wifi – MakerBlock

WHY IS EVERYTHING BROKEN?!

The running joke / perennial axiom of hardware startups is “hardware is hard.” I’m not even dealing with any kind of wild hardware. I’m using off-the-shelf sensors and an off-the-shelf board, connecting these in a way I can prove works, and transmitting data back to my PC. For some reason the XIAO ESP32C3 board is just not transmitting data back to the PC. Sure, sometimes I have to restart it which is no big deal. We all need a break. But, now it’s just not resetting properly when I power cycle it.

Anyhow, it’s clearly going haywire:

The good news is that the sensor data coming in from the single microcontroller + three hardwired sensors seems very consistent to the data that’s coming in from the three microcontrollers + single sensors, both over the last day and when compared against readings over the last week.

The observed trends is basically:

Outside temperature dips overnight, with a low around 5-6 AM, peak heat at around 3-4 PM.
When there’s no cloud cover, the house temperature at the entryway bumps first, then the family room, then the ambient house temperature peaks about two hours after entryway bump.
The house and outside temperatures are about the same by 10 PM to 12 AM.

In an ideal world, I’d just restart all the readings right now using the new system, get the sunscreen, then compare these patterns. However, the science display is due in about 10 days, which means I don’t have a lot of time to keep restarting / pivoting.

I guess what I’m doing now is just looking at the baselines. From there, I’ll make a prediction about what would happen with a sunscreen. Some of this sunscreen stuff may depend on external factors – the availability of the sunscreen vendors to measure/make the sunscreen. I don’t know what their lead times are, but I imagine during this heatwave they might be extra busy. Otherwise, I might try to make some predictions about how else we can affect the house temperature and humidity, perhaps with timing the opening windows, opening/closing blinds, and use of the whole house fan.

On interesting aspect of the more distributed Wemos boards / sensors is that these three sensors are also at different heights. The entryway sensor is at floor level in the path of the sun, the family room sensor is at about 6 feet off the ground, and the ambient sensor is at about 13-15 feet in the air. I am expecting the ground level to spike first, then the other two. I’m not sure if I should expect the 6 foot sensor to react first, because it’s closer to the ground height or the 13 foot sensor because it’s closer to the ceiling where the hot air will be collecting. If I had to guess, I would guess the higher one.

Although today is a real scorcher, the one upside is that I can compare it pretty nicely against the data from a very warm day last week with almost no cloud cover.

Summer Science - Testing Effects of Window Coverings on Interior Temperatures

Repeatedly Redundant (Sensing Sensors)

This is the second time the XIAO board stopped working for an extended period of time. Rebooting the board, unplugging/plugging the power cable and adapter from the wall, and even pulling the board from the headers, didn’t work to get it back online. I finally pulled the board, plugged it into USB, then made a do-nothing change to the main.py file¹ and plugged it back into the headers, which worked perfectly. There were no obvious errors in the board – it just … needed a boring update to the code?

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Anyhow, I’d discussed some of the pros and cons of running three Wemos D1 Mini powered sensors² versus just one XIAO ESP32C3 powered sensors – but didn’t think about what happens when a single one goes down. Although the XIAO was out of commission, the three Wemos board kept going so I didn’t really lose any temperature data – especially since the data was so flat during from 12:30 AM to 9 AM this morning.

Admittedly, the locations for the three sensors aren’t perfectly matched. I have the three XIAO thermistors taped to the entryway flooring, taped to the metal plate just inside the family room, and one dangling in the air above the entryway out of any direct sunlight. The three Wemos AHT10’s are on the entryway floor near the entrance to the family room, well inside the family room on the mantleplace, and the last at the top of the stairs with the sensor in open air at almost the exact same height and area as the original XIAO ambient sensor. I actually wanted the second XIAO sensor over on the mantleplace as well – but didn’t want a run wires across the house that far to do it. I’m at peace with getting different readings from these sensors versus my historical readings because:

The AHT10’s are supposed to be more accurate – and also measure humidity which I’ll use near my 3D printer later on
There’s no really good way to tape the AHT10’s to a surface and that doesn’t really tell me much about the “feeling” of warmth inside the house anyhow
The floor readings were constrained by the amount of wire I had rather than really wanting measurements at those specific locations

Just looking at the charts of the incoming data suggests that the AHT10 sensor data is definitely less noisy than the thermistor data. Then again, it might be due to the way in which I’m taking readings every minute but then broadcasting the data every 5 minutes. I’m sure no one would notice or care if I sampled the data every 5 minutes, but when the peak heating coming in from that one picture window only lasts about 30 minutes, I think I’d like to get a better sense of what’s going on minute-by-minute rather than at 5 minute intervals.

Summer Science - Testing Effects of Window Coverings on Interior Temperatures

Changing something behind the comment line from “#==================” to the same thing with one less equal sign [↩]
Way more than triple the soldering [↩]

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

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. [↩]
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. [↩]

Readings so far… 07/11/2026

Here are the readings so far from 07/07/2026 to today 07/11/2026.

There will be a few momentary blips in the data because now and then I have to restart my PC for some stupid reasons. In an ideal world, I’d have a dedicated Raspberry Pi (or even a special computer) designed to specifically capture this data. But, time constraints mean that I’m doing the best I can with what I have. I ordered some AHT10 boards to connect to the Wemos W600 boards (since this board doesn’t have an analog input) I have lying around – only to discover that the Wemos W600 boards are basically abandoned/unsupported and just won’t detect anything coming out of those sensor boards. I then tried some Wemos D1 Mini boards… and no dice there either.

I think the lesson might be… Just get more of the boards that I know will work. These days, that means the Adafruit QtPy boards and the SeeedStudio XIAO ESP32 line. They’re small and at $5-$8, I’ll save WAY more time than if I was trying to get a $2 board working. I guess it could be that the sensor boards are junk – but I won’t really know until I dig into these deeper and that’s not going to happen until the weekend.

I was inspired to start testing this stuff by a local science fair put on by our local utility company. But, let’s not kid ourselves, I’m only too happy to dive into a project like this. Rather than having a bunch of wires from one single ESP32 board going to three different locations in the house, I’d like to ideally have three remote sensors that are battery operated and I could place throughout the house. In a move that may well bite me in the backside, I’m trying to use a Wemos D1 Mini for these remote sensors. I already have them lying around, can run Micropython, and can connect to the I2C / AHT10 sensors I purchased. Rather than scrapping the existing system, I’m going to see if I can build up the new system in parallel, get it running, then disconnect the old system.

While I’ve shopped around for some window screens, I haven’t actually purchased one yet. However, I still have about 2 weeks to go before the science fair, so hopefully I still have time to get this done. :)

Summer Science - Testing Effects of Window Coverings on Interior Temperatures

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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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.
Correct Board Manager URL for ESP boards
An overwhelming amount of information for ESP boards
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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Another tutorial here and here [↩]
Solder in headers, connect via USB, drop in breadboard, prototype away [↩]
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. [↩]