Jack's Articles

Bring this class to your company! Click here to find how we can come to your facility and present the class.

Articles by Title (go here for articles by subject area)

8 and 16 Bit Microcontrollers - A look at the state of smaller CPUs
10 Years After - My 120th column for ESP and what I've learned
386 Protected Mode - Part 1 of a two part article about protected mode.
386 Protected Mode - Part 2 of a two part article about protected mode

A Boss's Quick Start to Firmware Engineering, Part 1 - Most bosses don't understand the issues involved in producing great firmware. Show them this.
A Boss's Quick Start to Firmware Engineering, Part 2 - Show them more.
A Different Take on Asserts - The assert is a well-known proactive debugging tool. Why not extend the concept to deal with real-time issues.
A Look Back - A look at the history of our industry
A Matter of Style - We tend to be bad a living up to promises we make - even to ourselves. It's important to change the whole approach.
A Plea to Compiler Vendors - Compilers miss the mark on real-time issues
A Value Proposition - Unfulfilled.
ARRLHandbooks - A review of one of the finest hardware handbooks.
An Embedded Life - Jack looks back on 30 years of building embedded systems.
An Example of Foolishness - Jack lays out the basic rules of troubleshooting anything.
An OS in a Can - Using a commercial RTOS will save big bucks... and is rather fun.
April Fools - Do you have a backup strategy?
At Sea - Embedded Systems at sea
As Good As It Gets - Why is it so hard to build great code? Musings on software failures.
Assigning the Blame - End each project with a Postmortem; feedback stabilizes systems!
Asynchronous Hardware-Firmware - External events that are changing (analog inputs, timers, encoders and many other sources) often sometimes confuse the code. Few developers understand how to read these simple inputs reliably.
Awesome Functions - How to write a clean, tight and bug-free function.

Bailing Frantically - In panic mode? You'll never exit it till you take time to stop bailing and plug the leaks.
Banking Basics - Ideas to help you expand your system's address space.
Beginner's Corner - In-Circuit-Emulators - A beginner's guide to the best debugging tool of all, the in-circuit emulator.
Beginner's Corner - Reentrancy - A beginner's guide to reentrancy issues.
Big Systems - Another piece on using x86 Protected Mode.
Bit Banging - You don't need a UART to send and receive serial data. Software alone suffices. Here's the code.
Boolean Algebra - Do you get the boolean blues? Those hardware weenies keep chatting about DeMorgan, truth and evil... and you're feeling left out? Read on.
Boss Management - Bosses need to be managed too.
Built-in Debuggers - More and more processors have built-in debugging resources. Here's a look at what features they offer.
Built-In Diagnostics - No system is useful unless it can be built in production. Add simple diagnostics.
Bus Cycles - Software folks need to understand how a microprocessor handles data on its busses. Here's the short intro.
Business 101 - You can't be an effective engineer unless you understand how your engineering role impacts the business as a whole. Step back, get a new zeitgeist, and expand your horizons a bit.

C for Microcontrollers - This article discusses the state of C for controllers circa 1990.
Call Me Ishmaell - Lessons from failures on a small boat at sea.
Chaotic Systems - The new science of chaos is fascinating in its own right, and may have important implications for designers of embedded systems.
Coding ISRs - Handling interrupts is tricky at best. Here's a few suggestions.
Comments on Commenting - Rules for creating awesome comments in your code.
Computing CRCs in Parallel - How to use a PLD to figure CRCs in a single clock cycle.
Convolutions - Convolutions are a really cool way to smooth and even differentiate data. You gotta check this out.
Crash and Burn - Disasters, and what we can learn

Data Compression - Transmission bandwidth is always limited (hey... if you're reading this over a 28.8kb link, you get the picture!). Data compression can help a lot.
Dear Abbey - Abbey talks to developers about building embedded systems.
Debuggable designs - Tips for improving hardware designs
Debugging ISRs - Part 1 - This is part 1 of a two part series on debugging interrupt service routines.
Debugging ISRs - Part 2 - This is part 2 of a two part series on debugging interrupt service routines.
Deconstructing XP - eXtreme Programming has some fabulous ideas. And some really dumb ones. This is a review of two XP books.
Depot Repair - Thoughts on our throwaway economy, and our role in it.
Design For Performance - Make the system as fast as it needs to be!
Digital Engineering is More Fun - Core memory was all we had years ago. It's interesting stuff.
Disaster - A description of some embedded disasters, and what we can learn from them.
DMA - Too many of us don't really understand DMA. Read on...
Do You Need A Degree - Is a degree needed? Useful?
Drawing Systems - Most small companies never organize their drawings in a logical fashion, and instead all-too-often rely on memory when building production units. Here's an easy system that will get your drawings in order.
DSP - An introduction to Digital Signal Processing.

Electromagnetics for Firmware People - Maxwell's Laws really are important for firmware development. Here is an introduction.
Embedded Lingos - How do you pick a language? Here's some thoughts about C++
Embedded Trig - Here's some algorithms to make it easier to compute complex trig functions.
Emulators - The basics of the In-Circuit Emulator
Encoders - Want to learn more about measuring position? Read this article.
Engineering Ethics - We enginers build systems that profoundly impact people's lives. Strong ethics are the most important tool we have to keep our customers safe from misbehaving products.
Extreme Embedded - A look at eXtreme Programming.

Fire Code For Software - As a collector of software disasters, I have to ask, why is there no fire code for software?
Firmware Disasters - Test like you fly, fly what you have tested.
Firmware Disasters Redux! - Those who forget history are condemned to repeat it.

Green Motor Control - As a designer, you can make decisions that greatly impact the environment. Here's how to save energy.
Guardian Angels - Every project needs a guardian angel, someone who watches over the code.

Habits - The 7 Habits of Highly Dysfunctional Developers
Hardware for Better Firmware - A few changes to the system's hardware design can greatly improve the code.
How Microsoft Saved The World - The Big Bad Beast or a a force of good? Jack's inviting flames by claiming that without Microsoft we would still be computing on our fingers and toes.
Huge Data on the Z180 - The Z180's banking scheme is great for handling code; data is a bit more complex. Here's example code.

I, Consultant (part 1) - Here's how to get rich quick: quit your job, become a consultant, and charge $90/hour. NOT!
I, Consultant (part 2) - This is a follow-on the the previous article. Stay tuned for part 3.
I, Consultant (part 3) - Yet another followup
I, Consultant (part 4) - The last followup... I sure hope.
I, Consultant (part 5) - The last followup. Fer Sure.
Interactive Design - Build your system incrementally. Here's some tips.
Interrupt Latency - Do you really know what latency is? Where it comes from? How to measure it? Here's guidelines.
Interrupt Predictability - How do you know if your ISRs will be fast enough?
Is Hardware Reliable - How reliable is hardware anyway? Intel's telling us not to expect our CPUs to actually work . . .

Jack's Rules of Thumb - Engineers use rules of thumb to quickly estimate rather than do detailed calculations. Firmware can benefit from the same idea. Here's a sampling of such rules.
Jake Busts Out - Jake busts out of jail to help the VCs get a product to market.
Java - Ready for Prime Time? - Is Java really the next silver bullet for embedded programming?

Keep it Small - Get the product out faster by better partitioning
Kids - In praise of kids these days
Kids These Days - Back in my day, we had to build our own equipment

Language Selection - Thoughts on selecting a programming language
Lies, Damn Lies, and Schedules - Schedules fail for a lot of reasons, one of which is rampant dishonesty.
Living to Learn - A philosophy of never having to say you're done with school
Longevity Planning - Do you have a backup system?

Magic - an article about our society's inability to embrace the new technologies we techies create.
Measuring Bugs - If you don't measure bug rates you'll never improve your coding. Besides, the right measures will accelerate the schedule.
Memo To My Boss - Jake Schmidt quits and fires off a memo to his ex-boss. It's flaming, but full of useful lessons.
Memorial Day - Years in the future a wealthy man looks back on how the embedded world collapsed.
Memory as a Device - Clever use of memory devices can really enhance your products.
Metastability and Firmware - A very subtle reentrancy-like situation develops when software needs two or more reads of hardware to input a value.
Minimizing Analog Noise - Analog noise is a tough problem. Here are a few ways to minimize it.
Momisms - Things your mom should have taught you

New Hardware - Suggestions for bringing up a new hardware design.
Non-Degreed Engineers - How important is a degree in this industry?
Non-Volatile RAM - How to manage battery backed up RAM

On Management - Thoughts on managing development
On Measurements - Managers chant "If you can't measure it, you can't manage it." What should we measure in firmware development?
Open Source? - Opening the open source debate
Oscilloscope Upate - The wise embedded engineer will be a master of many tools. The scope is one of the most important.

Passion and the Developer - Use reason, not emotions.
Perform or Perish - How do you deal with software performance problems?
Picking a CPU - How do you decide what CPU to use? Here's some factors to consider.
Pipelines and Prefetchers - All modern processors use pipelines and/or prefetchers to increase performance. Here's how they work.
Position Encoders - Encoders transmit position or frequency info to the computer. Here's a few ways to make life with them easier.
Proactive Debugging - Seed your code with simple tricks to find bugs
Programming Style - Programming style is just as important as any other parameter that goes into a coding task. Here are a few ideas, rants, and raves.
Promise Management - We make lots of promises to our boss, our employees, spouse and children. Promises are a sort of social currency. Manage them properly or they'll lose their value.
Prototyping with SMT - One person's experience with using SMT devices on prototypes.

Radio Days - Radios and noise reduction
Read That Datasheet - Never assume a part has certain electrical or timing parameters. Often little surprises lurk. Did you know that virtually all microprocessors do not accept TTL levels for clock and reset?
Real Time - The basics of real-time programming
Reentrancy - Most real time systems require a certain amount of reentrant code, yet too many programmers have no idea what this entails
Refreshing Software - Refresh is yet one more thing that software can, in some situation, replace.
Religious Wars - Choosing a programming language is a place where people often get really dysfunctional.
Relocatable Code - Some embedded code must run at more than on address.
Resistors - Be careful how you design resistors and R-packs into your digital circuits. This article tells how.

Sailing stories, linked here by popular demand
Schedule Madness - Most schedules are dysfunctional
Scheduling - It is possible to create accurate schedules, here's how.
Self Calibrating Systems - Here's an algorithm to make an instrument read correct values without ever manually setting gain and offset coefficients.
Sell Yourself - Guidelines for writing a resume.
Serial Data Transmission - Here's a primer to using UARTs in embedded systems.
Shared Perceptions - On a stop in Bermuda, Jack meets a wizened ex-developer. Over too many drinks several interesting lessons emerge.
Small is Beautiful - Small Processors dominate this industry. This is why.
Smoothing Digital Inputs - There's a lot of way ways to debounce digital inputs. A few are listed in this article.
Speed Kills - Data comm over cheap serial links might be more cost effective than other, faster, options.
Survival of the Fittest - Do you work hard? How about smart? This article might make you mad, but hopefully it's start some ideas flowing. Feel free to send flames to us via email!

Taming Analog Noise - Here's a few ways to use smart software to reduce the amount of noise in your system.
Testing RAM - How to test system RAM.
Thanks for the Memories - Here's some advice about testing RAM and ROMs in your embedded system.
The C Blues - C is still a long way from what we embedded folks need in a language. Here's some ideas and complaints.
The Case of the Crashing 68000 - a fun detective story about embedded systems
The Future of Embedded Programming - Here's a set of prognostications about programming in the future. Read 'em and weep.
The Good Guys - Here are a few great products for managing spam, backups, network security, and even a cool CAD package.
The ICE Blues - Using an emulator? Here are some gotchas to watch out for.
The Olden Days - Before CAD we pushed our pencils in the snow, uphill both ways.
The Organized Bench - Lab pigs beware! This is your 12 step plan to recovery.
The Perils of NMI - NMI is a critical resource, yet all too often it's misused.
The Secret of My Success - Our hero takes on another project... heh heh
The Tao of Diagnostics - part 2 of a two part series on embedded diagnostics
The Vote - This article, written in 2002, discusses how Bubba "the can man" won the 2004 presidential election.
The Zen of Diagnostics - part 1 of a two part series on embedded diagnostics
The Z80 Lives! - The Z80 and its derivatives continues to be tremendously successful. Here's the current state of the art.
Toastal Lessons - Our hero designs a mechanical toaster, that morphs into a net-connecte 32 bit monster
Tool Quest - Decent tools have less than zero cost... if you make more than a dollar an hour.
Tools For Clean Code - There are a lot of tools around that will automatically check our code. Efficient developers automate everything they can. Experts know that firmware is so expensive that any code-auditing tool is a great thing.
Tricks of the Trade - Troubleshooting hints and kinks.
Troubleshooting - Troubleshooting is a mental exercise requiring a firm grasp of the technical concepts involved, along with the right philosophy.
Troubleshooting 101 - Troubleshooting is more art than science. Here's some ideas.

USB - An overview of embedded USB
Understand Your User's Needs - Understand your user's needs; only then can you be sure the code is useful, as well as correct.
Using the Z180 MMU - Extend your Z80 address spaces to 1 Mb with the Z180.

Vanishing Visibility - Smaller CPUs create all sorts of tool issues.
VCO Based Sensors - VCOs can form a clever way to digitize analog data.

Wandering Pointers - Code crashes and dangling pointer tips
What Goes In Must Come Out - FIFOs are hardware analogs of a sort of reverse stack. Here's how they work.
What Happens at 100Mhz? - At very high speeds we'll have to change debugging strategies. Here's some ideas.
When the Thrill is Gone - Life has a funny way of changing the obvious...

The Ganssle Group - PO Box 38346, Baltimore, MD 21231 - 410-504-6660