Thursday, October 24, 2019

Mac High Sierra fresh install errors on DIY Fusion Drive

As a follow-up to my installation of a DIY Fusion Drive on the 2011 Mac mini, there are some clarifications that have become useful a few years later on. I wanted to reformat the drives with a fresh operating system to pass along the computer to a family member, but was getting errors during installation.

The bottom line is that the install process does not work on a freshly-created Fusion Drive, but you can get around this by restoring a Time Machine backup onto the new Fusion Drive. Along the way, I discovered how to make a DIY Fusion Drive with a properly working recovery partition for troubleshooting in the future. The 2011 Mac mini only supports up to macOS High Sierra, though I suspect this is all resolved in Mojave/Catalina thanks to the luxuriously simple "diskutil resetFusion" command that I was able to use on a 2014 machine.

The issue is that the macOS High Sierra installer will give errors when doing a clean installation on a DIY Fusion Drive system, reporting either “macOS could not be installed on your system - invalid request” or “the installer resources were not found”. I got nervous because I was already in Recovery mode and a fresh install was failing... was the computer just toast now?!?

First comes the "invalid request" error
And if you reboot, you get "the installer resources were not found"
It turns out that the solution is to split the drives up, do a regular install onto the hard drive, use that to create a Time Machine backup, then rebuild the Fusion drive, and restore the backup (i.e. NOT a new install). Phew! (Thanks to this thread for pointing me in the right direction.) OK let’s do this in detail:

Wednesday, May 29, 2019

Engineering's Unwritten Rules

When I was at a large company managing diesel engine testing and development, my director passed along the following document he called "Engineering's Unwritten Rules". It really resonated with me because it solidified so many thoughts I had had for years.

I suspect many engineers have a similar story of documents like this being passed down through the (workforce) generations, because through some googling I found out that this was actually someone's summary of a series of three articles from 1944 by W. J. King, originally published in Mechanical Engineering magazine as "The Unwritten Laws of Engineering". (The full document has since been made available for purchase via ASME and includes some modern updates. A scanned older version is also available on Google Books.)

The Unwritten Rules of Engineering

Regardless, what I received years ago was a nice document on its own, though was surely modified by a few people over the decades. It focuses on the first portion of the original article series, on the successful behaviors of new engineers. It is presented here with minimal modification [with additions by Mike in brackets]:

Monday, November 26, 2018

Book Review—Thinking in Bets by Annie Duke

Thinking in Bets (Making Smarter Decisions When You Don't Have All the Facts) has been a wildly popular book, and I can see why. I was really excited about the prospects—who isn’t interested in better decision making? And as an engineer, finding that balance between gathering enough info and taking action is a key career skill we can all improve. Did this book deliver? Partly.

Wednesday, November 7, 2018

Soto Pocket Torch Troubleshooting for No Flame or Weak Flame

If your Soto Pocket Torch has stopped working, or the flame is small or weak, this guide can probably help you fix it -- it's likely not broken! The Soto PT-14SB torch is a great tool for camping, backpacking, and around the house for lighting candles and sealing rope ends. It uses disposable lighters instead of a fuel reservoir, so there is no fussing with refills and more fuel is always available at the local convenience store. I’ve seen two problems occur over the years: small/weak flames, and no flame at all.
A good flame!

Monday, January 1, 2018

Book Review—Eat That Frog! by Brian Tracy

Eat That Frog! is a pithy business success book that is effective and short. Basic premise: begin each day with the most important and difficult task that will have the greatest impact on your job and life. After that, everything will seem easy in comparison.

"It has been said that if the first thing you do each morning is to eat a live frog, you can go through the day with the satisfaction of knowing that that is probably the worst thing that is going to happen to you all day long.

Your “frog” is your biggest, most important task, the one you are most likely to procrastinate on if you don’t do something about it. It is also the one task that can have the greatest positive impact on your life and results at the moment."

Thursday, December 29, 2016

Make an Old-school two-way pager with Arduino

I made a 2-way pager with an Arduino, GSM shield, and LCD shield. I’ve found this idea to be more useful than at first glance—I designed it so it could be used by children in lieu of a real cell phone, or it could be used as an “SOS” button for someone working alone outdoors or even exercising (if it was a bit smaller). And for the last few weeks, this device has been always on in my living room where my wife and I leave silly messages for each other.

Summary: This project sends and receives text (SMS) messages via an arduino with cellular modem built into a small enclosure with an LCD display and simple control buttons. Full details of the design and build are on

Could also be called "Most expensive pager made in 2016 ever."

Update: People seem to like this project! It has over 10,000 views, and was even featured on Hackster’s Handpicked Projects of the Week.

Friday, November 18, 2016

How to make a cellular-connected garden monitor

Check out this project I made to monitor the soil moisture level of my remote garden plot. Since the garden has no power or internet available, it uses a cellular data connection to send info back to a cloud service, and then that data gets passed to another cloud service for plotting. A great learning experience!

I posted all the details on, a community for hardware makers with lots of interesting projects:

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