Learning From Engineering Failures
Engineering failures are the best teachers when you study them with curiosity and rigor. This post gathers the author's approach and curated resources for learning from incidents, with an emphasis on treating human error as a symptom of layered systemic problems rather than the root cause. Read on for practical guidance, longtime sources like Risks Digest, and a mindset: trust nothing, and verify.
Acceptance Tests vs. TDD
Writing the tests in a Jira ticket is not the same as doing TDD, this post explains why. It separates acceptance tests, which define business completeness and are written up-front by the customer, from TDD unit tests, which developers write incrementally as a design and feedback tool. Readable advice covers test speed, avoiding brittle tests, and how both test types fit into CI and maintainable embedded development.
Embedded Online Conference 2021 - Watch the Speakers Share their Thoughts on the Value for Attendees
Stephane Boucher gathered short interviews with several speakers from the upcoming Embedded Online Conference, asking them why conferences matter and what makes this event worth attending. Their answers are edited into a single video that highlights practical reasons to tune in. If you haven't registered yet, use promo code ER149 to save more than 40% on your registration fee.
8 Weeks - 8 Giveaways!
Eight weeks, eight hardware and training prizes aimed at embedded engineers, from oscilloscopes to Tracealyzer licenses. Register for the 2021 Embedded Online Conference before each week's raffle date and you'll be automatically entered to win items like a Rigol scope, Saleae Logic Pro 8, Joulescope, RTOS workshops, and more. Use promo code ER90 to save $100 on registration through April. Practical prizes to boost your bench and skills.
My Guiding Principles As An Engineer
An embedded-systems veteran distills 40 years of experience into practical guiding principles for engineers. The post mixes classic quotes with hard-earned aphorisms focused on testing, instrumentation, planning, and integrity, showing how persistence, preparation, and evidence-based thinking prevent mistakes. Read it for concise, actionable habits you can apply to firmware, hardware-software integration, and team practices.
Dumb Embedded System Mistakes: Running The Wrong Code
Running the wrong firmware on a board can waste hours. This post shows a practical marking strategy for embedded Linux that embeds searchable proof-of-life strings into kernel, rootfs, overlay, and application code. It walks through choosing early-boot log points, using compile-time timestamps, and a small shell script to set, find, and clear marks so you can verify builds before flashing.
Announcing the 2021 Embedded Online Conference!
Big names, hands-on workshops, and a generous promo code make the 2021 Embedded Online Conference worth registering for. Stephane Boucher and Jacob Beningo announced Jack Ganssle will deliver the keynote on the 50th anniversary of the microprocessor, with TDD and RTOS workshops taught by James Grenning and Jacob Beningo. Register this week to get access to 2020 on-demand talks and use promo code ER90 to save more than 50% on registration.
Advice For High School Students
Short attention span engineering is a recipe for disaster, so this post gives practical, no-nonsense advice to high school students thinking about engineering majors. It explains how to build college-ready study habits, why hands-on projects like Arduino or Raspberry Pi matter, which math you should focus on, and which soft skills will make you a reliable engineer.
Your Career Archive
Background checks have turned routine hiring into a paperwork sprint, and many engineers find themselves scrambling for proof. This post shows how to build a practical career archive of job records, education documents, and tax/payroll forms, plus advice on redaction, storage formats, and backups. Capture verifiable details when you get them to avoid last-minute stress and make future vetting simple and reliable.
Painting with Light to Measure Time
When Jason Sachs needed to verify a first-order sigma-delta LED dimming implementation but had no oscilloscope, he turned to long-exposure "light painting" to turn time into space on a photograph. By sweeping the camera across blinking LEDs he captured pulse trains, read the bit patterns from the light trail, and confirmed the result with a tiny Python accumulator model. The post shares practical tips on timing accuracy, exposure, and avoiding ambient-light artifacts.
How to Estimate Encoder Velocity Without Making Stupid Mistakes: Part I
Encoder velocity estimation is easy to get wrong, and Jason Sachs walks through the traps engineers fall into. He demolishes the common advice to time between encoder edges, shows how encoder quantization and state-width errors break that approach, and argues for fixed-rate sampling with sensible filtering for most control uses. Part II will cover more advanced estimators for higher performance needs.
Getting Started With Zephyr: Bluetooth Low Energy
In this blog post, I show how to enable BLE support in a Zephyr application. First, I show the necessary configuration options in Kconfig. Then, I show how to use the Zephyr functions and macros to create a custom service and characteristic for a contrived application.
Turn It On Again: Modeling Power MOSFET Turn-On Dependence on Source Inductance
This is a short article explaining how to analyze part of the behavior of a power MOSFET during turn-on, and how it is influenced by the parasitic inductance at the source terminal. The brief qualitative reason that source inductance is undesirable is that it uses up voltage when current starts increasing during turn-on (remember, V = L dI/dt), voltage that would otherwise be available to turn the transistor on faster. But I want to show a quantitative approximation to understand the impact of additional source inductance, and I want to compare it to the effects of extra inductance at the gate or drain.
Elliptic Curve Cryptography - Extension Fields
An introduction to the pairing of points on elliptic curves. Point pairing normally requires curves over an extension field because the structure of an elliptic curve has two independent sets of points if it is large enough. The rules of pairings are described in a general way to show they can be useful for verification purposes.
ANCS and HID: Controlling Your iPhone From Zephyr
In this blog post, we see how certain BLE services can be used to control an iPhone from a Nordic nRF52840 using The Zephyr Project. Specifically, we see how to control certain multimedia functionality using the HID service. Finally, we learn how to use the ANCS client library provided by Nordic in The Zephyr Project to accept or decline an incoming call.
Voltage - A Close Look
The post examines what voltage actually indicates in fast circuits by revisiting a classic interview puzzle and transmission-line wave behavior. Using a voltmeter and a compass to infer electric and magnetic field directions, the author shows how the right-hand rule reveals energy-flow direction rather than a simple ‘voltage source’ location. Revisiting leading and reflected waves on an open transmission line, the post explains that reflected wave fronts convert magnetic field energy into electric field energy (doubling the voltage at the open) and that energy is exchanged between field forms rather than being lost or simply ‘reflected away.’ The author emphasizes that voltage can represent storage, flow, or dissipation depending on context, and that an oscilloscope remains the primary practical tool for observing these energy phenomena in high-speed design.
EOC 2024 - I Will Attend Giveaways!
Win serious test gear by helping spread the word about the Embedded Online Conference, invites Stephane. Share the provided image on LinkedIn with #EOC2024 and #embeddedsystems by April 29 to enter raffles for gear like a LulzBot Mini 2, Saleae Logic Pro 8, Joulescope JS220, and a DSC-5300 oscilloscope. It only takes a few minutes to qualify.
Basic hand tools for electronics assembly
Though the software tools vary with different microcontrollers, many hardware tools are the same.
When a Mongoose met a MicroPython, part I
This is more a framework than an actual application, with it you can integrate MicroPython and Cesanta's Mongoose.
Mongoose runs when called by MicroPython and is able to run Python functions as callbacks for the events you decide in your event handler. The code is completely written in C, except for the example Python callback functions, of course. To try it, you can just build this example on a Linux machine, and, with just a small tweak, you can also run it on any ESP32 board.
PC and SP for a small CPU
Victor Yurkovsky walks through a compact stack-based CPU idea that tosses the conventional PC register in favor of a return stack living in Xilinx distributed RAM. The clever twist uses the stack memory addressed by SP as the program counter, making calls trivial and keeping the design tiny. The article shows the Verilog stack module and explains the practical tradeoffs of isolating the return stack.
Ada 2012 Comes to ARM Cortex M3/M4
Ada is not dead, and Mike Silva shows why by walking through Ada 2012 running on ARM Cortex‑M3/M4 hardware. He demos an STM32F4 LED-and-button example that highlights Ada advantages: strong typing, modular types, built-in time and tasking, and protected objects for safe concurrency without an RTOS. The post also notes AdaCore's GNAT tooling and links to further resources to get started.
Back from ESC Boston
Stephane nearly skipped ESC Boston, but going turned into a productive mix of networking, informal meetups, and on-the-floor filming. He captures candid encounters with speakers and vendors, learns how small shows differ from larger expos, and outlines practical follow-ups like booth highlight videos and speaker hospitality suggestions. The post is an encouraging read for engineers weighing the value of regional conferences and DIY event coverage.
Embedded World 2018 - More Videos!
Two cinematic videos from Embedded World 2018 turn the show floor into slow-motion, stabilized footage using a Zhiyun Crane gimbal and a Sony a6300. One is a SEGGER booth highlights piece featuring Rolf Segger and Axel Wolf, the other is a roaming montage with appearances from Jacob Beningo, Micheal Barr, and Alan Hawse. Stephane asks viewers to enable audio and share feedback.
Watchdog Timer Anti-patterns
A watchdog timer can be useless or even harmful when misused. This post catalogs the most common watchdog anti-patterns, including feeding the watchdog unconditionally from a timer ISR, suspending it during long operations, sprinkling resets across code, timeout auctions, incomplete reset trees, and treating process supervision as a substitute for hardware. It finishes with practical rules to design watchdogs that genuinely improve embedded system reliability.
Embedded World 2018 - The Interviews
Stephane Boucher brought video gear to Embedded World 2018 and teamed up with Jacob Beningo to capture concise vendor interviews that focus on real product news. The videos showcase Percepio's new Tracealyzer with a drone demo, Intrinsic ID's method for creating device-unique IDs from manufacturing variations, and SEGGER's broader toolset including embOS now certified by TÜV SÜD. Watch for short demos and expert explanations.
Modeling Gate Drive Diodes
This is a short article about how to analyze the diode in some gate drive circuits when figuring out turn-off characteristics --- specifically, determining the relationship between gate drive current and gate voltage during turn-off of a power transistor.
Margin Call: Fermi Problems, Highway Horrors, Black Swans, and Why You Should Worry About When You Should Worry
Jason Sachs walks through practical strategies for choosing engineering margin, from split-second Fermi estimates to industry-grade safety factors. He blends highway and boiler anecdotes with a MOSFET thermal example to show why probabilistic thinking, experiments, and documentation matter when you must decide fast or later justify your choices. Read this to learn how to balance conservatism, cost, and risk in real projects.
Use Microprogramming to Save Resources and Increase Functionality
Microprogramming can rescue an overfull FPGA, Michael Morris shows, by compressing control logic and time-multiplexing FIFO storage. He replaces an ABEL state machine with a small microprogram ROM that uses block RAM for deep Rx/Tx FIFOs and LUT RAM for pointers and counters, freeing about 25 percent of the device. The article includes Verilog comparisons, resource tables, and a microassembler link to reproduce the approach.
SEGGER's 25th Anniversary Video
Stephane Boucher spent a week at SEGGER's headquarters and distilled that visit into a tight, two-minute 25th anniversary video. The post highlights rising production value, thanks to softbox lighting and a two-camera setup that allows seamless wide-to-tight cuts and emotional close-ups. Stephane invites readers to watch full screen, leave feedback and thumbs-up on YouTube, and suggests future coverage like product launches or companies with happy engineers.
Supply Chain Games: What Have We Learned From the Great Semiconductor Shortage of 2021? (Part 4)
The chip shortage didn't end with 2021, it moved into older process nodes where cars and industrial gear live. In this installment Jason Sachs explains why mature-node and trailing-edge capacity remain tightly constrained, how NCNR commitments and price increases are reshaping supplier behavior, and what companies like NXP and Microchip are doing to cope. He warns the imbalance could take multiple semiconductor cycles to fix.
