How to write a great Arduino library | Hacker News Reader

How to write a great Arduino library

sparkfun.com

70 pointsapple4ever29 comments

Does anyone have recommendations for writing Arduino code without the Processing-based Arduino IDE? I'm sure there must be a not-too-difficult makefile-based compile/upload configuration, but I'm not aware of any (nor do I trust myself to write one from scratch).

At this point, the Arduino IDE is my least favorite part of the whole ecosystem.

I use PlatformIO's CLI, which is pretty good for build management. It also has its own library system.

Arduino has recently modularised their IDE, and the arduino-cli can be used to crate a sketch, compile it and flash the board: https://github.com/arduino/arduino-cli

I've managed to setup Code::Blocks[0] to use WinAVR to program Arduinos. Here's a guide[1] I found for that. It works, but I probably forgot to add some optimization flags, because the code ran slower than when compiled with the Arduino IDE.

And then I realized, you can just take any .c or .cpp written for the AVR, rename it to .ino, put it in a folder with the same name, and use the Arduino IDE to compile and flash.

So I never really use C::B for the Arduino anymore, I just write the code in Notepad++[2] and use the Arduino IDE to upload.

[0]: http://www.codeblocks.org/

[1]: https://uetianblogger.blogspot.com/2015/05/winavr-and-codebl...

[2]: https://notepad-plus-plus.org/

EDIT: > you can just take any .c or .cpp file

Eh... actually only .cpp, as the Arduino IDE is C++. Or a .c file that will also compile in C++.

Platformio[0] is probably the best option, here.

It supports the arduino-style code munging, though realistically if you're at least remotely familiar with C++ it's super easy to not use it.

It also supports basically every embedded platform out there to some extent.

[0]: https://platformio.org/

Atmel Studio. It was very easy to set up, and can call AVRdude for uploading. It has the ability to import typical Arduino projects, so you can either keep using the Arduino libraries or convert the project to pure C/C++.

I really wanted to use Atmel Studio, but couldn't get it working correctly on Arch Linux + wine. Can't imagine why such a major company wouldn't support Linux native.

The Arduino IDE has a verbose mode which prints out all the commands it uses to upload your program.

This plus VS Code and CMake is what I'd use to start any new project, saves time having to figure out all the options yourself.

I switched to VS Code with the PlatformIO extension. A little bit of conversion is required, 'ino' to 'cpp' and some shuffling between directories.

As others mentioned, PlatformIO is a good start.

For those who are interested in building a library, here's my TravisCI workflow for unit testing & running examples on various platforms: https://github.com/FortySevenEffects/arduino_midi_library/bl...

PlatformIO plugin for VSCode. There's a bit of a learning curve, especially for folder structuring requirements, but overall it makes you stay organized in a consistent and repeatable way. It's also great if you're working with more than just Arduino framework (Espressif, Kendryte, STM32), as you can keep your code modular and easily apply it to different microcontrollers.

I wrote a very, very simple Makefile awhile back utilizing the arduino CLI options.

https://github.com/mcastorina/laptop-remote/blob/master/Make...

Haven't used it since then, so YMMV.

I had good luck with Atmel Studio which is a variant of MS visual studio. This was on the ARM based arduino parts. It overwrote the arduino boot loader. The debugger was actually useful!

I've used this in the past to get started.

https://github.com/mkleemann/cmake-avr

My understanding is that GCC can cross-compile to Arduino if you target AVR. See also https://www.arduino.cc/en/Reference/UsingAVR

I haven't done it personally... but I also haven't yet poked much into Arduino either. I'm still having fun with Raspberry Pis. Arduinos... are a little more in-depth.

Not Fritzing.

Generally: Arduino CLI

Mac + Xcode: EmbedXCode.

Windows: Arduino add-on for VS.

I would keep the Arduino IDE because no work-alike is going to have every feature.

I don’t know if this is what you’re looking for but I frankenstiened this from some stuff on the net: https://github.com/dstutman/avr-template

I have used emacs on linux before and it's fine. However I don't know how well it works with non standard arduinos like atttiny. I can't remember the exact write-up I used but I just googled emacs arduino.

https://marketplace.visualstudio.com/items?itemName=vsciot-v...

I used to rely on this Makefile template https://github.com/sudar/Arduino-Makefile.

Likewise, I use https://github.com/plerup/makeEspArduino

One thing I've learned from maintaining an Arduino library [1] for the last 10+ years: make the API as simple as possible. Lots of people discover programming with Arduino, making the experience enjoyable for them requires abstracting a lot of things away.

Things can be as complex as reasonable in the implementation, but providing helpers, macros & shortcuts (as well as good documentation and examples as stated in the blog post) makes the learning curve less steep.

[1] https://github.com/FortySevenEffects/arduino_midi_library

> Efficiency is not paramount; readability is

How I wish that this would drive C++ design decisions of lately.

How about write in C, rather than C++, so you don't force C++ on your users. I mean, if you're going to go so far as to recommend avoiding pointers in your api because your users can't understand them, why in the hell would you then go write a library in C++?

Using values everywhere has less gotchas in c++ - return value optimization is applied much more consistently for instance.

Also you can make c++ look not far from python in terms of cognitive overhead for beginners. C ? Not so much

In C return value optimization is not a problem to begin with. There are many more side effects in C++ that could inhibit (have inhibited) return value optimization, by e.g. overloading operators. The standard actually changes the behavior of side effects to allow for return value optimization, i.e. code acts differently depending on whether it's return value optimized or not. I don't feel like any of this is consistent or simpler than C.

> In C return value optimization is not a problem to begin with

of course it is - https://gcc.godbolt.org/z/welWvd

C gives you O(N) memcpy, C++ gives you O(1) do-stuff-in-place for the exact same code

> overloading operators

has exactly zero things to do with RVO

> I don't feel like any of this is consistent or simpler than C.

it produces vastly simpler user code. In years and years of programming in C++ never has "code acts differently depending on whether it's return value optimized or not" been an issue for anyone I know.

Because it is safer than using plain old C, which WG14 refuses to improve its security story.

I don't like my IoT devices to be easily p0wned, just because an array went out of bounds.

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