Rattlegram icon

Rattlegram - SMS via audio! for Android

1.13 0BSD

Transmit short text messages over COFDMTV encoded audio signals

Download APK (5.3 MB)
Description Messaging Old Versions
Rattlegram screenshot 0 Rattlegram screenshot 1 Rattlegram screenshot 2 Rattlegram screenshot 3 Rattlegram screenshot 4
Version
1.13 (14)
Update
Developer
aicodix GmbH
Category
Messaging
License
0BSD
Source Code
Code Repository

Rattlegram app

Rattlegram is Messaging tool that is open source under the 0BSD license.

Rattlegram lets you transmit short text messages over COFDMTV encoded audio signals. COFDMTV is based on COFDM (coded orthogonal frequency-division multiplexing) technology:

  • 160 ms long OFDM symbols
  • 6.25 Hz per sub-carrier
  • 1/8 guard interval
  • differentially encoded PSK (phase-shift keying) modulation
  • systematic polar codes for forward error correction

Currently Modes 14, 15 and 16 are supported: Using either SPC(2048, 1392), SPC(2048, 1056) or SPC(2048, 712) with CRC32C aided SCL decoding and differential QPSK modulation for the payload. Only a bandwidth of 1600 Hz is needed and the transmission of either 85, 128 or 170 bytes take about one second with the leading noise and fancy header disabled.

Old Versions