RTLjs

Node.js interface for librtlsdr, using FFI-NAPI

Works with modern versions of node (v14-16 etc.), unlike alternate packages on NPM

Only tested on Linux, but if you ask me, I can very easily add windows/macos support.

Installation

Prerequisites

This module requires librtlsdr. This package in turn requires libusb.

Librtlsdr is a package on most package repositories.

Linux:

sudo apt-get install librtlsdr-dev

Windows:

you will need to install librtlsdr on your machine. DLLs are availble on the librtlsdr wiki. These will need to be inserted into a system path folder so that ffi-napi can access them.

Package

npm i rtljs

Usage

The package is written in ts and compiled to js, so ts typings are automatically provided with the package.

Using ES:

import * as rtljs from "rtljs";

Node require():

const rtljs = require("rtljs");

Sample Usage:

console.log(rtljs.getDeviceCount()); // 1
console.log(rtljs.getDeviceName(0)); // Generic RTL R820T2

let device = rtljs.open(0);
device.setCenterFreq(1090 * rtljs.mhz); // 1090000000

// raw IQ data
device.resetBuffer(); // reset buffer to prevent communication data from appearing as radio data
let data = device.readSync(512); // read 512b
console.log(JSON.stringify(data)); // [128, 127, 128... etc

rtljs.close(device);

Common Fixes

Nothing happening when i use readSync/Async, program just hangs

remember to use device.resetBuffer() before using read commands

Can't access device

you probably forgot to use close() in your code to end the device when the program ended. Reset your usb ports and this should now work fine.

API

TSDoc API available at https://arkanic.github.io/rtljs/

Examples are available here

Broken Stuff

Easy Fixes:

• There are no bias functions at the moment

??wtf??:

• cancelAsync refuses to work, likely some obscure multithreading error with ffi-napi (which happens to hate multithreading)

About

Made by Arkanic

MIT License