Here are the articles, videos, and tools that we’ve been excited about this January.

We hope you enjoy these links, and we look forward to hearing what you’ve been reading in the comments or on the Interrupt Slack.

Articles & Learning

• The most thoroughly commented linker script (probably) by Stargirl
  Title says it all.
• Ending the Embedded Software Dark Ages: Let’s Start With Processor Fault Debugging! by Phillip Johnston at Embedded Artistry
  Phillip dives deep into the fault handling routines of the ARM Cortex-M and investigates how a developer can go beyond manual debugging by using coredumps (so exciting!).
• A 27th IOCCC Winner - Best of show - abuse of libc by Nicholas Carlini
  TIL that printf is Turing complete. In this IOCCC entry, the author implements Tic-Tac-Toe in a single printf statement!
• Better Embedded System Software e-Book & Paperback by Phil Koopman
  Phil has updated his popular embedded systems book with what he calls a v1.1 edition. The hardcover was prohibitivly expensive for some (but worth it), and this new version comes in both a paperback book and digital version, costing $25 and $10 respectively, which is a steal. The group in the Interrupt Slack channel say it’s a worthwhile purchase for hte new price.
• Thoroughly Commented Cortex M0+ Micro Trace Buffer interface (Twitter) by Stargirl
  The Micro Trace Buffer on the Cortex-M0+ (and the ETB) are some notoriously difficult modules to get set up, and they are rarely included by chip vendors in a package. A few of Stargirl’s hardware products under the brand Winterbloom use the SAMD21, which does include the MTB! In the Tweet above, she links to the MTB initialization code in the firmware.
• Linux and Zephyr, Sitting in a tree (slides) by Christopher Biggs
  Tips, tricks, and lessons learned from using Zephyr on a Raspberry Pi. Christopher covers why someone would want to use an RTOS instead of Embedded Linux, how to get things building and flashing, and gives some final tips based on a real-world project.
• VSCode, Dev Containers and Docker: moving software development forward by Niall Cooling
  Niall covers how to get started unit testing with Ceedling, GoogleTest, and VScode using VSCode’s built-in Docker container integration. Be sure to check out his following post on Github Workspaces.
• Schematic Design Review Checklist by Stratify Labs
  You can tell this article (and the PCB Layout Checklist) are both written from true experience. Check these out if you are in the process of designing or building your own boards, whether they are mounted on Legos or not.
• Unit Testing with PlatformIO: Part 1. The Basics by Valerii Koval
  A thorough walkthrough of how to use the built-in Unity unit testing functionality with PlatformIO and its VSCode plugin.

Neat Projects

• Winterbloom - Castor & Pollux Firmware
  As mentioned above, this is the Github repo for a Winterbloom oscillator, complete with everything you could ask for! Factory scripts, hardware and software code, and documentation. A very good resource for someone wanting to look at an open-source Cortex-M0+ based firmware.
• SPIFFS (SPI Flash File System)
  A file system built for SPI NOR flash devices. It might be a good alternative to LittleFS.
• bytefield-svg
  An SVG library to help build byte-field diagrams, such as those showing network protocols and memory layouts. A similar package to WaveDrom.
• PCB Brick Mount by Kerry Scharfglass
  Ever thought layout out multiple PCB’s together was a pain? James Munns did too, and he came up with a Lego-like system to mount PCB’s onto. Check out his Github repo which contains KiCAD footprints and the various boards James has designed himself.
• Siliconpr0n
  A collection of die images of a plethora of chips.
• aosp-riscv
  Android running on RiscV!? Neat.
• Watchy Pebble-like Smartwatch with E-paper display, ESP32 processor launched on Crowd Supply
  Watchy, an ESP32-based E-paper smartwatch board that is being sold on CrowdSupply. I love this because it means that I might finally get to wear something Pebble-like on my wrist again!

News

• Raspberry Pi Pico
  A fascinating new announcement from the group behind the Raspberry Pi, the Pico! The RP2040 features a dual-core ARM Cortex-M0+, 264kB of RAM, and 16MB of flash. Did I mention it’s $4 and it runs MicroPython? Sign me up. I imagine this will be a very popular prototyping board for new hardware projects.
• NXP published MCUXpresso SDK 2.9.0 on GitHub by Erich Styger
  NXP has realized that providing .zip files of their SDK is outdated and cumbersome to use. Yay! They’ve also published it under a permissible license, BSD-3. Double yay! I wish all vendors take notes.
• EdgeLock 2GO - Secure, flexible IoT service platform
  NXP announced their IoT platform, EdgeLock 2GO. I’d love to know who’s using this. (Do reach out if you are, I’m very curious.)
• This Bluetooth Attack Can Steal a Tesla Model X in Minutes by Andy Greenberg
  It wouldn’t be an Interrupt blogroll post without a new Tesla hack over Wi-Fi or Bluetooth.