Tech blog on web, security & embedded

Let me introduce myself, I'm Dion Dokter, 24 years old (as of writing) and the newest member at Tweede golf (TG). I've always been into computers and started writing desktop software and games in 2013, embedded software in 2015, and started with Rust in 2019.

In our last post, we've seen that async can help reduce power consumption in embedded programs. The async machinery is much more fine-grained at switching to a different task than we reasonably could be. Embassy schedules the work intelligently, which means the work is completed faster and we race to sleep. Our application actually gets more readable because we programmers mostly don't need to worry about breaking up our functions into tasks and switching between them. Any await is a possible switching point. Now, we want to actually start using async in our programs. Sadly there are currently some limitations. In this post, we'll look at the current workarounds, the tradeoffs, and how the limitations might be partially resolved in the near future.

Previously we talked about conserving energy using async. This time we'll take a look at performing power consumption measurements. Our goal is first to get a feel for how much power is consumed, and then to measure the difference between a standard synchronous and an async implementation of the same application.

Most of our web applications use either Node.js or Symfony for their server-side part. Both offer a lot in terms of productivity. But every now and again, when you look at the computing power used or the amount of time a simple HTTP request takes, you can't help to think "what if..?".

Sending documents over the internet can be a pain. Email providers generally support attachments with a maximum size between 10 and 50 MB, for larger files one would need to find another way. Most people would probably use one of the many public cloud or file sender solutions. But what if the files to be sent contain personal information, medical information or are private family photos? And how do you know that only the recipient can access and download these files?

To more effectively write Embedded Rust applications, we want a clearer picture of two aspects: how can we ergonomically perform multiple tasks concurrently, and how can we exploit low-power modes to save energy. In the coming weeks, we want to write a small but non-trivial application that communicates with 2 sensors, uses async, and uses the low-power modes to conserve energy.

In embedded systems, energy efficiency is crucial for practical applications. Usually devices run on a battery, so the less energy you use, the longer the power supply will last. In this post we'll look at the basics of going to sleep and waking back up, and build a proof of concept using the nRF52840 development kit.

As owner and technical lead of our company I'm very motivated to keep up to speed with all new developments and to continuously innovate our tech stack. Nevertheless, every once in a while I find myself lacking in in-depth, hands-on experience in languages and tools I really want to be on top of. At that moment, I know I need to hit pause and take the time for a deep dive, in the form of a personal learning project.

David is Tweede golf's newest addition, and not just any addition, he combines his work as a software engineer with a PhD in theoretical high energy physics. Specialized in the field of privacy and security, David brings a lot of knowledge to the team. For 2021 we were on the look-out to strengthen our expertise in this domain. David joining the team is just that!

Welcome to the age of communication. It's 2021 and technology has come a long way. People, large machines and small devices communicate more intensively than ever before, and many technologies to enable them to do so have been developed. Some of those technologies use physical pathways like fibreglass to reach their receivers, others use radio signals to send messages. It's these wireless communication technologies that spark the imagination the most.

Concurrency isn't easy and implementing its primitives is even harder. I found myself in need of some no-std, no-alloc Rust async concurrency primitives and decided to write some. I kept the scope small so even you and I can understand it. Even so, it still involved futures, wakers, atomics, drop and unsafe. I'll introduce each of those to you while building a simple primitive. At the end, you will be able to implement your own primitives!

Recently, we worked on an embedded (STM32) project in Rust and we got some hands-on experience with the abstractions commonly used for that. There's embedded-hal, which offers abstractions related to timing, GPIO pins and common communication peripherals like SPI and USART. There's also multiple stm32xxx-hal crates which offer abstractions over most of the peripherals of different STM32 CPU families. Although many of them were nice to use, we found some parts to be lacking and we'd like to propose some potential improvements to embedded-hal and its implementing crates.

If one person at Tweede golf is a Rustacean, it’s definitely Wouter. Whether it’s about web, embedded, or even games: he tried it. And probably not just tried it, but prototyped, created, documented, presented, and nailed it. Just take a look at Wouter’s GitHub page[1]. He’s also engaged in the Rust community as an organizer of RustFest, member of the Dutch Rust foundation, and as maintainer of several open-source crates. He believes that Rust is well on its way to perfection.

Augustus 14, 2020

Functional Rust? (4/5)

Lars started at Tweede golf about a year ago. We lured him in with the prospect of working on a cool embedded project in Rust. Since then he clocked a lot of Rust hours on it and on a research project we are running. Still, he manages to astound us with critical notes on Rust. Rightly so? Let's just say interviewing a functional programming purist like Lars gives us a lot of new perspectives around Rust.

Marlon is the rookie at Tweede golf, joining us a few months back. He started out with Rust not too long ago and is therefore the guy to talk to about his learning experience with Rust.

Juli 31, 2020

Rust wide web (2/5)

Ruben has experience with a lot (and I mean a lot) of programming languages. When I asked which ones, he could name 21 off the top of his head. He loves experimenting with them, seeing what each can and can’t do. What makes a language unique? What can one language do better than the other? Why was Ruben the one to first evangelize Rust within Tweede golf? Let’s ask him!

The Dutch government offers the AHN [1] as a way to get information about the height of any specific place in the country. They offer this data by using a point cloud. That is, a large set of points with some additional meta information. With the current version of the AHN the resolution of the dataset is about eight points per square meter. This results in about 2.5TB of compressed data for the relatively small area of the Netherlands. While this is something that is not impossible to store locally, it does offer some challenges.

First-up is Henk Dieter, backend developer at Tweede golf. He has been interested in Rust for quite some time. Actually, it’s how Henk Dieter found out about Tweede golf, as it was one of the first companies in the Netherlands to adopt Rust as their weapon of choice.

In June 2020 Rust was voted Stack Overflow's Most Loved language for the 5th (!!!) year running. Stack Overflow is a leading resource for developers and its yearly developer survey the primary source for developers' preferences.

Typically embedded devices are developed using C++. At Tweede golf we have chosen to use Rust instead for implementing our embedded devices. This is controversial as the embedded hardware field is generally quite conservative. Convincing our clients to adopt Rust for their products can be a challenge.

Rust is nice for a lot of things. At Tweede golf we've been using the language primarily for high-performance web applications. But that's not all Rust can do. Rust can be used to write embedded applications as well.

Embedded software has an issue that most software doesn't: It can be very hard to get it patched. Sometimes a device hangs 5 meters high on a street light in the middle of a highway in another country. Sometimes a device is attached to a customer's heart. Sometimes strict validation requirements make changes to the software very expensive. In each case it is important to build software that doesn't fail, even in unpredictable conditions.

One of our clients helps companies in becoming GDPR-compliant. A goal is to recognize sensitive pieces of user data in a big pile of registrations, receipts, emails, and transcripts, and mark them to be checked out later. As more and more data is collected by companies, finding and eliminating sensitive data becomes harder and harder, to the point where it is no longer possible for mere human employees to keep up without assistance.

At Tweede golf, we’ve been visiting meetups and conferences throughout the years. As we have high hopes for Rust, and a strong personal adoration for the language, we decided on hosting our own Rust meetup and starting a Rust Nijmegen group.

We often get the question how productive working with Rust is. "We know that it is awesome, but isn't it hard to learn? Don’t you struggle with the borrow checker?". Well, we put it to the test in Google's Hash Code 2019 programming competition.

At Tweede golf I've been working with Rust a lot lately. My interest in Rust has been there for years, so I was very happy to start applying it in my working life, about a year ago. Since then I have worked with Rust both for our clients as well as employing it for our operations setup. I have also experimented with Rust for web \[1\]. Until now however we did not contribute to the Rust ecosystem. About time that we get our feet wet and publish our first crate!

September 3, 2018

Rust als webplatform?!

Wat is over 5 jaar het winnende open source webplatform? Inmiddels begint PHP - ondanks PHP7 - zijn ouderdom te tonen. Alternatieven als NodeJS zijn wel werkbaar, maar in lang niet alle scenario’s geschikt. We vertellen je graag waarom wij denken dat Rust de nieuwe speler kan worden voor high-performance applicaties op het web.