Troubleshooting notes from days past, TTL, Linear
Troubleshooting electronics is more about thinking than tools, yet details matter. This concise collection of technician notes condenses practical procedures and probe precautions, IC failure modes, digital logic diagnostics, and common power-supply traps. Drawn from classic guides by Frank R. Dungan and James Perozzo, it provides a methodical checklist to isolate faults faster and avoid costly mistakes when repairing embedded hardware.
New 8Gb DDR3 components from Intelligent Memory
Intelligent Memory has expanded its DDR3L lineup with new 8Gb devices in x4, x8, and x16 configurations. The parts support both 1.35V DDR3L operation and backward-compatible 1.5V DDR3 use, with commercial and industrial temperature options. The announcement also includes refreshed 16GB UDIMM and SO-DIMM modules, plus server-oriented RDIMM and Mini RDIMM offerings.
Interfacing with Electrochemical Gas Sensors
Stephane Boucher lays out practical rules for connecting electrochemical gas sensors to amplifiers and mixed-signal MCUs. He explains the potentiostat and transimpedance amplifier topology, why the reference electrode must see sub-nanoamp currents, and how GPIO structures in devices like the PSoC 4 can introduce leakage. The post shows how choosing supply and reference voltages yields a near-zero input-current operating point for reliable sensing.
Circuit Board Standoffs
Can't find the exact standoff size for your PCB? This post shows how to fabricate custom standoffs from tubing or solid rod, with practical guidance on material choices, measurement, cutting, lathe facing, and drilling and tapping. The walkthrough uses brass as an accessible option, lists the correct drill size for 4-40 screws, and explains how to create chassis threads if needed.
Designing IoT Wireless Sensor Nodes
Mahesh Balan outlines practical strategies for building tiny IoT wireless sensor nodes that run on harvested energy. The post explains using small solar cells with coin-cell or supercapacitor buffering, pairing sensors with Bluetooth Low Energy for short-range telemetry, and choosing PMICs with ultra-low quiescent and startup power. A Cypress PMIC example shows operation can be sustained under low-brightness conditions near 100 lx.
Intel 8088 - A blast from the past
The Intel 8088 is a reminder of how hands-on early microcomputer work really was. This short retrospective looks back at wire-wrapping, perfboard construction, and assembly language programming on a board built around the 8088 and its support chips. It is a fun contrast to today’s Raspberry Pi era, where far more performance comes in a sealed package you can’t build yourself.
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.
It ain't heavy, it's my robot...
For anyone building a man-portable unmanned ground vehicle this post collects practical design constraints and mission trade-offs engineers actually face. It summarizes weight and cost classes, locomotion options from throwables to wheeled skid-steers, sensor and camera requirements, power and battery strategies, communications range, and field-repair issues. Use it as a checklist to match platform choices to intended tasks and environments.
Unmanned Ground Vehicles - Design Considerations for Snow and Cold Environments
Winter conditions expose UGV weaknesses: snow, ice and extreme cold change traction, sensor performance, batteries and lubrication. This post walks through snow mechanics, ground-pressure tradeoffs for wheels versus tracks, and practical mitigations like heaters, insulation, sensor covers and low-temperature lubricants. If you design autonomous ground systems for cold climates, these engineering checks and referenced studies will help you avoid mission-ending failures.
Choosing a Microcontroller for Your Vehicle
Picking the right microcontroller can make or break an autonomous vehicle project, and this post gives a practical checklist to help. It walks through voltage and power needs, memory and IO planning, cost and availability tradeoffs, and when to step up from an 8-bit MCU to a 32-bit controller or single-board computer. Real-world board examples illustrate the choices.
Beware of Analog Switch Leakage Current
Leakage currents in analog switches can quietly wreck precision reference circuits at elevated temperature. Jason M. Sachs walks through three switch-topology implementations for a switchable 1.25 V reference and shows which topology gives the smallest worst-case output error using real part specs. He explains why op amp input bias is usually negligible and gives practical fixes: lower resistances, better switches, or limiting temperature range.
Thermistor signal conditioning: Dos and Don'ts, Tips and Tricks
Jason Sachs shows how to keep thermistor conditioning simple and accurate for embedded systems. He warns against analog linearization and excessive analog stages, and explains why ratiometric dividers, proper ADC buffering, and using the same reference voltage give better results. The post also covers thermal pitfalls like self-heating and lead conduction, plus practical tips for ADC autocalibration and polynomial temperature conversion.
Metal detection: building the detector
Fabien Le Mentec turns a bench-validated BFO stage into a field-ready metal detector using scavenged parts and straightforward fabrication. He moves the circuit from breadboard to a through-hole prototyping PCB, swaps the Arduino Nano for a lower-power Mini, and builds an ABS control box with buttons and a buzzer. The build uses a 2S LiPo pack with a 5V LDO and a nonmagnetic coil mount, with practical notes on tradeoffs and safety.
Basic hand tools for electronics assembly
Though the software tools vary with different microcontrollers, many hardware tools are the same.
Metal detection: beat frequency oscillator
Fabien Le Mentec walks through a practical beat frequency oscillator metal detector, from the LC oscillator theory to the Arduino-based frequency counter. He shows how changes in coil inductance reveal nearby metal, and why capacitor choice matters when you want a stable detector. The post focuses on the BFO sensing stage, with enough detail to help you build and test one yourself.
OS influence on power consumption
Power consumption of an embedded system may be influenced in software in general, but selection of an operating system can be key.
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.
Analog-to-Digital Confusion: Pitfalls of Driving an ADC
Wayne's thermistor board showed one ADC channel changing when another was heated, a classic case of ADC input cross-coupling. The post walks through how multiplexed ADCs, the small sample-and-hold capacitor, source impedance, sampling time, repeated sampling rates, and added charge reservoirs interact to create errors. Learn practical fixes including increasing sample time, sizing external caps, adding op-amp buffers, and using an RC dampener with PCB layout tips.
Voltage Drops Are Falling on My Head: Operating Points, Linearization, Temperature Coefficients, and Thermal Runaway
A lot of the neat, tidy diode and transistor rules you learned in school are really just approximations. Jason Sachs shows how operating points, linearization, and temperature coefficients give you a better mental model for real circuits, then uses that framework to explain why thermal runaway happens. Along the way, he connects the theory to practical device behavior, op-amp output stages, and the design tricks that keep parts from letting out the magic smoke.
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.
How to Analyze a Differential Amplifier
Jason Sachs walks through the algebra and intuition behind the classic four-resistor differential amplifier. He derives the exact output equation, isolates error terms from resistor mismatch and op-amp imperfections, and explains why common-mode gain depends on mismatch not on the differential gain. Read this for clear formulas, modal insight into common-mode versus differential-mode, and practical steps to reduce offsets in real designs.
Optimizing Optoisolators, and Other Stories of Making Do With Less
Jason Sachs digs into how to squeeze speed and reliability from low-cost optoisolators, showing practical tweaks that often outperform default datasheet usage. He mixes hands-on circuits — using 4N35 base-emitter resistors, Schottky clamps, input speedup caps, and output buffering — with transistor-switching theory and a cautionary production story to show when to optimize and when to splurge on pricier isolators.
Stairway to Thévenin
Jason Sachs strips away classroom mystique to show how Thevenin and Norton equivalents are practical tools for real embedded work. Using a simple two-terminal black-box example he shows how two measurements give Vth and Rth, then applies that model to voltage-divider references, potentiometer RC filters, and combining multiple sources with Millman's theorem. Read it for fast, practical ways to predict output impedance, droop, and filter time constants.
Metal detection: beat frequency oscillator
Fabien Le Mentec walks through a practical beat frequency oscillator metal detector, from the LC oscillator theory to the Arduino-based frequency counter. He shows how changes in coil inductance reveal nearby metal, and why capacitor choice matters when you want a stable detector. The post focuses on the BFO sensing stage, with enough detail to help you build and test one yourself.
Basic hand tools for electronics assembly
Though the software tools vary with different microcontrollers, many hardware tools are the same.
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.
Isolated Sigma-Delta Modulators, Rah Rah Rah!
Analog isolation can blow up DAQ budgets, but isolated sigma-delta modulators let you send a single 1-bit stream and a clock across the barrier, keeping costs down. Jason walks through Avago, TI, and Analog Devices parts, explains sigma-delta noise shaping in plain terms, and calls out the real engineering work: converting a 10–20 MHz bitstream into usable samples with sinc/CIC decimators or FPGA filtering.
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.
A wireless door monitor based on the BANO framework
Fabien Le Mentec built a battery-powered wireless door monitor and a reusable node framework called BANO to monitor doors across seven floors without wired links. The post highlights BANO's 17-byte key,value protocol, the node runtime that enables wake-on-interrupt low-power operation, and practical RF choices like the NRF905 plus a 330 µF cap to handle coin-cell transmission peaks. It includes source, PCB, and base station notes.
Have You Ever Seen an Ideal Op-Amp?
Forget the ideal op-amp fantasy, Jason Sachs walks through the practical nonidealities that make textbook gain formulas fail in real circuits. Using the uA741C and TLC081C as examples, he explains offset voltage, input bias and offset currents, common-mode and supply rejection, gain-bandwidth and slew-rate limits, plus capacitive loading, RF rectification and overload recovery. Read to learn which datasheet specs matter and why.
