Simple Device Can Freeze Wi-Fi Camera Feeds

November 1, 2025 by Lewin Day 22 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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Live Jam Kit Helps Electronic Musicians Stay In Sync

November 23, 2021 by Lewin Day 2 Comments

Jamming live with synths and drum machines can be fun, but for [Christian], there was a little something missing. He was looking for a way to keep everyone in the group on the beat and rocking out, and decided to build something to help.

The ethos of the build was to put one person ultimately in charge of the mix using Ableton. This stops the volume race, as each musician turns their own volume up and the jam devolves into a noisy mess. Each musician also gets a sync button they can hit if their instrument has drifted out of time. Everyone in the jam also gets their own monitor signal in their headphones, as well as a looper as well.

Individual players in the electronic jam can whip up a cool little loop, and spit it out to the main controller running Ableton using the looper. Then, they can mix up something else in their headphones without disrupting the main mix, before spitting it out as a loop again.

[Christian]’s demo video does a great job of showing how it all works. We particularly like the sync button, which gets rid of the usual frustrations when a sequencer in the jam trips over the tempo signal.

It’s all built with a Teensy, and seems like a great way to organize a jam with a bunch of different synths and drum machines. We’d certainly love to join in the fun.

We’ve seen other fun jam kits too, like this neat networked solution. Video after the break.

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Bolt-On Clog Detection For Your 3D Printer

May 19, 2020 by Tom Nardi 19 Comments

Desktop 3D printing technology has improved by leaps and bounds over the last few years, but they can still be finicky beasts. Part of this is because the consumer-level machines generally don’t offer much in the way of instrumentation. If the filament runs out or the hotend clogs up and stops extruding, the vast majority of printers will keep humming along with nothing to show for it.

Looking to prevent the heartache of a half-finished print, [Elite Worm] has been working on a very clever filament detector that can be retrofitted to your 3D printer with a minimum of fuss. The design, at least in its current form, doesn’t actually interface with the printer beyond latching onto the part cooling fan as a convenient source of DC power. Filament simply passes through it on the way to the extruder, and should it stop moving while the fan is still running (indicating that the machine should be printing), it will sound the alarm.

Inside the handy device is a Digispark ATtiny85 microcontroller, a 128 x 32 I2C OLED display, a buzzer, an LED, and a photoresistor. An ingenious 3D printed mechanism grabs the filament on its way through to the extruder, and uses this movement to alternately block and unblock the path between the LED and photoresistor. If the microcontroller doesn’t see the telltale pulse after a few minutes, it knows that something has gone wrong.

In the video after the break, [Elite Worm] fits the device to his Prusa i3 MK2, but it should work on essentially any 3D printer if you can find a convenient place to mount it. Keep a close eye out during the video for our favorite part of the whole build, using the neck of a latex party balloon to add a little traction to the wheels of the filament sensor. Brilliant.

Incidentally, Prusa tried to tackle jam detection optically on the i3 MK3 but ended up deleting the feature on the subsequent MK3S since the system proved unreliable with some filaments. The official line is that jams are so infrequent with high-quality filament that the printer doesn’t need it, but it does seem like an odd omission when even the cheapest paper printer on the market still beeps at you when things have run afoul.

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