How to Estimate Encoder Velocity Without Making Stupid Mistakes: Part II (Tracking Loops and PLLs)
Jason Sachs explains why simple differentiation of encoder counts often fails and how tracking loops and PLLs give more robust velocity estimates. Using a pendulum thought experiment and Python examples, he shows how a PI-based tracking loop reduces noise and eliminates steady-state ramp error, and why vector PLLs with quadrature mixing avoid cycle slips and atan2 unwrap pitfalls in noisy or analog sensing.
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.
Short Takes (EE Shanty): What shall we do with a zero-ohm resistor?
When you need flexibility on a PCB, zero-ohm resistors are the obvious shortcut, but Jason M. Sachs shows why the label zero is misleading. He compares common SMT jumper specs, high-current specialty parts, and a practical workaround using 1 milliohm resistors to avoid voltage drop. Read this for a quick checklist to pick jumpers that actually carry your board's current.
BGA and QFP at Home 1 - A Practical Guide.
It's a myth that BGAs and fine-pitch QFPs can't be soldered at home. Victor Yurkovsky lays out a practical, no-frills approach for hobbyists to design and assemble FPGA boards using 2-layer PCBs, breakout modules, and low-cost reflow methods like toaster ovens or hotplates. The article focuses on manufacturable PCB choices, netlist-driven workflows, and power/decoupling tactics that make high-density parts approachable for amateurs.
3 LEDs powered by fingers - puzzle
The post presents a compact electronics puzzle: a demonstration video that shows three LEDs reportedly powered by fingers. The author invites readers to watch the short movie and reverse-engineer the design, asking “How does it work?” rather than providing an explanation. The write-up targets hobbyists and circuit sleuths, prompting them to observe contact points, timing, and visible wiring, then form and test hypotheses about possible mechanisms. It frames the problem as an experimental challenge — encouraging hands-on verification, sharing measurements, and discussing candidate explanations such as conduction paths, coupling effects, or hidden circuitry — without revealing the solution, to stimulate community analysis and learning.
Series circuit - 3 LEDs
The post 'Series circuit - 3 LEDs' presents only a short prompt — "How does it work??? Solution:" — without any accompanying explanation, schematic, or component values. It therefore poses a clear question about the operation of three LEDs arranged in series but supplies no data to allow analysis. The entry functions as a request for a solution or follow-up discussion, implicitly asking for missing parameters such as supply voltage, LED forward voltages, and any current-limiting resistor. The post highlights the importance of including full circuit details when seeking help and invites contributors to provide the schematic or measurements needed to deliver a correct and practical explanation.
Video: The PN Junction. How Diodes Work?
The post points readers to a concise video that demonstrates the PN junction and explains how diodes work. Presented as a short endorsement, the author highlights the video’s visual approach as an accessible way to grasp fundamental semiconductor behavior. The entry serves as a quick recommendation for electronics students, hobbyists, and engineers seeking a visual primer on diode basics without an in-depth written tutorial. It frames the video as an engaging, easy-to-watch resource that complements technical study or classroom material, rather than replacing detailed textbooks or datasheets.
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.
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.
Lost Secrets of the H-Bridge, Part I: Ripple Current in Inductive Loads
Jason Sachs digs into what PWM switching actually does to current in an H-bridge with an inductive load, and why that ripple matters for motors and power converters. He derives closed-form ripple formulas, shows how to compute a reference current I_R0 = VDC·T/L, and uses Python and sympy to plot and verify results. Read it for practical rules to halve ripple and raise its frequency.
Feedback Controllers - Making Hardware with Firmware. Part 2. Ideal Model Examples
An engineer's guide to building ideal continuous-time models for hardware emulation, using TINA Spice, MATLAB and Simulink to validate controller and circuit behavior. The article shows how a passive R-C network can be emulated by an amplifier, a current measurement and a summer, with Spice, MATLAB and Simulink producing coincident Bode responses. Small phase differences between MATLAB and Simulink are noted, and sampled-data issues are slated for the next installment.
Oscilloscope review: Hameg HMO2024
Jason Sachs tests the Hameg HMO2024, a 200MHz 4-channel mixed-signal oscilloscope that promises Agilent-like features at a lower price. He finds strong analog noise performance, useful hi-res and zoom modes, and inexpensive serial-decode options, but warns of clumsy digital-input handling, awkward data-transfer software, and missing per-channel thresholds and Ethernet waveform export. The review helps budget-conscious embedded engineers weigh the trade-offs.
3 Good News
Stephane Boucher reports three quick wins for the EmbeddedRelated community: two sponsors have seeded a $1,000 rewards pool, the site now serves all pages over HTTPS, and the new forums have their first active discussions. If you want a share of the sponsor-funded rewards, jump into the forums and check the Vendors Directory for opportunities. Stay tuned for more updates.
Byte and Switch (Part 1)
Driving a 24V electromagnet from a 3.3V microcontroller looks trivial, but Jason Sachs shows how that simple switch can fail spectacularly. He walks through the cause of MOSFET destruction when an inductive load is turned off, and explains the practical fixes you actually need: a flyback diode, a gate series resistor, and a gate pulldown to keep the transistor well behaved.
Crowdfunding Articles?
Technical writers in the embedded world often have the expertise, but not always the time or incentive to turn it into a post. Stephane Boucher explores a crowdfunding model for technical articles, where readers would pledge small amounts to back promising abstracts before the writing begins. It is an interesting attempt to create more high quality EE content by paying authors upfront.
Finally got a drone!
Stephane Boucher finally bought a DJI Phantom 4 and found it does more than boost his video production value, it’s also hugely fun to fly. He used the drone for an aerial shot at SEGGER’s anniversary and for a beach project where kids drew a turtle while a separate camera captured a side timelapse. The post highlights creative shot combinations and a reminder to fly where it is legal.
10 Circuit Components You Should Know
Jason Sachs pulls together ten underrated but highly practical circuit components that every embedded engineer should know. From multifunction logic gates that act like a Swiss Army knife for glue logic to TL431 shunt regulators and tiny charge-pump inverters, each item is presented with real-world use cases and caveats. Read this to expand your parts toolbox and simplify future designs.
Which MOSFET topology?
Jason Sachs breaks down the four basic MOSFET topologies for switching a two-wire load, showing why low-side N-channel is usually the simplest and cheapest option. He explains why grounding or chassis return can force a high-side switch, how P-channel devices trade performance for simpler gate drive, and why high-side N-channel options need extra driver circuitry. He also stresses adding freewheeling diodes for inductive loads.
Feedback Controllers - Making Hardware with Firmware. Part 6. Self-Calibration Related.
Self-calibration is the missing piece that turns this mixed-signal hardware from a prototype into a usable instrument. In this installment, the author lays out how the board will measure itself, generate reference signals, and verify ADC and DAC behavior before the low-latency control firmware is built. The result is a practical framework for evaluation, production test, and routine self-test.
April is Oscilloscope Month: In Which We Discover Agilent Offers Us a Happy Deal and a Sad Name
Jason Sachs grabbed an MSOX3034 during Agilent's bandwidth deal, used a 30-day trial to debug UART issues, and then discovered Agilent's 'Happy Deal' lets you enable all MSOX software for the price of a single option. He walks through which MSOX3000 modules are worth buying, explains memory and waveform features, and delivers a wry take on the company's new Keysight name.
Short Takes (EE Shanty): What shall we do with a zero-ohm resistor?
When you need flexibility on a PCB, zero-ohm resistors are the obvious shortcut, but Jason M. Sachs shows why the label zero is misleading. He compares common SMT jumper specs, high-current specialty parts, and a practical workaround using 1 milliohm resistors to avoid voltage drop. Read this for a quick checklist to pick jumpers that actually carry your board's current.
Who else is going to Sensors Expo in San Jose? Looking for roommate(s)!
Stephane Boucher is heading to Sensors Expo in San Jose for the first time, and he is bringing cameras to capture demos and build a highlights video. He is also looking for roommates for a roomy Airbnb near the convention center, plus local tips for making the most of a free day in the Bay Area. If you are attending, there is also a registration discount code and a VIP pass giveaway in the mix.
Launch of EmbeddedRelated.tv
Stephane Boucher launches EmbeddedRelated.tv to host live broadcasts from Embedded World, starting next week. The site will show a constantly evolving schedule, a Live! tab to find ongoing streams, and ad-hoc demos added from the show floor. Expect schedule conflicts and small hiccups, and plan to refresh the page and join the forum thread for real-time updates and feedback.
Ancient History
Technology moves fast, and the tools, platforms, and assumptions you rely on can become outdated almost overnight. In this reflective post, the author contrasts the rapid evolution of embedded development with the much slower pace of social change, from programming turnaround times to the underrepresentation of women in engineering. It is a reminder to keep learning, but also to think about how we work and who gets included.
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.
3 Good News
Stephane Boucher reports three quick wins for the EmbeddedRelated community: two sponsors have seeded a $1,000 rewards pool, the site now serves all pages over HTTPS, and the new forums have their first active discussions. If you want a share of the sponsor-funded rewards, jump into the forums and check the Vendors Directory for opportunities. Stay tuned for more updates.
Feedback Controllers - Making Hardware with Firmware. Part 2. Ideal Model Examples
An engineer's guide to building ideal continuous-time models for hardware emulation, using TINA Spice, MATLAB and Simulink to validate controller and circuit behavior. The article shows how a passive R-C network can be emulated by an amplifier, a current measurement and a summer, with Spice, MATLAB and Simulink producing coincident Bode responses. Small phase differences between MATLAB and Simulink are noted, and sampled-data issues are slated for the next installment.
ESC Boston's Videos are Now Up
Stephane Boucher shares the videos he produced from ESC Boston, including a short highlight montage, a booth video for DLOGIC, and full talk clips from the conference. He also reflects on what he learned shooting on the show floor, especially the challenge of getting engineers on camera. It’s a quick behind-the-scenes look at technical event videography, with a preview of his next stop in Germany.
Feedback Controllers - Making Hardware with Firmware. Part 4. Engineering of Evaluation Hardware
This installment follows the hardware from concept to first power-up for a low-latency feedback controller and arbitrary circuit emulator. It walks through the practical engineering steps, from requirements, block diagrams, and issue tracking to component selection, simulation, PCB planning, purchasing, and staged bring-up. The result is a realistic look at how careful due diligence and a few trade-offs turned a research idea into working evaluation hardware.
Feedback Controllers - Making Hardware with Firmware. Part 3. Sampled Data Aspects
This article digs into practical sampled-data issues you must address when building feedback controllers for circuit emulation. It highlights a common MATLAB versus Simulink discrepancy caused by DAC holding, explains why FOH (ramp-invariant) c2d conversion matters, and surveys latency, bit depth, filter and precision trade-offs. It also lists candidate ADCs, DACs and FPGAs used in a real evaluation platform to guide hardware choices.
