Two "On Air" signs

Automatic On Air Light Prevents Distractions During Online Meetings

Remote working has become so normal that even important meetings are now routinely held online. But for those working from home there’s always the risk of pets or flatmates entering the room right when you’re in a heated argument with your boss or presenting your results to an important client. To overcome this problem, [Hans Scharler] designed a system that lights up a big “ON AIR” sign whenever he’s in an online meeting. Although his cat might still disregard it, any human housemates will now know not to disturb him.

The inside of an "On Air" sign with an ESP32 and an LED strip inside[Hans] built a similar device out of spare parts back in 2020, but completely redesigned it to make a more robust version. The basic idea is simple: the sign is illuminated whenever [Hans]’s webcam is enabled, as he is then presumably in a meeting. A few lines of Python code detect the webcam’s state and send the result to ThingSpeak, an IoT service that can be hooked up to various types of gadgets. In this case, the online service sends a signal to an ESP32 hidden inside the sign to turn on an LED string. Those LEDs consume very little power, so they can be driven directly from one of the ESP32’s GPIO ports.

The whole system is powered by a 5V USB power supply and can be placed on a shelf or mounted on a wall, giving your room a bit of a vintage radio studio vibe. Modern IoT services make this kind of project much easier than before: back in 2011, [Matt] probably had to write a lot more code to make a similar Arduino-powered light work.

NTC Thermistor To ThingSpeak Meter Makes A Great IoT Starter Project

There are a lot of IoT solutions and frameworks out there, and [Davide] demonstrates how to make a simple data logging and tracking application with his ESP8266-to-ThingSpeak project, which reads up to four NTC (negative temperature coefficient) thermistors and sends the data to ThinkSpeak over WiFi.

IoT can be a pretty deep rabbit hole, so if you’re looking for a simple project to demonstrate the working parts and provide a starting point, the project’s GitHub repository might help you get started. We’ve also seen ThingSpeak used to track toilet paper sheet usage, which is a nice demonstration of how to interface to a physical object with moving parts.

On the other hand, if you find reading NTC thermistors to be the more interesting part, you’re in luck because [Davide] has more information about that along with a modified ESP8266 Arduino library. Watch a tour of his temperature logging hardware in action in the video, embedded below.

Continue reading “NTC Thermistor To ThingSpeak Meter Makes A Great IoT Starter Project”

IoT toilet paper sheet counter

Keep Track Of Toilet Paper Usage With This IoT Roll Holder

Remember the Great Toilet Paper Crisis of 2020? We sure do, and it looks like our old friend [Vije Miller] does as well, while seemingly harboring a somewhat morbid fascination about how much paper every bathroom visitor is consuming. And to that end, we present his IoT toilet sheet tracker.

His 3D printed roll holder has a Hall effect sensor that counts revolutions of the roll and sends it to a NodeMCU. The number of sheets per roll is entered when the roll is changed, so some simple math yields the number of sheets each yank consumes. Or at least a decent estimate — [Vije] admits that there’s some rounding necessary. The best part of the build is the connection to Thingspeak, where sheet usage is plotted and displayed. Go ahead and check it out if you dare; at the time of writing, there was an alarming spike in sheet usage — a sudden need for 68 sheets where the baseline usage is in single digits. We shudder to think what might have precipitated that. The video below is — well, let’s just say there’s a video.

This isn’t the first time we’ve seen bathroom-based projects from [Vije Miller]. A few years back there was an attempt to freshen the air with plasma, and his IoT shower valve controller probably never scalded anyone accidentally.

Continue reading “Keep Track Of Toilet Paper Usage With This IoT Roll Holder”

An Electronic Love Letter To The Wind

Home weather stations are a great way for hackers and makers to put their skills to practical use. After all, who wants to hear the current conditions for the whole city when they could setup their own station which drills that information down to their very own street? Such a setup doesn’t need to be any more complex than a temperature sensor wired up to a microcontroller, but then not all of us are quite the weather fanatic that [Richard] clearly is.

The system he’s built to monitor the wind over his home is, to put it mildly, incredible. We might not all share the obsession [Richard] apparently has with the wind, but we can certainly respect the thought and design that went into this comprehensive system. From his scratch built anemometer to the various ways he’s come up with to display the collected environmental data throughout his home, if this build doesn’t inspire you to hack together your own weather station then nothing will.

At the heart of the system is the anemometer itself, which makes use of several scavenged parts such as the bottom halves of plastic Easter eggs as wind cups. The cups spin on a short length of M5 threaded rod inside of a 635ZZ bearing, which ultimately rotates a “light chopper” placed between a red LED and a OPL550A optical sensor. In a particularly nice touch, [Richard] has even included a few power resistors arranged around the moving parts to use as a heater which keeps the device from freezing up when the temperature drops. The sensor creates eight digital pulses per revolution, and feeds data into the base station though a 30 meter (98 feet) cable.

From there, the base station uses an ESP8266 to upload wind and temperature data to ThingSpeak and Weather Underground to be viewed through their respective web interfaces and applications. The project really could have ended here and still been impressive in its own right, but the station also includes 433 MHz and NRF24L01 transmitters to send the data to the other display devices which [Richard] has designed.

The 433 MHZ display is built into the frame of a lantern, and shows the current time and temperature on an LED readout as well as historical wind and temperature graphs on a 2.2 inch ILI9341 TFT screen which [Richard] has rotated into a portrait layout. There’s a red light on top that blinks whenever a signal is received to show that the system is working, and even a touch sensor which can be used to turn off the TFT screen at a tap if you’re not interested in seeing the full charts.

The other display, which [Richard] calls the “picture frame” utilizes a dizzying array of single LEDs, a handful of digital LED readouts, and even an OLED screen for good measure. They all work together to show the current wind speed as well the averages for the past day in three hour segments. As this display features a real time display of current wind conditions and averages for as short a period of two minutes, it uses the NRF24L01 receiver to get data from the base station at a rate of 3 Hz.

In the past we’ve seen 3D printed weather stations, and of course some pretty simple affairs using little more than an ESP8266 board and some sensors. But few have ever put so much thought into how to present the collected data to the user. If you’re serious about knowing what it’s like outside the confines of your bunker, [Richard] has got some tricks to show you.

Continue reading “An Electronic Love Letter To The Wind”

Welcome To The Internet Of Hamsters

It was only a matter of time. Everything else is getting its data logged and reported to the Internet for detailed analysis, so why should our rodents be any different? The cover story is that [Nicole Horward] hooked her pet hamster Harold up to the web because she wanted to see if he was getting as much exercise as he should. The real reason is, of course, that Harold wanted to show off to his “friends” on Hamsterbook.

The hardware side of this hack is very simple, a magnetic door sensor (like the kind used in alarm systems) is used to detect each time the wheel makes a complete rotation. The sensor is hooked up to the GPIO pins of a Raspberry Pi, where it’s read by a Python script. A small LCD screen was added to give some visual feedback on Harold’s daily activity, and the whole thing was boxed up in a laser cut enclosure.

That gave [Nicole] a cute little display next to Harold’s cage, but it didn’t do much for analyzing his activity. For that, a script is used to upload the data every minute to a ThingSpeak channel via MQTT. This automatically generates attractive graphs from the raw data, making it much easier to visualize what’s happening over the long term.

Now might be a good time to brush up on your MQTT knowledge, so that your pet could be the next to join the IoT revolution.

Continue reading “Welcome To The Internet Of Hamsters”

Review: IoT Data Logging Services With MQTT

For the last few months, I had been using Sparkfun’s Phant server as a data logger for a small science project. Unfortunately, they’ve had some serious technical issues and have discontinued the service. Phant was good while it lasted: it was easy to use, free, and allowed me to download the data in a CSV format. It shared data with, which at the time was a good solution for data visualization.

While I could continue using Phant since it is an open-source project and Sparkfun kindly releases the source code for the server on Github, I thought it might be better to do some research, see what’s out there. I decided to write a minimal implementation for each platform as an interesting way to get a feel for each. To that end, I connected a DHT11 temperature/humidity sensor to a NodeMCU board to act as a simple data source.

Continue reading “Review: IoT Data Logging Services With MQTT”

Your Internet Of Things Speaks Volumes About You

If only Marv and Harry were burglars today; they might have found it much easier to case houses and — perhaps — would know which houses were occupied by technically inclined kids by capitalizing on the potential  vulnerability that [Luc Volders] has noticed on ThingSpeak.

As an IoT service, ThingSpeak takes data from an ESP-8266, graphs it, and publicly displays the data. Some of you may already see where this is going. While [Volders] was using the service for testing, he realized anyone could check the temperature of his man-cave — thereby inferring when the house was vacant since the location data also happened to be public. A little sleuthing uncovered several other channels with temperature data or otherwise tied to a location that those with nefarious intent could abuse.

Continue reading “Your Internet Of Things Speaks Volumes About You”