Jack Ganssle

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consultant

Jack G. Ganssle is a lecturer and consultant on embedded development issues. He conducts seminars on embedded systems and helps companies with their embedded challenges. Contact him at jack@ganssle.com. His website is www.ganssle.com.

JackGanssle

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    • Schematics.com offers a free schematic editor for those who wish to share their designs.

    • Hacker, Maker… do these neologisms imply only a facile level of understanding?

    • Agile luminary Ron Jeffries thinks it’s wrong to estimate schedules. Is it?

    • snprintf() is generally preferable to sprintf().

    • The new education mantra is “Learn to code.” I disagree.

    • Rich, A lot of it was ground bounce that caused incorrect latching. As an electronics technician in high school in the late 60s I was taught that "ground is ground the world around." Unfortunately, it's not. Reactance in PCB tracks limits how fast energy can be transferred. Jack

    • That's a great link! Thanks for making my day.

    • By this I mean that one should not count errors detected by the compiler. Compile the code, fix all of the problems it finds, and count all subsequent errors.

    • Charles, You're right. The 10**-15 error is some sort of transcription mistake going from Word to HTML. The 0.18 nA is my goof. Thanks! Jack

    • This is a very difficult issue. Some on-chip brownout detectors require far more current than the MCU core does in sleep mode. Writing to flash usually takes quite a lot of energy. And holding up the power using a capacitor will (probably) not work. If you do the time constant math, it will take a sizable cap, and the cap's leakage is proportional to it's size in Farads. So a big enough cap will probably leak more microamps than the MCU uses when sleeping. You'll have to use a ceramic cap (tantalums leak like an NSA whistleblower), and for some of the analysis I have done either it's impossible to get a cap of the required size, or it will cost $10 or more. I'll cover these issues more deeply in a future article.

    • Yes, Marcus tells me their ISP is having trouble this week. I know he and his people are working furiously to get it back up.

    • I walked into the house today and my wife told me her sister-in-law had called from the car, but suddenly, while talking, sideswiped a car, on a high bridge over a river. 5 minutes later she called again: now she was still on the bridge, still driving, following the other car and a cop to a safe spot!