in the phone browser download list. Older firmware supports phone-to-computer only.

Open receiver