Home screen for Marian, my personal AI librarian.

Making Marian, Your Personal AI Librarian, in 4 Simple Steps

Tired of the lackluster book recommendations you get from GoodReads or Amazon? Suppose you could converse with someone who really know books, who knows your likes and dislikes. You can create your own, personal, custom GPT today to fill this role.

August 14, 2025 · 5 min · Tim Graettinger
Screenshot from my personal LibraryThing account - 17 years of reading history.

Meet Marian: How 11 Questions Evolved Into My Personal AI Librarian

Suppose you could consult with your bookshelves. That’s the idea behind Marian, my personal AI librarian, a custom GPT I built around my preferences and reading history.

July 30, 2025 · 4 min · Tim Graettinger
Time chart of radon levels over a ten-day period along with 3-hour and 24-hour rolling averages.

Collab: Exploring Radon Levels with Data Analyst GPT

I’ve been tracking radon levels in our home for 9 months. Collaborating with Data Analyst GPT to analyze them was actually fun…

July 16, 2025 · 8 min · Tim Graettinger
Two cartoon people sitting on a couch, thinking about what to watch on TV.

Spark Notes: Ten Things I Wanted from Our Netflix Ratings: Prelude to a Custom GPT

Not long ago, I found myself thinking about our old Netflix DVD ratings. I wondered what I could do with them that would be cool…

July 7, 2025 · 4 min · Tim Graettinger
Schematic layout of the Jackery and connected devices across our house.

Lab Notes: Taming the Tangle: Custom Cords for the Outage to Come

A recent power outage exposed a weak link in our emergency setup — not enough usable extension cords. I designed and built a custom set for powering our home from our Jackery. Here’s how I tailored them to our layout.

July 6, 2025 · 2 min · Tim Graettinger
Side-by-side images: initial power outage information (left) and the outage map for our area (right).

Lab Notes: Lessons from a 24-Hour Power Outage

When the power went out this time, we were ready. Sort of…

June 30, 2025 · 3 min · Tim Graettinger
Chart of the number of power outages versus their duration.

It Was a Dark and Stormy Afternoon: How We Used Data to Prepare for Our Next Power Outage

The power went out and stayed out… for three days. How do you prepare for the next time?…

May 25, 2025 · 9 min · Tim Graettinger
Drawing of the well-holding tank-house system that supplies our water

The Day the Water Stopped: What I Learned During a Seven-Month Drought

We lost water to the house. What do you do next when you’re in a drought?…

April 21, 2025 · 7 min · Tim Graettinger
Map of our club members and candidates for a new meeting location

Where Can We Meet? Making an Informed Choice for our Toastmasters Club

Our Toastmasters Club needed a new home. But where?…

March 20, 2025 · 9 min · Tim Graettinger
Graph of our solar production and our energy consumption over time.

Is Our Solar Surplus Big Enough to Drive an EV for Free?

Can our solar system power our house AND an electric vehicle?…

March 3, 2025 · 6 min · Tim Graettinger