About:

timestampSDR is designed to take the UDP stream output from certain SDR receiver software (currently GQRX and rtl_fm) and record transmissions to time-stamped .wav files, discarding silence. This can allow you to quickly review transmissions that occurred over a long period of time.

• ✔️ Works on Linux running GQRX or rtl_fm
• ✔️ Works on Windows 10 running GQRX via pothosSDR
• ❔ Should work on MacOS, but not tested (seeking feedback!)

Getting started:

• Must have node.js installed.
• Clone this repo, or download it and extract the zip file.
• Navigate to the program directory and run npm install to install the program dependencies.
• Refer to the wiki for instructions on setting up your SDR receiver software. Currently this includes GQRX and rtl_fm. GQRX is more user-friendly and seems to provide better audio, rtl_fm runs efficiently on low-spec devices.
• Regardless of your receiver software, make sure your squelch is adjusted well. timestampSDR cannot differentiate static from meaningful transmissions.

Usage:

node main.js [options]
--timeout     | After transmission, wait <timeout> seconds before saving/deleting file and moving on | DEFAULT: 5
--minDuration | After timeout, if recording was less than <minDuration> seconds, file is deleted     | DEFAULT: 5
--maxFiles    | Number of files to save before exiting program                                       | DEFAULT: 5
--dateFmt     | Date formatting: "datetime", "unix", or custom moment.js format                      | DEFAULT: "datetime"
--sampleRate  | Input sample rate in Hz                                                              | DEFAULT: 48000
--host        | Local IP address serving data                                                        | DEFAULT: "127.0.0.1"
--port        | Local UDP port serving data                                                          | DEFAULT: 7355
-p            | Print options used and source they were chosen from (CLI, config file, default)      |

Note:

• Recordings are saved in the recordings subdirectory in the main program directory.
• Timeout resets if a new transmission comes in before timeout finishes.
• Silence is not recorded, and doesn't count towards minDuration.
• To set your own default options (which can be overridden by passing in arguments), you can modify config.js.