NodeJS bindings for lg

This package provides NodeJS bindings for the lg GPIO library.

Disclaimer

This is my first time writing native Node bindings for a C library. Heck, it's my first time writing any C/C++ code! So if things don't work as expected, or if the bindings leak memory like nobody's business, please don't be too hard on me. I'll be happy for any issue reports and / or pull requests.

Prerequisites

You need to have the lg library installed on your system. Since the library doesn't compile outside Linux, this might complicate things slightly. This package can be installed anywhere, but the bindings themselves will only be compiled on Linux to prevent npm install from dying all the time. This should enable you to develop on your local machine regardless of platform or architecture and run the code on machines which actually have GPIO for the underlying library to work with.

On a Raspberry Pi the lg library is easily downloaded, compiled and installed in three commands. Refer to the library website for the how-to.

Installation

npm install --save lgpio

Docs

The API documentation is autogenerated from the (pretty extensive) JSDocs which are present in the included TypeScript declaration files. Most of the documentation is copied verbatim from the lg library docs, only altered where it makes sense.

About

The bindings are mostly 1:1 with the underlying C functions, except the lg prefix is stripped from the function names (you'll usually want to import * as lg anyway). The call signatures are mostly kept identical, except for obvious differences:

• All functions which indicate an error by returning a negative integer value throw an error instead; this means all functions whose return value only signifies success or failure return void in JS.
• Passing array length separately from the array itself (as you need to do in C) is unnecessary in JS, so the array length / count parameters are omitted where applicable.
• Some parameters can be omitted and fall back to sane defaults (like the initial output level of a GPIO, which defaults to low).