Posts filed under ‘Uncategorized’

Weather Camera Sunrise on Molly’s Birthday

The weather camera caught a nice sunrise on Molly’s birthday.

[Raspberry Pi 4, Raspberry Pi HQ Camera, 6mm lens]

October 27, 2020 at 12:21 am Leave a comment

Did I Get Punked by Advertising?

I always say advertising doesn’t work on me. Unfortunately, I’m wrong. There are specific instances where advertising seems to work on me:

  1. When I’m watching a sporting event, and a commercial plays for a restaurant I already like, it might work and I’ll order from that place.
  2. Fountain pens – I’ll get email from a purveyor of pens, ink, and paper, from whom I’ve already purchased and had good experiences, saying, “come look at these new products…” Yeah, I’ll sometimes spend money. Lookin’ at you,, and
  3. Electronics-related email, YouTube vids, or Adafruit learning guides and I’ll drop coin for the shiniest new bits – my last indulgence was an I2C PM2.5 particulate matter sensor – oh, yeah.

In following YouTube fountain pen videos in autoplay mode while I do other things, like work on wiring a prototype satellite (I’ll write more about that later), I ran across a young woman (@studyquill) who is unnaturally organized. When she was in high school she wrote a successful book on study habits. As someone who is unnaturally disorganized, I started to pay attention, and eventually subscribed to her channel (in spite of some annoyances).

Hold that thought. They other key piece here is that I have a 2018 iPad Pro 12.9″ (I hear people mumbling, “of course you do”) and I’m exploring ways of using it effectively for taking notes and making drawings (those of you who know me well enough are laughing). I use ProCreate for fumbling artwork and an app called Concepts for note-taking. Concepts is supposed to be a drawing program like ProCreate, but it works for my style of note-taking, which means it supports fast color switching for color-coding my notes, endless canvas, and adjustable splines for drawing and writing. I also got an Apple Pencil, which I always thought was kind of a dumb gimmick until a graphic artist friend said he used the pencil every day and couldn’t work without it. Ok, so I tried it (spoiler: get one).

The one thing that bothers me is the pencil slides on glass like it’s on… well, glass. Very slippery with little tactile feedback. That’s annoying but I thought that’s just what it is.

Here’s the confluence of these random-seeming threads.

I was watching @sutdyquill and she had a sponsored video (here we go – the advertising tie-in) wherein she talked about the slippery-glass problem (which I have). The sponsor was a successful KickStarter project called “PaperLike.” It’s a tactile feedback screen protector for the iPad. Apparently, it provides just enough tip drag to feel like paper, or at least like not-glass. Phil immediately drops coin on for one.

I would say advertising worked.

Since then I’ve seen one negative review, but I have that gut reaction that it was designed to get people to buy a specific alternative product, so I take that with a huge salt-lick of salt.

Whether I got punked by advertising remains to be seen.

October 22, 2020 at 2:28 pm Leave a comment

Finally some organization here.

I’ve spent entirely too much time throwing myself into my job(s) and not enough time curating my own content. I’ve added this blog,, to my domain and will begin writing about things that I either enjoy or feel are important. This means there will be astrophotography that I’ve done, along with more serious topics like failures in cybersecurity risk assessment, or management’s culpability for the dismal state of information security in many (most?) companies. There will also be a fair amount of Maker content.

If you like, drop me a comment to let me know what you’d like to read about.

December 30, 2019 at 9:42 am 1 comment

Comparing Adafruit Gas Sensors

I am comparing the performance of the Adafruit CCS811 and SGP30 gas sensors. These sensors monitor the atmosphere for effective carbon dioxide (eCO2) and total volatile organic compounds (TVOC) and report those values when polled. You can artificially test the sensors by blowing on them and watching the reported values spike.

I wanted to make this comparison because I was running these sensors independently and I noticed occasional spikes or artificially elevated periods. In order to test the sensors and remove actual environmental fluctuations, I needed both sensors connected to the same board.

At first, I used an Arduino Nano, but then switched to an Adafruit ESP32 Feather. For some reason the CCS811 board would report only zeros. I suspect this is because the CCS811 uses I2C clock stretching, and the ESP32 probably doesn’t support that in hardware.

Enter the prototype Metro M4 Express. This is a new pre-production board (which I am helping test) from Adafruit. It runs a custom cross-compiled version of CircuitPython – currently 3.0.0 alpha 1 compiled on 2/27/18. There are CircuitPython modules available in Adafruit’s GitHub repositories for both the CCS811 and SGP30 sensors. It took me almost no time at all to compile the latest firmware for the M4, flash it, and connect the circuit that I used for the ESP32 test. Both sensors work flawlessly.

There is, however, the pesky case of spurious values. On a plot of observations vs. the difference between the readings (i.e., SGP30 – CCS811 values), we should see a flat line indicating the sensor values are moving in lock-step with each other, with perhaps some minor fluctuations. That’s not what we see, though!

As you can see, the SGP30 has quite large spikes that the CCS811 does not. This indicates that the SGP30 values are considerably less reliable than the CCS811, which is unfortunate because I like the electronics in the SGP30 a lot more (true I2C for one). Unfortunately, the numbers don’t lie: the CCS811 is a more reliable gas sensor.

March 1, 2018 at 1:23 pm Leave a comment