bluetooth

581 Articles

Simple Device Can Freeze Wi-Fi Camera Feeds

November 1, 2025 by 148 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.

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Original E39 Head Unit Modernized

October 28, 2025 by 24 Comments

Although most modern cars have moved to using proprietary components nearly everywhere, especially when it comes to infotainment systems, for a brief moment which peaked in the 90s and 00s most cars shipped with radios that fit in a standard size opening called a DIN slot. If you wanted a new Pioneer or Kenwood stereo it was usually a simple matter to slide the factory radio out and put your choice of aftermarket head unit in its place. [Stefan] has an E39 BMW from this era and wanted to upgrade the factory radio but use the original hardware instead of replacing it.

This isn’t just a simple stereo upgrade either. [Stefan] has gone all-out for this build which he started in 2020. Beginning with a Kotlin/Jetpack Compose Linux application to handle control input from the vehicle’s various knobs and buttons he moved on to a map application and an on-screen keyboard. From there he implemented VGA to send video to the OEM screen, and now has a fully functional system based on a Raspberry Pi. It does everything the original unit can do including playing music and showing the feed from the backup camera, plus adds plenty of new, modern features like Bluetooth.

For a certain classic car enthusiast, this build hits a sweet spot of modernizing a true classic like the E39 without removing or permanently modifying any OEM components. The amount of work that went into it is pretty staggering as well, with [Stephan] putting in over 100 hours of work just to get the video signal timing correct. We also like it because it reminds us of the flash-in-the-pan “carputer” trend from the late 00s where people in the pre-smartphone age were shoving all kinds of computing horsepower in their trunks.

A photo of the robot and the controller

A Simple $25 Robot Based On The ESP32

October 25, 2025 by 16 Comments

[Paul McCabe] wrote in to let us know about his $25 robot. This small wheeled robot is based on an ESP32 and made using cardboard and hot glue.

You drive the contraption using a Bluetooth game controller thanks to the Bluepad32 library, which boasts a long list of supported hardware. [Paul] provides a Bill of Materials (BoM), complete with current component pricing. We don’t know about you, but it struck us as funny that the microcontroller is less expensive than the battery! Ah, the times we live in. Also [Paul] assumes you already have an appropriate Bluetooth controller and doesn’t include that in the total cost.

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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!

Bluetooth Earrings Pump Out The Tunes

September 27, 2025 by 14 Comments

When you think of a Bluetooth speaker, you’re probably picturing a roughly lunchbox-sized device that pumps out some decent volume for annoying fellow beachgoers, hikers, or public transport users. [Matt Frequencies] has developed something in an altogether different form factor—tiny Bluetooth speakers you can dangle from your earlobes! They’re called Earrays, and they’re awesome.

The build started with [Matt] harvesting circuit boards from a pair of off-the-shelf Bluetooth earbuds. These are tiny, and perfect for picking up a digital audio stream from a smartphone or other device, but they don’t have the grunt to drive powerful speakers. Thus, [Matt] hooked them up to a small Adafruit PAM8302A amplifier board, enabling them to drive some larger speaker drivers that you can actually hear from a distance. These were then installed in little 3D printed housings that are like a tiny version of the speaker arrays you might see hanging from the rigging at a major dance festival. Throw on a little earring hook, and you’ve got a pair of wearable Bluetooth speakers that are both functional, fashionable, and very audible!

[Matt] has continued to develop the project, even designing a matching pendant and a charging base to make them practical to use beyond a proof-of concept. Despite the weight of the included electronics, they’re perfectly wearable, as demonstrated by [DJ Kaizo Trap] modelling the hardware in the images seen here.

We’ve seen plenty of great LED earrings over the years, but very few jewelry projects in the audio space thus far. Perhaps that will change in future—if you pursue such goals, let us know!

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!

The Android Linux Commander

September 9, 2025 by 7 Comments

Last time, I described how to write a simple Android app and get it talking to your code on Linux. So, of course, we need an example. Since I’ve been on something of a macropad kick lately, I decided to write a toolkit for building your own macropad using App Inventor and any sort of Linux tools you like.

I mentioned there is a server. I wrote some very basic code to exchange data with the Android device on the Linux side. The protocol is simple:

  • All messages to the ordinary Linux start with >
  • All messages to the Android device start with <
  • All messages end with a carriage return

Security

You can build the server so that it can execute arbitrary commands. Since some people will doubtlessly be upset about that, the server can also have a restrictive set of numbered commands. You can also allow those commands to take arguments or disallow them, but you have to rebuild the server with your options set.

There is a handshake at the start of communications where Android sends “>.” and the server responds “<.” to allow synchronization and any resetting to occur. Sending “>#x” runs a numbered command (where x is an integer) which could have arguments like “>#20~/todo.txt” for example, or, with no arguments, “>#20” if you just want to run the command.

If the server allows it, you can also just send an entire command line using “>>” as in: “>>vi ~/todo.txt” to start a vi session.

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