Video-Based STEM Embedded Systems Curriculum, Part 2
Part 2 delivers three ready-to-run lesson plans for a video-based STEM embedded course, starting with Arduino hands-on projects using an Elegoo UNO starter kit and Bryan Vines video walkthroughs that explain the code. It then teaches Fritzing for pictorial and schematic circuit drawings, followed by Collin Cunningham videos that cover resistors, capacitors, transistors, schematics, and other core components. The sequence stresses design, draw, build, test to keep students engaged.
Video-Based STEM Embedded Systems Curriculum, Part 1
This curriculum shows how to teach introductory embedded systems using free online videos and low-cost kits, suitable for middle-school, high-school, college, or adult learners. It packages curated educator recommendations, a per-student equipment and book list, essential free software, and core lesson topics like Arduino, MicroPython, Kicad board design, soldering, and RTOS basics. The approach stresses hands-on labs, safety, backups, mentorship, and adapting to local budgets.
Definite Article: Notes on Traceability
Traceability sounds bureaucratic until you need to identify a mystery part, a board revision, or the exact firmware that was shipped years ago. Jason Sachs shows how it applies across hardware, software, testing, and documentation, from Digi-Key’s cut-tape part tracing to device IDs, build metadata, and precise test records. The message is simple: if you cannot prove what something is and where it came from, you are flying blind.
Tolerance Analysis
Jason Sachs walks through practical tolerance analysis by designing a 24V overvoltage detector from the ground up, combining resistor tolerances, temperature coefficients, reference and comparator errors, hysteresis, and dynamic RC behavior. He demonstrates worst-case stacking with real datasheet numbers, shows how solder and mechanical stress affect resistor choice, and sizes filtering so the comparator meets a microsecond-range trip requirement. The article is a hands-on guide full of worked examples and trade-offs for embedded hardware engineers.
Racing to Sleep
Jason Sachs walks through a realistic field sensor case study, the BigBrotherBear 2000, to show how a careful power budget exposes surprising energy costs. He demonstrates that radios and data transmission often dwarf quiescent MCU current, explains the race-to-sleep principle for computation-bound tasks, and outlines practical wake-up and measurement trade-offs so engineers can extend battery lifetime in real deployments.
Wye Delta Tee Pi: Observations on Three-Terminal Networks
Three-terminal passive networks, wye, delta, tee, and pi, are more interchangeable than many engineers expect. Jason Sachs walks through Kennelly's wye-delta formulas, Z and Y matrix representations for tee and pi two-port networks, and worked examples ranging from balanced to highly skewed impedances. The post highlights practical payoffs, including using topology transforms to substitute hard-to-source capacitors with simpler, precision-friendly parts.
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.
Servo Troubleshooting notes
Most noisy, jittery, or hot servos turn out to be mechanical or power issues, not mysterious failures. This short checklist lists common servo malfunctions, probable causes, and straightforward corrective actions, covering gear wear, potentiometer contamination, underpowered or overloaded servos, wiring and battery problems, and alignment faults. Keep it handy when troubleshooting hobby or small robotics servos to speed repairs and avoid further damage.
R1C1R2C2: The Two-Pole Passive RC Filter
Jason Sachs walks through the math and simulation for the common two-pole passive RC filter, turning repetitive algebra into a compact reference you can reuse. He derives the closed-form transfer function, extracts the natural frequency and damping ratio, and explains why the topology cannot be underdamped without inductors or active stages. The post finishes with a state-space simulation recipe and practical component guidance.
Making a connection 1
Reliable electrical connections are the unsung foundation of any embedded system, yet connector selection and technique are often overlooked. This practical primer walks through common terminal styles, when to solder versus crimp, basic crimping steps and tool choices, plus simple checks and color-coding rules to help you make durable, serviceable wire connections without surprises.
R1C1R2C2: The Two-Pole Passive RC Filter
Jason Sachs walks through the math and simulation for the common two-pole passive RC filter, turning repetitive algebra into a compact reference you can reuse. He derives the closed-form transfer function, extracts the natural frequency and damping ratio, and explains why the topology cannot be underdamped without inductors or active stages. The post finishes with a state-space simulation recipe and practical component guidance.
Arduino robotics #2 - chassis, locomotion and power
Lonnie Honeycutt walks through building Clusterbot's round differential-drive chassis, showing how a circular base and Tamiya gearbox simplify turning and torque tradeoffs. The post covers motor selection, wheel fit, balance issues, and a practical two-battery power arrangement with VMOT for the motors and a separate 9V for the Arduino. Expect hands-on tips and lessons learned from a first-time robot build.
Video-Based STEM Embedded Systems Curriculum, Part 2
Part 2 delivers three ready-to-run lesson plans for a video-based STEM embedded course, starting with Arduino hands-on projects using an Elegoo UNO starter kit and Bryan Vines video walkthroughs that explain the code. It then teaches Fritzing for pictorial and schematic circuit drawings, followed by Collin Cunningham videos that cover resistors, capacitors, transistors, schematics, and other core components. The sequence stresses design, draw, build, test to keep students engaged.
Making a connection 1
Reliable electrical connections are the unsung foundation of any embedded system, yet connector selection and technique are often overlooked. This practical primer walks through common terminal styles, when to solder versus crimp, basic crimping steps and tool choices, plus simple checks and color-coding rules to help you make durable, serviceable wire connections without surprises.
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.
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.
Here Comes The Noise!
Noise. That awful thing which nobody wants that most sadly never learn about. It's time to change that with this blog post.
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.
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.
Introduction to Microcontrollers - Adding Some Real-World Hardware
Two blinking LEDs only teach you so much, so Mike designed a docking board that adds a 4x20 HD44780 LCD, a 4x4 button matrix, four LEDs, DIP switches and an ADC potentiometer for AVR and STM32 experiments. This post shows how to wire and drive the HD44780 in 4-bit mode, calibrate microsecond and millisecond software delays, use the busy flag to speed writes, and includes AVR example code to get the display running.
The Other Kind of Bypass Capacitor
Most engineers treat bypass capacitors as supply decoupling, but Jason Sachs digs into the other kind: a capacitor placed in the feedback path to tame unpredictable high-frequency plant behavior. He walks through real examples, Bode plots, and a simple RC model to show how the cap forces unity-gain feedback at high frequency, stabilizing switching regulators and wideband amplifiers while revealing the speed versus stability tradeoff.
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.
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.
Levitating Globe Teardown, Part 1
Tim Wescott buys a $30 floating-globe desk toy and walks through first impressions, hands-on magnet experiments, and a frank critique of its control system. He highlights the toy's underdamped response, uni-polar electromagnet tradeoffs, and simple hacks that reveal clues about the pole pieces and magnet layout. This is a practical, engineer-forward preview before the actual teardown in part two.
First-Order Systems: The Happy Family
Jason Sachs takes the modest topic of first-order systems and makes it useful, showing how RC filters behave in both time and frequency domains and why they all share the same shape. He steps through step, ramp, and sinusoidal responses, explains poles, zeros, and Bode behavior, and uses Python plots to make tracking error and the role of tau easy to visualize.
Introduction to Microcontrollers - Adding Some Real-World Hardware
Two blinking LEDs only teach you so much, so Mike designed a docking board that adds a 4x20 HD44780 LCD, a 4x4 button matrix, four LEDs, DIP switches and an ADC potentiometer for AVR and STM32 experiments. This post shows how to wire and drive the HD44780 in 4-bit mode, calibrate microsecond and millisecond software delays, use the busy flag to speed writes, and includes AVR example code to get the display running.
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.
Levitating Globe Teardown, Part 2
Tim Wescott opens up a budget levitating globe and shows why it seems magical: a massive 30 mm rare-earth magnet and a deliberately cheap magnetic circuit. He documents a bolt used as the flux core, a likely microcontroller and hall sensor in the head, very fine winding in the electromagnet, and a single-transistor unidirectional drive. Part 3 will measure forces and sensor voltages to build a better controller.
10 More (Obscure) Circuit Components You Should Know
Jason Sachs follows up his earlier primer with ten more underused but practical parts that can simplify embedded hardware designs. From MOSFET-based ideal diode controllers that eliminate diode drops to TAOS light-to-frequency sensors that expand dynamic range, the post explains what each component does, when to choose it, and real-world tradeoffs learned from field use. Ideal for engineers looking to broaden their parts toolbox.
10 Items of Test Equipment You Should Know
Jason Sachs walks through ten often-overlooked pieces of test gear that make debugging embedded hardware faster, safer, and more precise. From clamp-on and Rogowski current probes to spring-tip probes, IC test clips, and compact DAQ systems, each tool targets a common bench frustration. Practical buying notes and use cases help you choose tools that save time and reduce guesswork.














