ESP32

683 Articles

2025 Component Abuse Challenge: Load Cell Anemometer

October 9, 2025 by 22 Comments

When you think anemometer, you probably don’t think “load cell” — but (statistically speaking) you probably don’t live in Hurricane Country, which is hard on wind-speed-measuring-whirligigs. When [BLANCHARD Jordan] got tired of replacing professionally-made meteorological eggbeaters, he decided he needed something without moving parts. Whatever he came up with would probably qualify for the Component Abuse Challenge, but the choice of load cells of all things to measure wind speed? Yeah, that’s not what the manufacturer intended them for.

In retrospect, it’s actually a fairly obvious solution: take a plate of known area, and you’re going to get a specific force at a given air speed. The math isn’t hard, it’s just not how we normally see this particular measurement done. Of course, a single plate would have to be pivoted to face the wind for an accurate reading, which means moving parts– something specifically excluded from the design brief. [Jordan] instead uses a pair of load cells, mounted 90 degrees to one another, for his anemometer. One measures the force in a north-south axis, and the other east-west, allowing him to easily calculate both wind speed and direction. In theory, that is. Unfortunately, he vibe coded the math with ChatGPT, and it looks like it doesn’t track direction all that well. The vibe code runs on an ESP32 is responsible for polling data, tossing outliers, and zeroing out the load cells on the regular.

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Billy Bass Gets New Job As A Voice Assistant

October 9, 2025 by 8 Comments

For those who were alive and conscious before the modern Internet, there were in fact things that went “viral” and became cultural phenomenon for one reason or another. Although they didn’t spread as quickly or become forgotten as fast, things like Beanie Babies or greeting a friend with an exaggerated “Whassup?” could all be considered viral hits of the pre-Internet era.

Another offline hit from the late 90s was the Billy Bass, an absurdist bit of physical comedy in the form of a talking, taxidermied fish. At the time it could only come to life and say a few canned lines, but with the help of modern hardware it can take on a whole new life.

This project comes to us from [Cian] who gutted the fish’s hardware to turn it into a smart voice assistant with some modern components, starting with an ESP32 S3. This chip has enough power to detect custom “wake words” to turn on the fish assistant as well as pass the conversation logic to and from a more powerful computer, handle the audio input and output, and control the fish’s head and tail motors. These motors, as well as the speaker, are the only original components remaining. The new hardware, including an amplifier for the speaker, are mounted on a custom 3D printed backplate.

After some testing and troubleshooting, the augmented Billy was ready to listen for commands and converse with the user in much the same way as an Alexa or other home assistant would. [Cian] built this to work with Home Assistant though, so it’s much more open and easier to recreate for anyone who still has one of these pieces of 90s kitch in a box somewhere.

Perhaps unsurprisingly, these talking fish have been the basis of plenty of hacks over the years since their original release like this one from a few years ago that improves its singing ability or this one from 2005 that brings Linux to one.

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Divining Air Quality With A Cheap Computer Vision Device

October 5, 2025 by 10 Comments

There are all kinds of air quality sensors on the market that rely on all kinds of electro-physical effects to detect gases or contaminants and report them back as a value. [lucascreator] has instead been investigating a method of determining air quality that is closer to divination than measurement—using computer vision and a trained AI model.

The system relies on an Unihiker K10—a microcontroller module based around the ESP32-S3 at heart. The chip is running a lightweight convolutional neural network (CNN) trained on 12,000 images of the sky. These images were sourced from a public dataset; they were taken in India and Nepal, and tagged with the relevant Air Quality Index at the time of capture. [lucascreator] used this data to train their model to look at an image taken with a camera attached to the ESP32 and estimate the air quality index based on what it has seen in that existing dataset.

It might sound like a spurious concept, but it does have some value. [lucascreator] cites studies where video data was used for low-cost air quality estimation—not as a replacement for proper measurement, but as an additional data point that could be sourced from existing surveillance infrastructure. Performance of such models has, in some cases, been remarkably accurate.

[lucascreator] is pragmatic about the limitations of their implementation of this concept, noting that their very compact model didn’t always perform the best in terms of determining actual air quality. The concept may have some value, but implementing it on an ESP32 isn’t so easy if you’re looking for supreme accuracy. We’ve featured some other great air quality projects before, though, if you’re looking for other ways to capture this information. Video after the break.

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Building A Desk Display For Time And Weather Data

October 2, 2025 by 19 Comments

Just about every laptop, desktop, and smartphone in your life can tell you the date, time, and current weather predictions. However, sometimes it’s nice to have simple data displayed on a bespoke device. That’s what inspired [Mario] to create ESPTimeCast. 

As you might have guessed by the name, the project is designed around the ESP32 and ESP8266 microcontrollers; either one is up to the task of running the show here. Both come with Wi-Fi connectivity out of the box, which makes it easy for them to hook up to the Internet to query NTP servers for the time and weather data from OpenWeatherMap. The data is then displayed on an LED matrix display, made up of four 8×8 LED modules and driven with the aid of the MAX7219 IC. Configuration is handled over a simple web interface hosted on the device itself. All the parts are wrapped up in a 3D-printed housing that would be very fitting in any home that appreciates the magic of late 60s/early 70s decor.

Hackers love building clocks, weather stations, and other useful information displays. We’ve seen a great many examples over the years. If you’re cooking up your own neat project in this area, don’t hesitate to let us know!

Hard Hat Becomes Bluetooth Direction Finder

September 30, 2025 by 10 Comments

Have you ever wanted to find a Bluetooth device out in the wild while looking like the comic relief character from a science-fiction series? You might like Dendrite, the direction-finding hat from [SolidStat3].

Dendrite is intended for hunting down Bluetooth devices. It’s capable of direction estimation based on signal strength readings from four ESP32 microcontrollers mounted on an off-the-shelf hard hat. Each ESP32 searches for BLE devices in the immediate area and reports the apparent signal strength to a fifth ESP32, which collates readings from all units. It then runs a simple multilateration algorithm to estimate the direction of the device. This information is then displayed via a ring of addressable LEDs around the perimeter of the hat. White LEDs marking the direction of the detected device. The only problem? You can’t see the LEDs while you’re wearing the hat. You might need a friend to help you… or you can simply take it off to see what it’s doing.

Ultimately, this project is a useful direction-finding hard hat that would also make a perfect prop from an episode of Inspector Spacetime. We’ve covered direction finding in other contexts before, too. Meanwhile, if you’re cooking up your own innovative hard hat (or radio) hacks, don’t hesitate to let us know!

Smart Home Gets A Custom Keypad Controller

September 28, 2025 by 3 Comments

Voice assistants and smartphones are often the go-to interfaces for modern smart home systems. However, if you fancy more direct physical controls, you can go that route as well. To that end, [Salim Benbouziyane] whipped up a nifty keypad to work with his Home Assistant setup.

The build is based on an ESP32 microcontroller, which has wireless hardware onboard to communicate with the rest of [Salim’s] Home Assistant setup. Using the ESPHome firmware framework as a base, the microcontroller is connected to a four-by-three button keypad array, built using nice clicky key switches. There’s also an indicator light on top as a system status indicator. A fingerprint scanner provides an easy way for users to authenticate when disarming the alarm.

Security and speed were the push for [Salim] to whip up this system. He found it difficult to disarm his alarm in a hurry when fumbling with his phone, and the direct keypad entry method was far more desirable.

Sometimes, the easiest route to the smart home of your dreams is to just build the exact solutions you need. Video after the break.

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Bringing Bluetooth To The Zune

September 27, 2025 by 10 Comments

The Zune might have joined the portable media player game too late to ever really be competition for the iPod, but that doesn’t mean it didn’t pick up some devoted fans along the way. Some of them are still breathing new life into the device, such as [The Director of Legal Evil Emeritus] at the Louisville Hackerspace, with this project that gives it Bluetooth capability.

As far as media players go, there’s still some solid reasons to rock a Zune. Compared to other devices of the era, it offers a better DAC, an FM tuner, and no iTunes reliance. The goal of this project was to bring a bit of modern functionality without having to do any modification of the Zune itself. As the player supported docks with IR remotes, this build involves using an ESP32 to listen to the Bluetooth signal coming from the speakers, interpret any button presses, and forward them along to the Zune’s dock.

There is a dedicated scene for these old music players, but this build is unique for not needing to crack open the case and splice in a Bluetooth module. Even then, those typically don’t have the ability to interact with things like this speaker with its integrated control buttons.

We don’t often seen Zune hacks come our way — the last time Microsoft’s player graced these pages was in 2010, when the Open Zune Development Kit was released.

Thanks to [JAC_101] for the tip!