Audio Barcode

Send and receive small data packets over sound. The packets have a size of 50 bits and transmitting one packet takes ~1.7 seconds.

Based on the protocol described in "Chirp technology: an introduction". It's not compatible with the Chirp protocol. The parameters for error correction are not published in the article.

Usage

Add this to your Cargo.toml:

[dependencies]
audio-barcode = { git = "https://github.com/Unrud/audio-barcode" }

Then you can do something like:

use audio_barcode::Transceiver;

// Init
const SAMPLE_RATE: u32 = 44100;
let mut transceiver = Transceiver::new(SAMPLE_RATE);

// Receive
loop {
    let sample: f32 = ...;
    if let Some(payload) = transceiver.push_sample(sample) {
        println!("Received: {:?}", payload);
    }
}

// Transmit
let payload = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
for &frequency in transceiver.send(&payload).iter() {
    for &sample in transceiver.generate_beep(frequency).iter() {
        // Play sample
    }
}

Examples

A browser based demo is available at https://unrud.github.io/audio-barcode. The source code can be found in examples/web.

License

MIT (see LICENSE)

Thirdparty libraries

• goertzel
  • Repository: https://github.com/mcpherrinm/goertzel
  • License: MIT
  • Patches:
    • Use f32 samples
    • Optimizations
• reed-solomon-rs
  • Repository: https://github.com/mersinvald/reed-solomon-rs
  • License: MIT
  • Patches:
    • Make Galois Field generic: Add GF(2^3) to GF(2^7)