Five Embedded Linux Topics for Newbies !
Are you an embedded systems enthusiast looking to broaden your horizons with embedded Linux? explore those 5 topics.
Introduction to PIC Timers
The fourth in a series of five posts looks at 8-bit PIC hardware timers. After a review of basic timer functionality, the Timer0 module operation and configuration is reviewed and a basic application implemented using Timer0 to blink external LEDs at a frequency of 0.5Hz.
You Don't Need an RTOS (Part 2)
In this second article, we'll tweak the simple superloop in three critical ways that will improve it's worst-case response time (WCRT) to be nearly as good as a preemptive RTOS ("real-time operating system"). We'll do this by adding task priorities, interrupts, and finite state machines. Additionally, we'll discuss how to incorporate a sleep mode when there's no work to be done and I'll also share with you a different variation on the superloop that can help schedule even the toughest of task sets.
Finite State Machines (FSM) in Embedded Systems (Part 3) - Unuglify C++ FSM with DSL
Domain Specific Languages (DSL) are an effective way to avoid boilerplate or repetitive code. Using DSLs lets the programmer focus on the problem domain, rather than the mechanisms used to solve it. Here I show how to design and implement a DSL using the C++ preprocessor, using the FSM library, and the examples I presented in my previous articles.
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.
Linear Feedback Shift Registers for the Uninitiated
Jason Sachs assembled an eighteen-part deep dive into linear feedback shift registers, connecting the simple shift-register circuit to finite-field algebra and practical tools. The series walks through primitive polynomials, Berlekamp-Massey state recovery, libgf2-based analysis, discrete-log methods, and real-world uses from PRNGs and Gold codes to Reed-Solomon and CRC reverse-engineering. It’s a single reference for engineers who want both theory and working code.
2024 Embedded Online Conference's Schedule
Packed with live workshops, keynotes, and dozens of on-demand talks, the 2024 Embedded Online Conference hands you a full week of embedded-systems learning. Most theatre talks and microtalks drop early on April 26 to let you binge ahead, while major workshops and keynotes run live on Zoom with multiple 20-minute Q&A sessions. Use the schedule to add sessions to your agenda and expect occasional last-minute changes.
A design non-methodology
Although writing an RTOS or kernel may be an interesting project, it is unlikely to be a wise course of action.
Working with Microchip PIC 8-bit GPIO
The third in a series of five posts looks at GPIO with PIC 8-bit microcontrollers. After a detailed review of the registers for configuring and managing GPIO on the PIC18F47Q10 processor, a basic application is stood up programming those registers to blink external LEDs at 0.5Hz.
How to use I2C devices in (Apache) NuttX: Scanning for Devices
Hands-on guide to scanning I2C peripherals on NuttX using a Raspberry Pi Pico, showing how the RTOS exposes i2c master instances and the i2ctool. The article walks through where the RP2040 I2C driver lives, how to enable I2C0 in menuconfig, build and flash nuttx, and run the i2c dev command to probe the bus. Verify sensors like BMP280 or SSD1306 before registering drivers.
Getting Started With Zephyr: West Manifest Customization
Create a reproducible Zephyr development baseline by customizing a West manifest, so your team avoids surprises from upstream changes. This post walks through forking Zephyr and MCUBoot when you need local changes, adapting Nordic Semiconductor's west.yml as a template, and updating remotes and defaults to point at your forks. Finish by running west init -m
Introduction to Microcontrollers - 7-segment displays & Multiplexing
Seven-segment displays can eat dozens of GPIO pins and dozens of resistors, but multiplexing trades pins for time and cuts component count dramatically. Mike Silva shows a hands-on AVR C implementation with segment encoding, a 100 Hz display scan ISR, several integer-to-digit conversion techniques, and software workarounds for messy pin mappings. He also demonstrates a timer "leapfrog" to reuse one timer for two tasks and compares performance so you can choose the best approach for your MCU.
How to Achieve Deterministic Behavior in Real-Time Embedded Systems
Ensuring deterministic behavior in real-time embedded systems is paramount for their reliability and performance. The ability to predict precisely how a system will respond to various inputs at any given time is crucial in critical applications such as medical devices, aerospace systems, and automotive safety mechanisms. Achieving deterministic behavior involves meticulous design, stringent testing, and adherence to strict timing constraints.
Lost Secrets of the H-Bridge, Part II: Ripple Current in the DC Link Capacitor
DC link capacitor ripple often determines capacitor life, yet the H-bridge waveform has a lot more structure than you might expect. Jason Sachs separates capacitor current into ramp and pulse components, derives closed-form peak and RMS expressions for edge and center PWM, and shows harmonic amplitudes. The post includes Python simulation so you can visualize the waveforms and apply the formulas to capacitor selection and EMI analysis.
7 Essential Steps for Reducing Power Consumption in Embedded Devices
Reducing the amount of power your embedded device is consuming is not trivial. With so many devices moving to battery operations today, maximizing battery life can be the difference between a happy, raving customer and an unhappy one that ruins your company's reputation. This post explores seven steps for optimizing your embedded systems' power consumption. You'll gain insights into the steps and techniques necessary along with receiving a few resources to help you on your journey.
Second-Order Systems, Part I: Boing!!
Jason Sachs takes the spring 'boing' of a doorstop into the math of second-order systems, using the series LRC circuit as a concrete example. He shows two standard transfer-function forms, explains why ωn only scales time while ζ sets the response shape, and derives pole locations plus an exact overshoot formula that helps tune embedded-system responses.
Arduino robotics #3 - wiring, coding and a test run
Lonnie Honeycutt walks through wiring, coding, and the first test run of Clusterbot, a budget Arduino robot build costing about $50. The post provides a clear pin-mapping to the TB6612FNG motor driver, ready-to-upload Arduino movement functions, and practical tips like tinning thin battery wires. You also get PWM calibration values and the measured RPM timing the author used to make reliable turns.
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.
Favorite Software AND Hardware Tools for Embedded Systems Development
Tool choice can make or break an embedded project, and Stephane Boucher gathered developers' favorite hardware and software picks from the Embedded Online Conference into one handy roundup. The post points to a companion video and lists concrete tools from oscilloscopes and logic analyzers to J-Link probes, Python, unit-test frameworks, and soldering irons. It is a quick, practical peek at what experienced embedded engineers actually use.
What to See at Embedded World 2019
Skip the overwhelm at Embedded World 2019, Stephane Boucher lays out a practical preview of what to see and how to prioritize your time. The post helps embedded engineers focus on demos, vendor booths, and sessions that matter without getting lost on the show floor. Read it to plan a short, efficient visit that maximizes technical takeaways and networking opportunities.
Linear Feedback Shift Registers for the Uninitiated, Part XVI: Reed-Solomon Error Correction
Jason Sachs demystifies Reed-Solomon codes with hands-on examples and pragmatic tips for embedded engineers. The article shows why RS encoding is just polynomial division in GF(2^m), why decoding is mathematically heavier, and how to implement encoders in Python and in C-friendly form using LFSRs and table-driven methods. Read this for working code, generator-polynomial examples, and an embedded-minded view of RS practicalities.
Lost Secrets of the H-Bridge, Part III: Practical Issues of Inductor and Capacitor Ripple Current
Jason Sachs cuts through the math to show what ripple current actually does to H-bridge hardware. He explains why peak current is the limiting factor for inductors, why capacitor ESR usually dominates DC-link voltage ripple, and how center-aligned PWM and duty selection reduce harmonics and ripple. Read this if you want practical rules of thumb and calculation templates for real power-electronics designs.
Important Programming Concepts (Even on Embedded Systems) Part IV: Singletons
Singletons are convenient but often a modularity killer, especially in embedded firmware. Jason Sachs walks through the many faces of singletons, from static members and globals to hardware registers and user-visible application singletons, and shows practical ways to avoid tight coupling. Read this for concrete embedded examples and pragmatic fixes like passing state explicitly, using interfaces or factories, and isolating unavoidable globals in a HAL.
Free Goodies from Embedded World - What to Do Next?
Stephane Boucher went on a hunt for free stuff at Embedded World to assemble a giveaway bundle for a lucky reader. This short update shares that haul and asks the embedded community for ideas on what to do next. It is a conversational call for suggestions, aiming to turn conference swag into a useful prize.
Embedded Toolbox: Programmer's Calculator
A tiny but powerful cross-platform tool, QCalc evaluates full C-syntax expressions so you can paste results straight into firmware. It handles bitwise ops, mixed hex/decimal/binary constants, and scientific math, and it automatically shows integer results in formatted hex and binary. The post explains key features, variable handling, error messages, and how to run qcalc.tcl with the wish Tk interpreter.
A New Related Site!
The post announces the launch of MLRelated, a new Related site dedicated to machine learning and deep learning. It positions MLRelated as complementary to existing Related sites by highlighting cross-cutting interests: TinyML for embedded developers, machine/deep learning applications in signal processing, and FPGA-based AI/ML implementations. The new site debuts with a modest amount of content and is expected to expand rapidly through contributions from the Related community in the form of blogs, forum threads, and webinars. The author invites readers to report navigation errors, share feedback, and propose ideas to help steer MLRelated into a practical, community-driven resource for researchers and practitioners in ML and adjacent domains.
Delayed printf for real-time logging
Yossi Kreinin demonstrates delayed printf, a technique that records printf format pointers and raw argument words into a compact buffer so logging does not disturb real-time timing. He walks through a small C++11 writer using variadic templates and an atomic buffer plus a gdb Python reader that reconstructs formatted messages from executables or core dumps. The result is readable post-processed logs with minimal runtime overhead.
The Least Interesting Circuit in the World
Jason Sachs pulls apart the humble power-on reset and shows why the common RC-and-Schmitt trick is the least interesting but most dangerous circuit in your design. He walks through voltage thresholds, brown-out reset behavior, and how slow or noisy Vdd ramps can let parts start in indeterminate states. Read this for practical rules on choosing supervisors, comparators, and reset pulse timing to ensure reliable embedded startup.
Two Capacitors Are Better Than One
Jason Sachs revisits a simple stacked RC trick that dramatically reduces DC error from capacitor insulation leakage in long time-constant filters. Splitting one RC into two stages forces most of the DC drop onto the lower capacitor, squaring the remaining error while changing the effective pole locations. The post walks through the math, practical component tradeoffs, and when to prefer a digital approach.
Introduction to Microcontrollers - More On Interrupts
Interrupts are powerful but dangerous, and Mike Silva breaks down how they actually behave on microcontrollers and why they can corrupt data. This post explains latched flags, pending and priority behavior, ISR nesting, and common read-modify-write hazards, then shows practical fixes like targeted interrupt masking and using atomic GPIO hardware so you can stop chasing sporadic bugs.
