Cheap temperature sensors

I have a handful of AcuRite sensors sprinkled throughout my house.

These sensors are $16 today, but I bought mine around 2017 for $12 each at Home Depot.

I know I could cobble together a cheaper temperature sensor:

So for like $10 + solder + a weekend fiddling, you could make a craptastic internet-equipped temperature/humidity sensor.

But I dreaded building it.

Tinkering with electronic doodads is a fun hobby. But I just wanted something cheapish that would work.

And the AcuRites work.

Plus, the AcuRites work forever on a couple AAAs because they eschew power-hungry wifi in favor of squawking data on 433 MHz.

433 MHz, the original IoT protocol

Even though 433.92 MHz sits squarely in the 70cm ham band, tons of electronic junk spews signals on that frequency.

And with a $25 USB dongle and free software, it’s easy to decode messages chirped out by your AcuRite temperature sensors.

So far, this project had been cheap and simple. But the next step, gathering the data into a time-series database, required more fiddling than I’d expected.

Home Assistant, MQTT, Prometheus, and Grafana.

It was a pain to get rtl_433 data into Home Assistant.

Maybe I’m missing something. But I ended up with a more complex system than I wanted:

1. a systemd unit running rtl_433 with syslog output over UDP: rtl_433 -F syslog:127.0.0.1:1433
2. a systemd unit relaying and filtering syslog output to MQTT (based on this upstream example)
3. a systemd timer to restart rtl_433 when it unexpectedly hangs (often)

After endless fiddling, the relay has an uptime measured in months—it’s stable.

From there, pushing data to Home Assistant, exposing it via the Prometheus plugin, and graphing it with Grafana was a breeze.

Given all this work I’m happy to confirm what I’d long suspected: some rooms in my house are hot while others are cold.

⛵ What is a writing raft?

First proposed by Hrvoje Šimić, a writing raft is a club that forces you to write.

The rules are simple:

1. You must publish a blog post by the end of the month.
2. If you do not publish on time, you’re out of the club (for a month).
3. The club is limited to 5 members.

Željko Filipin conceived of our little Junto towards the end of 2020.

Today we have three members: Me, Željko, and Kosta Harlan. And as of December 2022, the three of us have managed to stay on our raft for one. full. year.

In honor of this milestone, we’re all posting about lessons we learned over the past 12 months.

🍎 Lessons from a year of writing

Blogs should be easy to read. In 1997, Jakob Nielsen succinctly summarized “How Users Read on the Web”: “They don’t.” I use short sentences and omit needless words. And I try to make my blogs look easy to read to keep readers moving.

Get to the point. Nobody has time for throat-clearing—start with your point. If you need more details, add them later.

Your unconscious mind is a better writer than you. Writing and publishing on the same day used to be my habit. Now, I let my rough drafts sit for a day. And I often wake up with a better idea, clearer point, or different direction—even if nobody gives me feedback. My unconscious mind was working on my writing the whole time.

The core question is not how you do math but how does the unconscious do it. How is it that it’s demonstrably better at it than you are?

– Cormac McCarthy, “Stella Maris”

Practice in public. It’s the fastest way to improve. Another deal I made with myself this year is that after I publish a post, I must link it somewhere online.

Internet strangers are a fickle crowd, which makes them a great litmus test for your writing. If a post generates nothing but silence—why not tweak it?

Figure out how to say it better and try again. And try to learn something for next time.

Peer pressure is a tool. The writing raft has shown me: I need someone to notice if I skip a month of writing. Writing the first draft is painful. Knowing I have a deadline keeps me moving through the pain.

And conclusions. I’m so bad at conclusions. But I’m working on it ¯\_(ツ)_/¯.

• Kosta’s post: A year of writing club
• Željko’s post: Two years of blog post writing club

Motivation

I like reading.

When I contrast how I feel after I spend an hour doomscrolling Reddit vs an hour spent reading, there’s no comparison—reading always wins. Too much internet can leave me feeling desolate.

Nonfiction continues to be the best way to learn more about myriad topics. And science now touts the benefits of reading fiction.

But there’s so much to read and so little time. Plus, I worried I was losing what I’d already read. So I set goals and built habits to achieve those goals.

What is working well

• My Kindle – I wish an open device existed that was as wonderful as my Kindle. I hate that I love it so much. But it’s a boon to my reading, and the benefits are hard to quibble over:

  • Front-lit, ePaper display so I can read at night without a light and without interfering with my sleep
  • Stores 100s of books
  • Whispersync keeps it synced with audiobooks on Audible
  • Stores highlights in MyClippings.txt—makes it easy to export highlights
  • Stores words you look up in the dictionary in vocab.db—makes it easy to make vocabulary words into Anki flashcards
  • Light enough to drop on your face while reading in bed (this is a big concern for me)

• Reading notes – I highlight quotes I like and save them in Readwise.

  

  This happens automatically for books I read on my Kindle.

  For paper books, I stole my entire process from Cal Newport:

  • Read with a Zebra #2 in hand
  • Highlight interesting passages—underline or bracket or make a mark in the margins
  • For each page where I highlight a passage, I also make a line across the corner of the page
  • Later, I can flip through the book and find all the pages with lines to find my highlights
  • Then I’ll use Readwise’s “Add via photo” feature to add the highlights to the app

  Readwise can automatically export to online notetaking apps like Evernote. But I like to export each book’s notes to markdown and save them for quick ripgrepping and offline reading under ~/Documents/notes/brain.

• Tracking – It’s surprising how much benefit you get from simply writing down the books your read somewhere.

  I used to forget whole books all the time.

  I’ve tracked every book I’ve read since 2016 on this blog. Posting it online may give me a bit of public accountability, but I think a plain text file would net you the same benefits.

What still needs improvement

• Reviewing – I failed to write a review for each book I read this year. I started strong but faltered around book 30.

  I want to improve this next year. Maybe I should finally concede and join a social reading forum—it might help to have some social accountability.

  The anti-corporate, ActivityPub-backed Goodreads alternative BookWyrm could be a cool place.

Goals for 2023

I’m going for fifty books again.

Here are a few of my vague notions for reading in 2023:

• Math – I want to read about math. I’ve got A.N. Whiteheads’s “An Introduction to Mathematics” and Mark C. Chu-Carroll’s Good Math on my list.
• Trees – I read “The Overstory” by Richard Powers in 2020. In an interview with the Guardian in 2019, Powers said he’d read 120 books about trees while he was writing it. I wonder which was the best?
• The Hainish Cycle books – I’m a sucker for Ursula K. Le Guin. The Dispossessed is one of my favorites. I’ve never read any other book in this series. Why not try a few in 2023?
• Lonesome Dove by Larry McMurtry – In 1994, David Foster Wallace taught English 102 at Illinois State. His syllabus survives online. All the required reading is mass-market paperbacks. Lonesome Dove is one of these cheap paperbacks that also happens to have won the 1986 Pulitzer Prize for fiction, so it’s probably an OK read.
• Moar US President biographies – reading a biography of every American president might be a fun project ¯\_(ツ)_/¯