Creating a GPIO HAL and Driver in C
Creating a GPIO Hardware Abstraction Layer (HAL) in C allows for flexible microcontroller interfacing, overcoming the challenge of variability across silicon vendors. This method involves reviewing datasheets, identifying features, designing interfaces, and iterative development, as detailed in the "Reusable Firmware" process. A simplified approach prioritizes essential functions like initialization and read/write operations, showcased through a minimal interface example. The post also highlights the use of AI to expedite HAL generation. A detailed GPIO HAL version is provided, featuring extended capabilities and facilitating driver connection through direct assignments or wrappers. The significance of a configuration table for adaptable peripheral setup is emphasized. Ultimately, the blog illustrates the ease and scalability of developing a GPIO HAL and driver in C, promoting hardware-independent and extensible code for various interfaces, such as SPI, I2C, PWM, and timers, underscoring the abstraction benefits.
Using (Apache) NuttX USERLED Subsystem
Controlling an LED with raw GPIO works, but NuttX's USERLED subsystem makes it cleaner and portable. This post walks through enabling the LED driver in menuconfig, mapping the RaspberryPi Pico LED in the board files, and using the /dev/userleds device with printf to set up to 32 LEDs with a single write. It finishes with a hands-on challenge to expand the setup to eight LEDs on a breadboard.
3D printing for embedded development
Used mostly for creating little plastic objects, the desktop 3D printer is not an obvious addition to the embedded developer's toolbox. However, if you're looking for more reasons to get one, or already have one that's mostly gathering dust, here are a couple of embedded-related ways to get more value out of it.
Unraveling the Enigma: Object Detection in the World of Pixels
Exploring the realm of embedded systems co-design for object recognition, this blog navigates the convergence of hardware and software in revolutionizing industries. Delving into real-time image analysis and environmental sensing, the discussion highlights advanced object detection and image segmentation techniques. With insights into Convolutional Neural Networks (CNNs) decoding pixel data and autonomously extracting features, the blog emphasizes their pivotal role in modern computer vision. Practical examples, including digit classification using TensorFlow and Keras on the MNIST dataset, underscore the power of CNNs. Through industry insights and visualization aids, the blog unveils a tapestry of innovation, charting a course towards seamless interaction between intelligent embedded systems and the world.
Finite State Machines (FSM) in Embedded Systems (Part 1) - There's a State in This Machine!
An introduction to state machines and their implementation. Working from an intuitive definition of the state machine concept, we will start with a straightforward implementation then we evolve it into a more robust and engineered solution.
How Embedded Linux is used in Spacecrafts !
This article dives into the application of Linux in spacecraft, examining the challenges it poses and proposing potential solutions. Real-life examples will be discussed, while also addressing the drawbacks of employing Linux in safety-critical missions.
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.
++i and i++ : what’s the difference?
Although the ++ and -- operators are well known, there are facets of their operation and implementation that are less familiar to many developers.
Using GPIO in (Apache) NuttX RTOS
Blinking an LED is the embedded Hello World, and this tutorial walks through using GPIOs on NuttX running on a Raspberry Pi Pico. It shows how to enable the GPIO driver and example in menuconfig, build and flash the nuttx.uf2, and use NSH gpio device files to read and write pins. The post also explains polling versus interrupt-driven inputs and the pull-up/edge setup needed for button interrupts.
Mastering Modern FPGA Skills for Engineers
In the rapidly evolving tech industry, engineers must acquire proficiency in modern FPGA skills. These skills empower engineers to optimize designs, minimize resource usage, and efficiently address FPGA design challenges while ensuring functionality, security, and compliance.
Scorchers, Part 3: Bare-Metal Concurrency With Double-Buffering and the Revolving Fireplace
Jason Sachs presents a practical, low-overhead concurrency pattern for tiny bare-metal systems where an ISR (Speedy) must safely exchange data with a nonreal-time main loop (Poky). He describes the "revolving fireplace", a double-buffering variant that swaps ownership of two shared memory regions, and walks through C examples, atomic/volatile considerations, and testing strategies so you can implement it on RAM-constrained MCUs.
Introduction to Microcontrollers - More On GPIO
Polarity matters: an output '1' does not always mean an LED lights, and inputs are just as picky. This post walks through LED driving basics, pull resistors for buttons, and practical bitwise techniques to read and write individual GPIO pins on AVR and STM32 boards. It also explains why polling rates and mechanical bounce make button handling trickier than it looks and what to watch for next.
Unit Tests for Embedded Code
Unit tests are one of the most effective ways to catch logic bugs early and protect embedded firmware against regressions. Stephen Friederichs explains why unit testing matters for microcontroller code, when to test, and the trade-offs between on-target and hosted approaches, with practical advice on stubbing, using the Check framework, simulators, and coverage tools to make testing realistic for embedded projects.
Review: Hands-On RTOS with Microcontrollers
Brian Amos's Hands-On RTOS with Microcontrollers delivers a practical path from bare-metal to full RTOS applications using FreeRTOS on an STM32 Nucleo-F767ZI board. The book combines clear explanations of concurrency, interrupts, and DMA with step-by-step toolchain setup and runnable examples that show building, debugging, monitoring, and scaling embedded systems for real projects and coursework.
Getting Started with NuttX RTOS on Three Low Cost Boards
You can get Linux-like power on cheap microcontroller boards using NuttX, not a full Linux system. This article walks through building and flashing NuttX on three low-cost targets: Raspberry Pi Pico (RP2040), ESP32-DevKitC, and STM32F4Discovery, covering SDKs, toolchains, and serial access. Follow the provided commands to configure, compile, and connect to the NuttShell so you can start experimenting with NuttX quickly.
How to Analyze a Three-Op-Amp Instrumentation Amplifier
The three-op-amp instrumentation amplifier gives you high input impedance, improved net bandwidth, and much lower sensitivity to resistor mismatch than a single-op-amp differential stage. Jason M. Sachs walks through the algebra, numeric examples, and historical notes to show how the preamp isolates common-mode, why splitting gain boosts bandwidth, how overall gain can be set with one resistor, and what practical limits to watch.
Project Directory Organization
A tidy project tree can make a bigger difference than you might think. Stephen Friederichs lays out a practical directory scheme for small software projects, using familiar folders like src, obj, bin, test, reports, docs, and conf to keep builds, tests, and documentation from turning into a mess. He also explains why the root directory should welcome contributors, not confuse them.
Jumping from MCUs to FPGAs - 5 things you need to know
Are you a microcontroller expert beckoned by the siren song of the FPGA? Not long ago, that was me. FPGA-expert friends of mine regularly extolled the virtues of these mysterious components and I wanted in. When I made the leap, I found a world seemingly very familiar, but in reality, vastly different. I found that my years of C programming and microcontroller use often gave pre preconceived interpretations of FPGA resource material which resulted in eye-roll class mistakes in my code. I’ve gleaned five things of vital importance to help you make that transition faster than I did.
How to Deploy Local LLMs for Embedded Software Development: The Inference Stack and Honest Comparison
Achieving data sovereignty and offline reliability in embedded software development requires a robust, self-hosted LLM inference stack. Beyond the hype of massive parameter counts, performance depends on how models handle specialized architectural abstractions. Discover how to build a high-fidelity evaluation pipeline using Claude Code, LiteLLM, and vLLM to benchmark local models against frontier equivalents. By mapping real-world Zephyr project requirements to hardware, you can cut through the noise and identify which models actually deliver code that compiles, ensuring your development workflow remains secure, predictable, and exceptionally efficient.
From bare-metal to RTOS: 5 Reasons to use an RTOS
Most developers default to bare-metal, but Jacob Beningo argues an RTOS often simplifies modern embedded design. He outlines five practical reasons to move to an RTOS: easier integration of connectivity stacks and GUIs, true preemptive scheduling with priorities, tunable footprints, API-driven portability, and a common toolset for tasks and synchronization. The piece helps decide when RTOS adoption speeds development.
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.
Ten Little Algorithms, Part 4: Topological Sort
Jason Sachs detours from signal processing to make topological sort feel practical and even a little funny, using a Martian Stew recipe to illustrate dependencies and cycles. He walks through two canonical algorithms, Kahn’s method and the depth-first-search variant, compares adjacency-list and matrix graph representations, and provides complete Python implementations so you can run and inspect cycle detection and ordering yourself.
Android for Embedded Devices - 5 Reasons why Android is used in Embedded Devices
Android may seem like a phone OS, but it now solves real embedded product problems. This post outlines five practical reasons engineers pick Android for devices with displays, from built-in touch and GUI frameworks to simplified camera and wireless APIs. It also covers vendor BSP and driver support, a large developer pool, and how Android speeds prototyping by reusing phones or tablets as HMIs or processors.
Memory Mapped I/O in C
Interacting with memory mapped device registers is at the base of all embedded development. Let's explore what tools the C language - standard of the industry - provide the developer with to face this task.
Simulating Your Embedded Project on Your Computer (Part 1)
Having a simulation of your embedded project is like having a superpower that improves the quality and pace of your development ten times over! To be useful, though, it can't take longer to develop the simulation than it takes to develop the application code and for many simulation techniques "the juice isn't worth the squeeze"! In this two-part blog series, I'll share with you the arguments in favor of simulation (so, hopefully, you too believe in its value) and I'll show you what works (and what doesn't work) to help you to simply, easily, and quickly simulate your embedded project on your computer.
Review: Embedded Software Design: A Practical Approach to Architecture, Processes, and Coding Techniques
Jacob Beningo's Embedded Software Design is a practical, discipline-first guide to building reliable embedded systems. It frames development around a software triad: architecture, Agile/DevOps processes, and coding techniques, with security integrated from the start. The book mixes principles with hands-on recipes and includes appendices that walk through GitLab CI/CD and TDD examples you can reuse on real projects.
Someday We’ll Find It, The Kelvin Connection
Low-ohm measurements will fool your multimeter unless you use Kelvin connections. Jason Sachs walks through four-wire sensing using a current-limited supply and two DMMs, explains thermoelectric and connector-related errors, and shows why schematics and PCB layout must reflect Kelvin sense pads to avoid subtle measurement and circuit problems.
C Programming Techniques: Function Call Inlining
Fabien Le Mentec shows how you can keep clean C interfaces while recovering the cycles lost to function call overhead. The post demonstrates static inline and header inclusion techniques, then compares generated ARM assembly for an inlined versus non inlined bit test. Read it to see concrete assembly differences, compiler hints, and the practical trade off between speed and code size on embedded targets.
Another 10 Circuit Components You Should Know
Jason Sachs walks through ten underrated circuit components every embedded engineer should know, from bus switches and thermocouple signal ICs to PCB stiffeners and opto-FET isolators. He mixes practical part examples, high-current hardware tips, and MCU features like CTMU and Peripheral Pin Select so you can pick the right trick when space, isolation, or precision matter.
