Automatically optional too, simply by testing for the presence of the library, avoiding making the user pass arguments or define environment variables or the like.
I'm working on making a Raspberry Pi project of mine, a project that depends on GPIO, compatible with the Raspberry Pi 5. (The Raspberry Pi 5, in general, has caused a lot of grief due to a new GPIO chipset.)
Having reached the point where I'd solved all of my own GPIO issues, I had left to handle one library of someone else's in need of upgrade. I could, of course, just take my own fork of their project and go my own merry way now that I have working code, but I'd like to offer what I've done as a pull request.
There's one thing now that could be a sticking point, however, which I'd like to avoid if possible. I've introduced a new dependency on the libgpiod library.
I'm pretty sure the original author wouldn't want to deal with that. I'd like for this new code to compile on a Raspberry Pi 3 or 4 without libgpiod having been installed, but take full advantage of libgpiod if present.
Here's my binding.gyp file:
Here's the start of my abstract-gpio.cpp:
My C++ skills are rusty at best. Until now I hadn't touched my own C++ code for five years, and five years ago I hadn't touched C++ for well over a decade.
node-gyp? I've merely followed examples and simple recipes at this point.
The big trick is that consumers of this library will use this library via npm install node-dht-sensor. I don't want the user to have to worry about libgpiod unless they're using a Raspberry Pi and have a good reason to install it.
I might be able to settle for something like npm install node-dht-sensor --use_libgpiod=true, but I hope I can do better.
Is there some combination of node-gyp options and perhaps, if needed, dummy libgpiod C++ stubs (that won't interfere with the real libgpiod if present) that can solve this problem for me?
I'm working on making a Raspberry Pi project of mine, a project that depends on GPIO, compatible with the Raspberry Pi 5. (The Raspberry Pi 5, in general, has caused a lot of grief due to a new GPIO chipset.)
Having reached the point where I'd solved all of my own GPIO issues, I had left to handle one library of someone else's in need of upgrade. I could, of course, just take my own fork of their project and go my own merry way now that I have working code, but I'd like to offer what I've done as a pull request.
There's one thing now that could be a sticking point, however, which I'd like to avoid if possible. I've introduced a new dependency on the libgpiod library.
I'm pretty sure the original author wouldn't want to deal with that. I'd like for this new code to compile on a Raspberry Pi 3 or 4 without libgpiod having been installed, but take full advantage of libgpiod if present.
Here's my binding.gyp file:
Code:
{ "targets": [ { "variables": { "dht_verbose%": "false" }, "target_name": "node_dht_sensor", "sources": [ "src/bcm2835/bcm2835.c", "src/node-dht-sensor.cpp", "src/dht-sensor.cpp", "src/util.cpp", "src/abstract-gpio.cpp", // <-- My code to handle GPIO using either bcm2835 or libgpiod ], "include_dirs": [ "<!@(node -p \"require('node-addon-api').include\")" ], "dependencies": [ "<!(node -p \"require('node-addon-api').gyp\")" ], 'libraries': [ '-lgpiod' // <-- New dependency ], "defines": [ 'NAPI_DISABLE_CPP_EXCEPTIONS' ], "conditions": [ ["dht_verbose=='true'", { "defines": [ "VERBOSE" ] }] ] } ]}Code:
#include "abstract-gpio.h"#include <algorithm>#include "bcm2835/bcm2835.h"#include <fstream>#include <gpiod.h> // <-- What to do here to make this optional? Can node-gyp#include <regex> // conditionally create a symbol for #ifndef-ing here?#include <stdio.h>#include <string>node-gyp? I've merely followed examples and simple recipes at this point.
The big trick is that consumers of this library will use this library via npm install node-dht-sensor. I don't want the user to have to worry about libgpiod unless they're using a Raspberry Pi and have a good reason to install it.
I might be able to settle for something like npm install node-dht-sensor --use_libgpiod=true, but I hope I can do better.
Is there some combination of node-gyp options and perhaps, if needed, dummy libgpiod C++ stubs (that won't interfere with the real libgpiod if present) that can solve this problem for me?
Statistics: Posted by kshetline — Fri Feb 14, 2025 1:08 am — Replies 1 — Views 53
