Tag: wemos d1

Now with remote sensors

As with many of my projects, the scope and build has changed somewhat over time.  This project started with me just taking readings around my house with an infrared thermometer at somewhat regular intervals.  However, this was tedious and prone to variance as I measure things by hand.  After that, I started using a single XIAO board with three hardwired thermistors around our entry way.  The nice thing about this kind of a setup is that I really only have to build/program one board, set it up, and then let it send data to my PC.  The downside is that there’s wires everywhere – and it used up my entire stash of glorious rainbow colored ribbon cable. 1

Practice when I work on a project is to buy replacement parts for the pieces I use up after I’m done.  This way, I will still have stuff on hand for my next project.  So, I’ll need to pick up more colored colored ribbon cables, small solderable prototyping boards, and replacement microcontrollers.  Back in the day, I would stock up on Adafruit Trinkets, but for about a lower price and a slightly larger footprint, I can get a XIAO board with more IO ports, memory, speed, and built-in wifi/bluetooth.  The little prototyping boards I’d purchased aren’t available from the same seller on Amazon, which is too bad.  I really like these boards because they’re bigger than just the microcontroller, have power rails that run down the center rather than the sides and horizontal rows, and rounded corners.  They’ve been incredibly convenient.

With this project, I wired up three Wemos D1 Mini boards, each to a different AHT10 temperature/humidity sensors, and shoved them into my favorite enclosure – cheap tap lights.2

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As I’ve mentioned previously, I’m just not very good at soldering – which is why I go very slowly, checking, rechecking my progress as I go.  Even so, I made two small and fixable mistakes, soldering the wrong connection somewhere and later accidentally bridging two contacts.  Fortunately, some things are fixable.

The construction of these little wifi sensors isn’t very interesting.  Rather than run each board off of 4.5 volts from three AA batteries, I’m using 3.0 volts from two AA batteries.  By not passing that 4.5 volts through the voltage regulator to bring the power down to 3.3 volts, I should be able to save enough battery life to justify running this system off 2/3 the batteries.  This meant I soldered the power connectors to the end and middle battery connectors.  I have a suspicion that the XIAO boards are probably more power efficient, but if I don’t use those Wemos boards for something simple like this, well, I’ll probably never get around to doing it.

In any case, I now have these three sensors throughout the house near the locations of the prior sensors.  I like these AHT10 sensors – but unlike the thermistors, I can’t really get the sensor right up against a surface.  Hopefully it won’t matter much.  While the readings directly off the flooring and metal plate were dramatic and gave a sense of the heat that was being absorbed and released by the house, it’s the actual temperatures in the house that are what I’m after.  In the meantime, I’m running both systems in parallel so I can make sure they’re both pulling in reasonably consistent readings.  If so, I’ll pull down the tangle of wires, wind them up, and set them aside for the next project.

Summer Science - Testing Effects of Window Coverings on Interior Temperatures
  1. Testing the Effect of Interior and Exterior Window Coverings on Interior Temperatures
  2. Testing Interior Temperatures – preliminary results
  3. Readings so far… 07/11/2026
  4. Now with remote sensors
  5. Repeatedly Redundant (Sensing Sensors)
  6. WHY IS EVERYTHING BROKEN?!
  7. Musings on measurements and a wacky cat
  8. WWMWD?
  9. Back on track
  10. House Temperature Readings So Far
  1. I picked up 15 feet for $5 about 13 years ago from Sparkfun, now selling for $7.  Digikey also carries it for quite a bit more, but I haven’t run the math to figure out whether shipping makes a difference. [↩]
  2. With some hunting, you can find a set of tap lights for about $1, they include a battery holder, switch, bright white LED, attractive sturdy case, and semi-translucent top. [↩]

ESP WiFi Board Experiments

A friend of mine pointed me in the direction of some ESP32 board tutorials over at MsRaynsford.co.uk.1 You know it’s a fast moving area when a post that’s less than a month old already has a dead link.  :)  Rather than re-creating all the tutorials that are already out there, I’m going to just jot down my notes and links as a short of “quick start guide to quick start guides.”

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  1. ESP Boards
    1. There’s several different “flavors” of ESP WiFi tech, however it seems as if they all break down into one of three different categories.
      1. Bare ESP WiFi module.  These require a bit of effort to make work since the bare module requires the pins to be broken out to be made useful.
      2. ESP WiFi breakout boards.  This type of board, which has 8 pins broken out, requires a programmer.  Since these 8 pins are arranged in a 2×4 pattern, they can’t be used directly in a breadboard.
      3. ESP WiFi development boards.  These board seem to have lots of pins broken out and typically a USB connector.  Since these boards have more features (voltage regulators, compatibility with other boards’ form factors, USB communication built-in), they’re going to be more expensive.  There’s the Adafruit Huzzah, the Sparkfun ESP Thing, and then something called the ESP Wemos D1.
    2. There are several different ESP modules and boards which have varying amounts of space from 512kb to 4MB and varying amounts of pins from 2 to 24 pins.  These modules all tend to have different names (ESP-01, ESP-07, etc, etc) but are all known as ESP8266.
    3. The ESP modules require 3.3v, so a 5.0v USB or other source will fry them.  Plan accordingly.  Some development boards have voltage regulators on them to adjust the power going to the module.
  2. Correct Board Manager URL for ESP boards
  3. An overwhelming amount of information for ESP boards
  4. Ordering Boards
    1. I’m ordering several boards off of Aliexpress.  I’m getting a few Wemos D1 boards, since they’ll be easy to prototype with2 , and a few ESP-01 breakout boards and a single programmer to toss into a project.  Then again, at <$3 a piece for the Wemos boards and <$2 a piece for the ESP breakouts, it doesn’t make a ton of sense to stretch to put the ESP-01’s into a project.  My thinking is that most any project I build will only use a pin or two and not be too terribly complicated anyhow, so that once it’s been prototyped I can just burn it into the ESP-01’s and permanently install it into a project.
    2. I’m not exactly sure which what WiFi enabled things I’d like to build yet. 3  Here are some ideas:
      1. A pair of tap lights that are connected over the internet.  I’d tap one before I left work, it would flash a color to let me know it sent a message, and the other one at home would light up to let my fam know I was on the way.  I guess it’s similar in theory to this.
      2. A button to call an Uber or Lyft.
      3. A button that will email or call my cell in 2-5 minutes from the time I press the button.  Useful when I know someone who stepped into my office isn’t good at taking a hint.  Or when I need to get off a conference call.
      4. A button that can be used to log simple events.  Might be useful at work in a variety of ways.
      5. A button that will automatically start a print job on my WiFi enabled 3D printer.
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  1. Another tutorial here and here [↩]
  2. Solder in headers, connect via USB, drop in breadboard, prototype away [↩]
  3. Sometimes I will buy a few parts I know will be useful, spend some time tinkering with them, and then later build something when inspiration strikes. [↩]
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