Squish That Stack With Rampart

November 24, 2022 by Dave Rowntree 18 Comments

[P B Richards] and [Aaron Flin] were bemoaning the resource hunger of modern JavaScript environments and planned to produce a system that was much stingier with memory and CPU, that would fit better on lower-end platforms. Think Nginx, NodeJS, and your flavour of database and how much resource that all needs to run properly. Now try wedge that lot onto a Raspberry Pi Zero. Well, they did, creating Rampart: a JavaScript-based complete stack development environment.

The usual web applications have lots of tricks to optimise for speed, but according to the developers, Rampart is still pretty fast. Its reason for existence is purely about resource usage, and looking at a screen grab, the Rampart HTTP server weighs in at less than 10 MB of RAM. It appears to support a decent slew of technologies, such as HTTPS, WebSockets, SQL search, REDIS, as well as various utility and OS functions, so shouldn’t be so lightweight as to make developing non-trivial applications too much work. One interesting point they make is that in making Rampart so frugal when deployed onto modern server farms it could be rather efficient. Anyway, it may be worth a look if you have a reasonable application to wedge onto a small platform.

We’ve seen many JavaScript runtimes over the years, like this recent effort, but there’s always room for one more.

The Fastest Fourier Transform In The West

November 23, 2022 by Dave Walker 22 Comments

An interesting aspect of time-varying waveforms is that by using a trick called a Fourier Transform (FT), they can be represented as the sum of their underlying frequencies. This mathematical insight is extremely helpful when processing signals digitally, and allows a simpler way to implement frequency-dependent filtration in a digital system. [klafyvel] needed this capability for a project, so started researching the best method that would fit into an Arduino Uno. In an effort to understand exactly what was going on they have significantly improved on the code size, execution time and accuracy of the previous crown-wearer.

A complete real-time Fourier Transform is a resource-heavy operation that needs more than an Arduino Uno can offer, so faster approximations have been developed over the years that exchange absolute precision for speed and size. These are known as Fast Fourier Transforms (FFTs). [klafyvel] set upon diving deep into the mathematics involved, as well as some low-level programming techniques to figure out if the trade-offs offered in the existing solutions had been optimized. The results are impressive.

Fastest FFT code benchmarking results in ms — Benchmarking results showing speed of implementation versus the competition (ApproxFFT)

Not content with producing one new award-winning algorithm, what is documented on the blog is a masterclass in really understanding a problem and there are no less than four algorithms to choose from depending on how you rank the importance of execution speed, accuracy, code size or array size.

Along the way, we are treated to some great diversions into how to approximate floats by their exponents (French text), how to control, program and gather data from an Arduino using Julia, how to massively improve the speed of the code by using trigonometric identities and how to deal with overflows when the variables get too large. There is a lot to digest in here, but the explanations are very clear and peppered with code snippets to make it easier and if you have the time to read through, you’re sure to learn a lot! The code is on GitHub here.

If you’re interested in FFTs, we’ve seen them before around these parts. Fill your boots with this link of tagged projects.

Two Esoteric Programming Languages, One Interpreter

November 19, 2022 by Elliot Williams 9 Comments

Many of you will have heard of the esoteric programming language Brainf**k_. It’s an example language that’s nearly impossible to use because it’s too simple. It’s basically a Turing computer in code – you can essentially put characters into an array, read them out, increment, decrement, and branch. The rest is up to you. Good luck!

What could be worse? Befunge, a language that parses code not just left-to-right or top-to-bottom, but in any direction depending on the use of ^, v, >, and <. (We love the way that GOTO 10 looks like a garden path in the example.)

Uniting the two, [rsheldiii] brings us BrainFunge, a Brainf**k_ interpreter written in Befunge. And surprisingly, the resulting write-up sheds enough light on both of the esoteric programming languages that they make a little bit of sense. If you try to read along, you’ll definitely be helped out by Esolang Park, which was new to us, and accommodates the non-traditional parsing while displaying the contents of the stack.

If you get a taste of the esoteric, and you find that you’d like a little more, we have a great survey of some of the oddest for you. After cutting your teeth on Befunge, for example, we bet you’ll be ready for Piet.

Blender Builds LEGO Models

November 15, 2022 by Bryan Cockfield 13 Comments

Blender is a free and open source computer graphics package that’s used in the production of everything from video games to feature films. Now, as demonstrated by [Joey Carlino], the popular program can even be used to convert models into LEGO.

This new feature available in Blender 3.4 allows for the use of instance attributes in a way that a large number of points on a model can be created without causing undue strain on (and possible crashing of) the software. Essentially, an existing model is split into discrete points at specific intervals. The spacing of the intervals is set to be exactly that of LEGO bricks, which gives the model the low-resolution look of a real LEGO set. From there, a model brick is created and placed at each of these points, and then colors can be transferred to the bricks individually.

The demonstration that [Joey] uses is converting a beach ball model to LEGO, but using these tools on other models delivers some striking results. He goes over a lot of the details on how to create these, and it would only be a short step from there to ordering the bricks themselves. Or, using these models and sending them over to a 3D printer straight from Blender itself. Not bad for free software!

Continue reading “Blender Builds LEGO Models” →

Screenshot of the Arduino Lab for MicroPython

Arduino Brings A MicroPython IDE

November 14, 2022 by Arya Voronova 52 Comments

Both Arduino and MicroPython are giants when it comes to the electronics education area, and each one of them represents something you can’t pass up on as an educator. Arduino offers you a broad ecosystem of cheap hardware with a beginner-friendly IDE, helped by forum posts explaining every single problem that you could and will stumble upon. MicroPython, on the other hand, offers a powerful programming environment ripe for experimentation, and doesn’t unleash a machine gun fire of triangle brackets if you try to parse JSON slightly incorrectly. They look like a match made in heaven, and today, from heaven descends the Arduino Lab for MicroPython.

This is not an Arduino IDE extension – it’s a separate Arduino IDE-shaped app that does MicroPython editing and uploads code to your board from a friendly environment. It works over a serial port, and as such, the venerable ESP8266-based boards shouldn’t be be left out – it even offers file manager capabilities! Arduino states that this is an experimental effort – it doesn’t yet have syntax checks, for instance, and no promises are made. That said, it already is a wonderful MicroPython IDE for beginner purposes, and absolutely a move in the right direction. Want to try? Download it here, there’s even a Linux build!

High-level languages let you build projects faster – perfect fit for someone getting into microcontrollers. Hopefully, what follows is a MicroPython library manager and repository! We’ve first tried out MicroPython in 2016, and it’s come a long way since then – we’ve seen quite a few beginner-friendly MicroPython intros, from a gaming handheld programming course, to a bipedal robot programming MicroPython exploration. And, of course, you can bring your C libraries with you.

Dial-Up Internet Over WhatsApp

November 13, 2022 by Matthew Carlson 42 Comments

As we returned from Supercon 2022, we noticed many airlines offer free in-flight messaging. While the messages are handy for complaining about the seat size, it isn’t quite as exciting as access to the internet. In the air, we wondered how hard it would be to tunnel an internet connection over messaging. Funny enough, [Aleix Rodríguez Alameda] has a project that does exactly that by tunneling traffic over Whatsapp.

In [Aleix]’s case, cell carriers are pretty stingy with internet data when traveling in South America but often give unlimited WhatsApp data. So, ahead of time, two accounts are set up. A server is on one account and acts as a proxy to the broader internet and listens to messages to the server account. Then when in a restricted access setting, the client connects with a WebSocket and sends messages. The real trick for turning the WhatsApp messages into an internet connection the client can use is exposing a port from a local nodeJS web server. It connects to the WhatsApp API through a WebSocket and then acts as a proxy. Then, you set up traffic to be redirected through that port with curl or Firefox.

Packets are split to prevent you from sending too many messages, as in their testing, [Aleix]’s accounts were banned quickly. You shouldn’t expect massively fast speeds, as 300kbps was pretty typical during testing, which according to Wikipedia, is about what dial-up got with V.44 compression.

Which is around the same speed as TCP/IP tunneled over NRF23L01 radios.

The demo toot screenshot, showing a text-only message sent from the ESP32 using the library.

Moved Off Twitter? Make Your ESP32 Toot

November 9, 2022 by Arya Voronova 75 Comments

Since Twitter was officially taken over by Elon Musk a few days ago, there’s been significant staff cuts, a stream of questionable decisions, and uncertainty about the social media platform’s future. So it’s little surprise that a notable number of people, those in the tech and hacker scenes in particular, have decided to move over to (or at least bridge their accounts with) the distributed and open source Mastodon service.

Of course, the hacks would follow closely, and [Toby] shares a simple ESP32-based Mastodon client library for us to start with. Instead of “tweets”, messages on Mastodon instances are called “toots”, in line with the platform’s mammoth-like mascot. The library, called Luyba, is able to send toots and includes a demo firmware. Built using C++ and with support for Platform.IO, it should fit into quite a few projects out there, letting you easily send toots to whichever instance you find your home, as the library-aided demo toot shows.

What could you do with such a library on your MCU? Turns out, quite a few fun things – a home automation interface, a critter trap, an online BBC Basic interpreter, or, given image support, a camera that tweets whatever it’s pointed at. There’s quite a bit of fun hackers can have given a micro-blogging service API access and a bit of code that works with it. That said, for all the good that Twitter brought us over the years, there’s a lot that Mastodon can easily do better, between easily game-able “Trending” sidebar, bias found in auto-cropping algorithms and disarrayed internal security policies.