Software Development

826 Articles

Bare-Metal STM32: Setting Up And Using SPI

October 24, 2022 by 52 Comments

The Serial Peripheral Interface (SPI) interface was initially standardized by Motorola in 1979 for short-distance communication in embedded systems. In its most common four-wire configuration, full-duplex data transfer is possible on the two data (MOSI, MISO) lines with data rates well exceeding 10 Mb/s. This makes SPI suitable for high-bandwidth, full-duplex applications like SD storage cards and large resolution, high-refresh displays.

STM32 devices come with a variable number of SPI peripherals, two in the F042 at 18 Mb/s and five in the F411. Across the STM32 families, the SPI peripheral is relatively similar, with fairly minor differences in the register layout. In this article we’ll look at configuring an SPI peripheral in master mode.

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Arduino IDE v2.0 screen with callout tags to identify features

Arduino IDE 2.0 Is Here

September 28, 2022 by 84 Comments

Arduino have released the latest version of their Integrated Development Environment (IDE), Version 2.0 and it is a big step up from the previous release, boasting plenty of new features to help you to develop your code more easily.

As the de-facto way for beginners to get into programming hardware, more experienced users have sometimes complained about what they see as the over-simplistic IDE — even lacking relatively basic features such as autocomplete. The new version provides this, and much more besides. Continue reading “Arduino IDE 2.0 Is Here” →

A Spreadsheet For The Python Hacker

September 23, 2022 by 9 Comments

You can write a Python program or use a Jupyter Notebook to do almost anything. But you can also get a lot of things done quickly using a spreadsheet. Grist is a “hacker’s” spreadsheet that merges these worlds. It looks like a spreadsheet, but underneath are SQLite tables and the formula language is Python.

The code is open source and if you want it hosted, there are free and paid plans. You can even try it out without even logging in and either start with a blank screen or use a template. You can see an introductory video below.

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OpenAI Hears You Whisper

September 22, 2022 by 18 Comments

Should you wish to try high-quality voice recognition without buying something, good luck. Sure, you can borrow the speech recognition on your phone or coerce some virtual assistants on a Raspberry Pi to handle the processing for you, but those aren’t good for major work that you don’t want to be tied to some closed-source solution. OpenAI has introduced Whisper, which they claim is an open source neural net that “approaches human level robustness and accuracy on English speech recognition.” It appears to work on at least some other languages, too.

If you try the demonstrations, you’ll see that talking fast or with a lovely accent doesn’t seem to affect the results. The post mentions it was trained on 680,000 hours of supervised data. If you were to talk that much to an AI, it would take you 77 years without sleep!

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Fork And Run: The Definitive Guide To Getting Started With Multiprocessing

September 15, 2022 by 23 Comments

Since the early 2000s, the CPU industry has shifted from raw clock speed to core counts. Pat Gelsinger famously took the stage in 2002 and gave the talk the industry needed, stating processors needed specialty silicon or multiple cores to reduce power requirements and spread heat. A few years later, the Core series was introduced with two or four-core configurations to compete with the AMD Athlon 64 x2.

Nowadays, we’re seeing heterogeneous chip designs with big and little cores, chiplets, and other crazy fabrication techniques that are fundamentally the same concept: spread the thermal load across multiple pieces of silicon. This writer is willing to put good money into betting that you’ll see consumer desktop machines with 32 physical cores in less than five years. It might be hard to believe, but a 2013 Intel Haswell i7 came with just four cores compared to the twenty you’ll get in an i7 today. Even an ESP32 has two cores with support in FreeRTOS for pinning tasks to different cores. With so many cores, how to even write software for that? What’s the difference between processes and threads? How does this all work in straight vanilla C98?

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C23 Programming For Everyone

September 13, 2022 by 29 Comments

Here’s a history quiz: What architecture did the first C++ compiler target? Of course, it is a trick question. The original C++ — known then as C with classes — compiler wrote out standard C code that you then compiled for whatever your target was. This has a lot of advantages since C compilers are everywhere. Now we are seeing a similar approach to bring C23 to the world with Cake. Cake can translate C23 or other versions to C99 which you can then compile with normal compilers.

While the old C++ compiler, cfront, needed special steps to compile (since it was built using C++), you can build cake for Windows or Linux easily. However, it can also be built with emscripten and you can try it yourself in your web browser.

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The Big List Of Naughty Strings Helps Find Those User Input Problems

September 10, 2022 by 14 Comments

Any software that accepts user input must take some effort to sanitize incoming data, lest unexpected and unwelcome things happen. Here to make that easier is the Big List of Naughty Strings, an evolving list of edge cases, unusual characters, script-injection fragments, and all-around nonstandard stuff aimed at QA testers, developers, and the curious. It’s a big list that has grown over the years, and every piece of it is still (technically) just a string.

These strings have a high probability of surfacing any problems with handling user input. They won’t necessarily break anything, but they may cause unexpected things to happen and help point out any issues that need fixing. After all, many attacks hinge on being able to send unexpected inputs that don’t get properly sanitized.

Finding bad inputs is not always entirely straightforward, but at least the Big List of Naughty Strings is available in a variety of formats to make it easy to use. [Max Woolf] has been maintaining the list for years, but if you haven’t heard of it yet and think it might come in useful, now’s the time to give it a look. Now you can help ensure your system can handle things like someone registering a company named ; DROP TABLE “COMPANIES”;– LTD.