wifi

470 Articles

The AirPort Express Still Works In 2025 Thanks To Apple’s Ongoing Support

November 24, 2025 by 4 Comments

Apple was all-in on WiFi from the beginning, launching the AirPort line of products to much fanfare in 1999. In 2004, along came the AirPort Express—a fully-functional router the size of a laptop charger, that offered audio streaming to boot. As [schvabek] found out that while a lot of older Apple gear has long ago been deprecated, the AirPort Express is still very much supported and functional to this day!

Generally, you wouldn’t expect to plug in a 20-year-old Apple accessory and have it work with the company’s modern hardware. However, upon slotting the AirPort Express into a wall socket and starting the initialization process, [schvabek] noted that it was detected perfectly well by his post-2020 Macs. Only, there was a small problem—the configuration process would always stall out before completion.

Thankfully, there was a simple remedy. [schvabek] found that he could connect to the AirPort Express with his classic white plastic MacBook and complete the process. From there, he was astonished that Apple’s servers let him pull down a firmware update for a device from 2004. After that upgrade, the AirPort Express was fully functional with all his modern Apple gear. He could readily stream audio from his iPhone and MacBooks with no compatibility issues whatsoever.

It’s nice to see Apple still supporting this ancient hardware to this day. It’s a nice contrast when companies like Sonos are more than happy to brick thousands of old devices just for the sake of progress. Continue reading “The AirPort Express Still Works In 2025 Thanks To Apple’s Ongoing Support” →

Simple Device Can Freeze Wi-Fi Camera Feeds

November 1, 2025 by 149 Comments

Wi-Fi cameras are everywhere these days, with wireless networking making surveillance systems easier to deploy than ever. [CiferTech] has been recently developing the RF Clown—a tool that can block transmissions from these cameras at some range.

The build is based around an ESP32, with three tactile switches and an OLED display for the user interface. The microcontroller is hooked up to a trio of GT—24 Mini radio modules, which feed a bank of antennas on top of the device. Depending on the mode the device is set to, it will command these modules to jam Bluetooth, BLE, or Wi-Fi traffic in the area with relatively crude transmissions.

The use of multiple radio modules isn’t particularly sophisticated—it just makes it easier to put out more signal on more bands at the same time, flooding the zone and making it less likely legitimate transmissions will get through. Specifically, [CiferTech] demonstrates the use case of taking out a Wi-Fi camera—with the device switched on, the video feed freezes because packets from the camera simply stop making it through.

It’s perhaps impolite to interfere with the operation of somebody else’s cameras, so keep that in mind before you pursue a project like this one. Files are on GitHub for the curious. Video after the break.

Continue reading “Simple Device Can Freeze Wi-Fi Camera Feeds” →

Making WiFi Sound Like Dial-Up Internet

October 24, 2025 by 24 Comments

Dial-up modems had a distinctive sound when connecting, with the glittering, screeching song becoming a familiar melody to those jumping online in the early days of the Internet. Modern digital connections don’t really have an analog to this, by virtue of being entirely digital. And yet, [Nick Bild] decided to make WiFi audible in a pleasing tribute to the modems of yore.

The reason you could hear your dial-up modem is because it was actually communicating in audio over old-fashioned telephone lines. The initialization process happened at a low enough speed that you could hear individual sections of the handshake that sounded quite unique. Ultimately, though, once a connection was established at higher speed, particularly 33.6 k or 56 k, the sound of transmission became hard to discern from static.

Modern communication methods like Ethernet, DSL, and WiFi all occur purely digitally — and in frequencies far above the audible range. Thus, you can’t really “listen” to a Wi-Fi signal any more than you can listen to the rays of light beaming out from the sun. However, [Nick] found an anachronistic way to make a sound out of WiFi signals that sounds vaguely reminiscent of old-school modems. He used a Raspberry Pi 3 equipped with a WiFi adapter, which sniffs network traffic, honing in on data going to one computer. The packet data is then sent to an Adafruit QT Py microcontroller, which uses the data to vary the amplitude of a sound wave that’s then fed to a speaker through a digital-to-analog converter. [Nick] notes this mostly just sounds like static, so he adds some adjustments to the amplitude and frequency to make it more reminiscent of old modem sounds, but it’s all still driven by the WiFi data itself.

It’s basically WiFi driven synthesis, rather than listening to WiFi itself, but it’s a fun reference to the past. We’ve talked a lot about dial-up of late; from the advanced technology that made 56 k possible, to the downfall of AOL’s long-lived service. Video after the break.

Continue reading “Making WiFi Sound Like Dial-Up Internet” →

Smart Bulbs Are Turning Into Motion Sensors

October 7, 2025 by 33 Comments

If you’ve got an existing smart home rig, motion sensors can be a useful addition to your setup. You can use them for all kinds of things, from turning on lights when you enter a room, to shutting off HVAC systems when an area is unoccupied. Typically, you’d add dedicated motion sensors to your smart home to achieve this. But what if your existing smart light bulbs could act as the motion sensors instead?

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Hackaday Links: October 5, 2025

October 5, 2025 by 15 Comments

What the Flock? It’s probably just some quirk of The Almighty Algorithm, but ever since we featured a story on Flock’s crime-fighting drones last week, we’ve been flooded with other stories about the company, some of which aren’t very flattering. The first thing that we were pushed was this handy interactive map of the company’s network of automatic license plate readers. We had no idea how extensive the network was, and while our location is relatively free from these devices, at least ones operated on behalf of state, county, or local law enforcement, we did learn to our dismay that our local Lowe’s saw fit to install three of these cameras on the entrances to their parking lot. Not wishing to have our coming and goings documented, we’ll be taking our home improvement dollars elsewhere for now.

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Heart Rate Measurement Via WiFi, The DIY Way

September 23, 2025 by 13 Comments

A few weeks back, we reported on a research group that figured out how to measure heartrate using perturbations in WiFi signals. [Nick Bild] was interested in this so-called “Pulse-Fi” technique, but noted the paper explaining it was behind a paywall. Thus, he worked to recreate the technology himself so he could publish the results openly for anyone eager to learn.

[Nick] paid for the research paper, and noted that it was short on a few of the finer details and didn’t come with any code or data from the original research team. He thus was left to figure out the finer details of how to measure heart rate via WiFi in his own way, though he believes his method is quite close to the original work.

The basic concept is simple enough. One ESP32 is set up to transmit a stream of Channel State Information packets to another ESP32, with a person standing in between. As the person’s heart beats, it changes the way the radio waves propagate from the transmitting unit to the receiver. These changes can be read from the packets, and processed to estimate the person’s heart rate. [Nick] explains the various data-massaging steps involved to go from this raw radio data to a usable heart rate readout.

It’s a great effort from [Nick] to recreate this research all on his own in his home lab. Files are on GitHub for the curious. If you’re eager to learn more about these innovative measurement techniques, you might like to read our prior reporting on the tech. Also, it’s worth remembering—don’t use your homebrew prototypes for any serious healthcare purposes. Continue reading “Heart Rate Measurement Via WiFi, The DIY Way” →

Heart Rate Monitoring Via WiFi

September 5, 2025 by 22 Comments

Before you decide to click away, thinking we’re talking about some heart rate monitor that connects to a display using WiFi, wait! Pulse-Fi is a system that monitors heart rate using the WiFi signal itself as a measuring device. No sensor, no wires, and it works on people up to ten feet away.

Researchers at UC Santa Cruz, including a visiting high school student researcher, put together a proof of concept. Apparently, your heart rate can modify WiFi channel state information. By measuring actual heart rate and the variations in the WiFi signal, the team was able to fit data to allow for accurate heart rate prediction.

The primary device used was an ESP32, although the more expensive Raspberry Pi performed the same trick using data generated in Brazil. The Pi appeared to work better, but it is also more expensive. However, that implies that different WiFi chipsets probably need unique training, which, we suppose, makes sense.

Like you, we’ve got a lot of questions about this one — including how repeatable this is in a real-world environment. But it does make you wonder what we could use WiFi permutations to detect. Or other ubiquitous RF signals like Bluetooth.

No need for a clunky wristband. If you could sense enough things like this, maybe you could come up with a wireless polygraph.