Project Challenge
Objective
Developing a file transfer solution that works without relying on internet connectivity or Bluetooth pairing was our primary challenge. Traditional file sharing apps required network connectivity, complicated setup processes, or created security vulnerabilities. We aimed to create an elegant solution that would allow instant device-to-device file transfers using just the device cameras and QR code technology, making sharing as simple as pointing and scanning.
Approach
Technical Architecture
We designed a streamlined system where QR codes serve as the configuration mechanism rather than the transfer medium. The sender device generates a QR code containing local network information, port details, and connection parameters. When scanned, this allows the receiver to automatically configure network settings and establish a direct device-to-device connection over local ports without requiring manual setup or internet connectivity. This approach eliminates the complexity of traditional file sharing while maintaining transfer speeds comparable to direct USB connections.
The Receiver
Implementation
Send It creates a secure server on the sender device, using available local ports and configuring firewall exceptions automatically. The connection details are encoded into a compact QR code which, when scanned by the receiver, establishes a direct socket connection between devices. Files transfer at native network speeds (up to 40MB/s on local WiFi), with built-in integrity checks ensuring accurate delivery. The system works across different Android versions and even on devices with varying hardware capabilities, making file sharing universally accessible without the technical hurdles of traditional methods.