Lua beats MicroPython for embedded devs

https://www.embedded.com/why-lua-beats-micropython-for-serious-embedded-devs

by willhschmid • 1 year ago

92 84 1 year ago

jacknews• 1 year ago

Lua is just a much simpler language at heart.

Python does have the 'there should be one, preferably only one, way to do it' mantra, but to me it utterly fails at that, and is in fact a bit of a 'kitchen sink' or 'armchair' language.

That is it's strength in some ways, it's easy and approachable, and has more libraries than perhaps any other language, so you can usually get something working fairly quickly.

But it's not so suited to sparse environments. You can't easily turn a plump armchair with automatic footrests and telescoping side-tables into a plywood Eames.

qznc• 1 year ago

Python is easy. Lua is simple.

The problem of "easy" is that it implies hidden complexity for its magic. The problem of "simple" is that it requires more work from its users.

3036e43• 1 year ago

Python also seems to have more issues with stability, in the sense that things randomly stop working when you upgrade from version 3.x to 3.x+1. Lua might not be perfect either, but at least it seems common that a platform supports a range of Lua versions instead of forcing an immediate upgrade.

marky1991• 1 year ago

Could you give some examples?

smohare• 1 year ago

What’s the dev experience actually like for serious Lua? I’ve only used it for some basic neovim configuration. The dynamicism and lack of type hinting in Python that was the norm when I started having to review professional code, after transitioning from pure mathematics, was a major cognitive blocker for me. With a math paper I could typically skim the first few pages to map the author’s particular symbology (if non-standard) and know exactly what was being expressed. I could never do that with untyped code.

unleaded• 1 year ago

Lua can be quite an elegant language once you get to know it well, but you can still use it like most other programming languages, it's not that weird. There are quirks like arrays starting at 1 (and all arrays being hash tables) but they don't take that long to get used to. The real strength is in the ecosystem and implementation itself, it's designed to be easily embedded into applications and there's not really much else like it. Some developers want to incorporate a scripting language into their project and get turned off by Lua's quirks and choose something else, but it usually ends up causing more problems than it was meant to solve.

On typing, there's only a few main ones you need to worry about—strings, functions, tables and numbers. I don't think it does weird things like JS where it converts between them without asking. Luau adds some type hinting if it's a big point of concern but I haven't really looked into it much.

SV_BubbleTime• 1 year ago

There are quirks like arrays starting at 1

I know it’s probably and overreaction, but this was a compete non-starter for me.

pmarreck2• 1 year ago

There are languages that transpile to Lua that get you things like typing…

https://typescripttolua.github.io/

I’m personally a fan of YueScript which is basically an evolution of MoonScript (but it’s not typed).

https://yuescript.org/

LuaJIT has ridiculously easy C interop.

mdkdjdnffn• 1 year ago

What’s the dev experience actually like for serious Lua

The dev experience for lua is f-ing awful.

The language is small, but not “simple”; it’s stuck in 1985.

The tooling is nearly non-existent and the stuff that does exist is a joke.

The few libraries that exist are awful and barely maintained; the maintained libraries are maintained by neckbeards with a god-complex.

The community is “reimplementing everything by hand is the right way to do it AND ALSO you’re an idiot doing it wrong” toxic. There are a million good reasons why it’s only has a foothold in nginx and Roblox territory.

It’s not a joke to say that it’s f-ing terrible all the way around.

docandrew2• 1 year ago

nginx and Roblox and redis and nmap and neovim and cryengine … the list goes on

There are a LOT of tools with embedded Lua scripting capabilities.

giraffe_lady• 1 year ago

8 years of full time professional lua development experience here and unfortunately I agree with all of this. I use fennel when I can; it doesn't improve any of the library or tooling problems but it doesn't make them worse either and addresses several of the problems with the language semantics itself.

hajile3• 1 year ago

Lua was designed in 1993. This was back when MS-DOS was still cutting edge and the 66MHz Pentium was cutting-edge consumer technology.

Even "modern" languages often don't have features like first-class functions, closures, proper tail calls, etc that Lua has had for a very long time now. LuaJIT also trades blows with JS almost certainly making it the fastest or second-fastest dynamic language around.

There's a lot to like about the language (aside from array indexes starting at 1), but I think you are right about the ecosystem and probably right about most of community.

delduca2• 1 year ago

When I decided to create a game engine where the game could be entirely scripted in a scripting language, I was choosing between JavaScript (QuickJS), Python (Boost.Python), and Lua (Sol2).

The ease of embedding Lua, even with a C++ wrapper, is incredible. With little effort, I now have something I consider “ready”.

Not to mention, it’s a very lightweight VM.

https://github.com/willtobyte/carimbo

triknomeister2• 1 year ago

Boost.python is not the best scripting tool to be honest. So, that might affect your judgement as well.

UncleEntity• 1 year ago

I've yet to find an even decent python binding generator, TBH.

Generally, I use pybindgen to get the basic module and then hack on that by hand. The main problem is most C(++) libraries aren't designed to interoperate with managed memory languages so most of the work is figuring that out. Don't get me wrong, I've tried to work within the binding library (with pybindgen at least) but the amount of work for anything even slightly complicated isn't really worth it.

For a project with a major python API (like blender) you're better off crafting your own python class generator (again, like blended does, and even that has some major issues around object lifetime management). Best would be to design the underlying library/application with python integration in mind but that's not always possible if you want to include other libraries.

I can say I did mess around with using lua as an embedded scripting language within an application years ago and it wasn't too difficult from what I remember. It was only ever a proof-of-concept and didn't go too far so I never ran into the inevitable edge case as one always does with these sorts of things.

conaclos3• 1 year ago

Is Sol2 a Lua VM or just a wrapper to the standard Lua VM?

delduca2• 1 year ago

It is a wrapper, in next months it will be also a luau wrapper

3036e43• 1 year ago

A nice thing about seeing an engine or application support Lua for scripting is that it implies Fennel can be used (and transpiled to Lua). Or at least that is highly likely unless something unusually weird is going on.

https://fennel-lang.org/

Palomides• 1 year ago

is anyone "serious" using micropython or lua for embedded work?

qart• 1 year ago

The embedded world is really vast. If it's something safety critical, regulations won't allow it. But the regulations say nothing about all the test rigs you'll be building. IoT is another domain where people do whatever they find convenient.

matt_trentini6• 1 year ago

Yes, we use MicroPython for medical device development up to class B.

5d41402abc4b• 1 year ago

How do you handle memory fragmentation?

xchip4• 12 months ago

Could you give a link to such devices?

zevv3• 1 year ago

I have been developing Lua-heavy embedded products as a freelancer for about 20 years now, including VoIP devices, home automation controllers, industrial routers, digital video recorders, and more. These systems typically consist of a Linux kernel, some libc implementation, the lua interpreter and a few 3d party libs support libs to help building the app. The Lua apps ranges from 30k to 100k lines of code, depending on the application. Some of these devices can be considered 'small' in 2025 terms: 8MB of flash, 64MB of ram. Lua is doing great here.

All of these products are still alive today, actively supported and making my customers good money.

Some things come very natural to Lua: Lua <=> C interfacing is a breeze, and while some modern languages are still struggling to figure out how to do proper async, Lua has been able to do this for decades. The language itself is minimal and simple but surprisingly powerful - a few smart constructs like coroutines, closures and metatables allow for a lot of different paradigms.

For new projects at this scale, I would still choose Lua + C/C++ as my stack. Over the last few years I have been visiting other ecosystems to see what I'm missing out on (Elixir, Rust, Nim), and while I learned to love all of those, I found none of them as powerful, low-friction and flexible as Lua.

conaclos3• 1 year ago

I am currently working on an embedded system with 264Kb of RAM and 4Mb of flash. Do you think Lua could be used in such limited settings? I am also considering the berry scripting language [0].

[0] https://berry-lang.github.io/

mrheosuper• 1 year ago

the article is comparing micropython and lua, so i assume this is about MCU, not embedded linux.

Most of the time you have less than 1MB of ram on MCU

pmarreck2• 1 year ago

there are thousands of products that use Lua underneath or in some capacity. I investigated LuaJIT these past few months and I think it is underrated.

joezydeco• 1 year ago

Define "serious"?

Every so often I have a need for a small cheap device interoperating with a larger system that I'm developing. Like something that sits on MODBUS and does a simple task when signalled. I've taken the RP2040 and Pico board and spun it into a gizmo that can do whatever I want with Micropython, and it's an order of magnitude cheaper and faster than trying to spin it up in STMCube.

jononor2• 1 year ago

Just as one example, MicroPython is deployed in several satellites (cubesats). There are some conference talks and podcasts about it.

rgoulter• 1 year ago

[bolded] Lua isn’t just a high-level language. It’s an embedded dev strategy.

I find it difficult to take any writing seriously when it uses phrases like this.

epcoa• 1 year ago

This is just an ad in a trade rag masquerading as an article or something. It's an ad for that Xedge Lua framework.

stinos2• 1 year ago

The whole article gives me a 'I know LUA and have been using it for years, I also tried MicroPython for a couple of hours, so now I'm ready to draw conclusions' vibe. With some 'Python vs C' on top of it. Not everything written about MicroPython is factually incorrect, but some of the things are so over the top to the point that it becomes ridiculous. Just one example:

MicroPython can be equally readable, but in practice, many projects end up with blurred layers between system code and scripting. That creates a maintenance burden as projects grow.

Yeah, right. Even if this is the case (I find it hard to belive the author has really seen 'many' sort of professional MicroPython projects), where's the proof the language used was the deciding factor in that. And not the project management for instance. Or simply the dev's architecturing abilities.

thomasm6m6• 1 year ago

Much of the article resembles chatgptese... though I suppose for adslop it doesn't matter whether it's written by a human or an llm

AlecSchueler2• 1 year ago

"It isn't just X, it's Y" is textbook ChatGPT.

capyba• 1 year ago

as other commenters noted, this sounds like chatgpt and it gave me indigestion when reading

KaiserPro2• 1 year ago

With respect that sounds like marketing fluff.

You use micrpython when you have lots of horsepower and need something fairly robust on the network.

You use C/C++ if you need precise control over power, memory or CPU. Even though if you're doing network stuff its much harder to do quickly and securely. (THere might be better embedded TLS support now)

Lua is frankly just sparkling C. Sure if someone has create a bunch of libraries for you, then great, if not, you've now go to support lua toolchain, and your own microcontrollers toolchain, and port what ever control lib the manufacturer provides yourself.

Or, as this is a marketing page, pay https://realtimelogic.com/products/xedge/ to do it for you.

Archit3ch• 1 year ago

You use micrpython when you have lots of horsepower

It runs on a 2350.

blackguardx• 1 year ago

Cortex-M33s are decently powerful in the non-Linux embedded world. Micropython isn't competing with Linux, it is competing with bare-metal code.

KaiserPro2• 1 year ago

the 2350 is huge compared to an STM8, or atmega.

rasz• 1 year ago

2350 with PSRAM is more powerful than top of the line 1997 PC.

analog312• 1 year ago

Is there a way to try out embedded Lua within the Arduino dev environment? Yeah I know, friends don't let friends, but I'm still curious.

7thaccount• 1 year ago

Actually I haven't heard this. Does Arduino have a bunch of controversy now?

analog312• 1 year ago

It evokes the "real engineers don't use it" reaction, similar to any tool that's perceived as being of primary interest to hobbyists and students.

Some concerns are valid: Arduino doesn't have as much flexibility for digging really deep into things like pin and memory assignments and what happens when a microcontroller starts up. Also, the quality and documentation of Arduino support can vary from one MCU family to another.

There's a concern about the quality of libraries and code.

It doesn't support hardware debugging.

Granted, the embedded community has good reasons for being conservative, especially for critical applications.

theoutfield• 1 year ago

Another scripting language that I’ve been using in embedded systems with a little more memory is AngelScript. It’s underrated in this space. It’s very easy to extend and has the advantage of being a subset of C/C++.

skybrian• 1 year ago

As a hobbyist I just use Arduino (via platformio). I don't think I need an interpreter of any sort for microcontrollers because recompiling and uploading the flash on hobbyist boards is quick and easy.

But I'd like to try some other compiled language someday because I'm not a big fan of C++. Any recommendations for something that works well with a Raspberry Pi Pico?

Rebelgecko• 1 year ago

I'm not an expert but from what I've seen Rust is one of the big alternatives. It's new enough to be trendy and fixed a lot of C++ issues whole being mature enough that the tooling is ok.

I'm also intrigued by Zig. I haven't used it for anything yet but the language looks fun and I believe platform.io supports it

Raspberry Pis are beefy enough that you could also get away with less systems-y languages. I like Kotlin. By default Kotlin needs a JVM but I think it's usable if you build native executables. However if you want to fiddle with GPIOs you might have to do it by manually setting things on/off in the filesystem (edit, sorry, just read you're using a PICO. Not sure how well Kotlin is supported)

20after4• 1 year ago

The Pi Pico is a microcontroller, not a full linux-capable SBC. The confusion is helped by the fact that Raspberry Pi has a bunch of variants and almost all of them are SBCs.

miguel_martin2• 1 year ago

Nim is a likely a pretty good option, see https://github.com/EmbeddedNim/picostdlib/tree/master

jacobgorm• 1 year ago

Toit from the v8 devs is also pretty cool.

jokoon• 1 year ago

I dislike how the syntax of lua feels, maybe the same for its semantics

gdscript is so awesome

ycombinatrix• 1 year ago

"Serious embedded devs" are probably using a compiled language.

Dork12342• 1 year ago

Well it is compiled into Bytecode.

jononor2• 1 year ago

Lua is a great language, including for embedded. And I am sure that their Lua-based product is good also. But this article was not very convincing as to why it "beats MicroPython". The criticisms are vague or not correct. Extending MicroPython in C is quite easy, and one can implement third party modules in the same way all the official modules are made. There is build variable to set for including that into your custom firmware build - nothing particularly tricky about it. The article goes on to lament that popular libraries from Python world are not available, including numpy. But actually there is a very good reimplementation of numpy (and parts of scipy), called ulab.

10000truths• 1 year ago

It's important to distinguish between "embedded" as in platform, and "embeddable" as in "integrate into existing application". MicroPython is used in embedded platforms, yes, but it's not an embeddable runtime like Lua. MicroPython is designed to replace the traditional C runtime with a Python one. The expected use case is to have a minimal C shim that initializes MicroPython, then define the rest of your business logic as a MicroPython script. There's no equivalent of lua_State that allows you to run multiple MicroPython interpreters concurrently in your program. There's no sandboxing functionality for running untrusted user scripts containing "while True: continue" or "oom = 'a'*(10**40)'. MicroPython doesn't solve the "I want rapid iteration with scripts in my game engine" problem, it solves the "I want to read the temperature sensor on my IoT board using Python" problem.

stinos2• 1 year ago

it's not an embeddable runtime like Lua

While it's true you can't have multiple MicroPython interpreters running concurrently (or at least not easily; it's not that the design makes this impossible, it's just that all in all MicroPython is fairly young and development focus has been put elsewhere), it is possible to embed MicroPython. Not completely out of the box, needs some glue code etc. See for example https://github.com/micropython/micropython/tree/master/ports....

1vuio0pswjnm7• 1 year ago

https://pldb.io/lists/top1000.html

Lua ranks higher than MicroPython in this list

https://www.farginfirmware.com/home/lua-vs-micropython

Github account "SkipKaczinksi" thinks Lua is generally faster

https://hackaday.com/2020/11/14/micropython-on-microcontroll...

Hackaday commenter "Michael Polia" suggests Lua, smaller, faster

https://www.cnx-software.com/2021/11/28/toit-open-source-lan...

Toit scripting language claims to be 30x faster than MicroPython

Toit founder was "responsible for initial development of V8"

xchip4• 1 year ago

The problem with Micropython is that they don't have unit tests for the features they implement, so they keep breaking things over and over, or fix something but brake something else.

matt_trentini6• 1 year ago

Unit test coverage is exceptionally high for the interpreter, and always has been:

https://micropython.org/resources/code-coverage/

('py' folder: 99.2% line, 88.7% branch coverage)

Testing the port-specific code has been a much more challenging problem.

Which is why in the past year or two there's been a lot of energy put in to HIL testing. There are now a few dozen boards that are automatically tested with an increasingly rich suite of hardware tests. Both the number of boards and tests are increasing rapidly.

It's not perfect but it's getting pretty darn good. If you want to help out please do reach out.

xchip4• 1 year ago

Then why do they have 1300 issues open? Good luck to you but it looks like a land mine to me. They are 420 pull requests not merged, so that is a lot of disappointed developers.

They need to test the whole ecosystem, that is the usual interaction with typical peripherals (I2C, I2S, SPI, Serial, interrupts...) and for every bug fixed there should be a unit test to make sure future changes don't cause regressions.

I had this conversation with them but they take every opportunity to justify/ask for more funding.

They are also prioritizing adding support for new chips but they quickly get eaten alive by chaos, regressions and platform fragmentation.

Lua beats MicroPython for embedded devs

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