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node-libgpiod

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Native nodejs bindings for [libgpiod][libgpiod]

github.com/sombriks/node-libgpiod

sombriks/node-libgpiod

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# Development Whenever someone needs to modify or enhance something in libgpiod, a few things must be done to prepare the development environment for it. ## Environment setup To consume the library all it takes is to have node and libgpiod itself, just as described in the [README][README]. To extend it, however, you need to know better the libgpiod provided by the target platform. ### A tale of fragmentation So far, there is at least 3 big releases to be aware of: - [gpiod 1.4][gpiod-1.4] - [gpiod 1.6][gpiod-1.6] - [gpiod 2.0][gpiod-2.0] The 1.5 version introduced new functionality still present in 1.6, 1.4 can be considered the last in the "old" libgpiod still present on many systems out there. I decided to give up 1.4 series for now. The 2.0 is a brand 'new' (several years old now) API with a very distinct way to work with chips and lines and requests. ### Your openSUSE Tumbleweed daily driver might not be suitable for that work Modern linux desktop is already shipping gpiod 2.x series, but node-libgpiod is still under development. It might be a bit challenging proper setup the system to compile against an older libgpiod version. Currently my recommendation is to setup a reasonable recent linux distro with the proper gpiod version being worked on (1.6). I have a **Fedora 38** virtual machine just for that purpose at the moment, but i am thinking on other ways to work around this version issue. ## Testing Proper test is another challenge. You see, the [examples project][examples] exists because back then i had the time and the hardware to test it, but not the experience to write proper unit and integration tests involving this. But if the kernel module maintainer [wrote 100% software tests][gpiod-2x-test], so can we! I hope so. ### Mocking and simulating There are two tools, two kernel modules, to help us on that endeavor: [gpio-mockup][gpio-mockup], being discontinued, and [gpio-sim][gpio-sim], the maintained one. There is [this thread][reddit-lead] and good [reference material][examples-native] to get started with. The fedora 38 setup offers node libgpiod 1.6.4 and gpio-sim, which is a good combo for 1.x series. But it's an EOL'ed distro, so some alternative must be worked on in near future in order to keep 1.x going on. [README]: ../README.md [gpiod-1.4]: https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/log/?h=v1.4.x [gpiod-1.6]: https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/log/?h=v1.6.x [gpiod-2.0]: https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/log/?h=v2.0.x [examples]: https://github.com/sombriks/node-libgpiod-examples [gpiod-2x-test]: https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/tree/tests/gpiod-test.c?h=v2.0.x [gpio-mockup]: https://docs.kernel.org/admin-guide/gpio/gpio-mockup.html [gpio-sim]: https://docs.kernel.org/admin-guide/gpio/gpio-sim.html [reddit-lead]: https://www.reddit.com/r/raspberry_pi/comments/1aygn6h/comment/l3jn5ir/ [examples-native]: https://github.com/starnight/libgpiod-example