wireless

328 Articles

Internal Wireless Headphones

September 28, 2009 by 42 Comments

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Wireless headphones can be a wonderful way to help clear up the clutter inherent in most desktop PC systems. However, after plugging a wall wart in, and the headphone jack into the computer, the number of wires used has actually doubled. After [Parker] found an old set of JVC 900 Mhz wireless headphones (and a generic 900MHz transmitter), he cracked open the case to see what he could do with them. Realizing that the transmitter used a 12V DC source, he powered it with an unused floppy connector (which provides +12V, +5V, and two ground lines). He also wired the audio-in line directly onto his sound card headers rather than feeding out a headphone jack to the back. He then wrapped the whole thing in plastic to prevent unwanted shorting and placed it back in his PC, leaving him with a very functional wireless system. Detailed photos after the break.

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Wireless RGB Light Bulb

September 20, 2009 by 15 Comments

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Want to make the above yourself? [Sprite_tm] did a thorough job documenting the build step by step (complete with pics, schematics, graphs, and links to the parts used). In summary, [Sprite_tm] busted open an Ikea CFL bulb to reuse the housing. Inside, he installed a scavenged power supply, ATtiny44, RGB LED module, and a radio receiver. A remote control allows [Sprite_tm] to change the lighting of his room to nearly any color. The cost of the project is a little under $30. The price tag isn’t so steep when one considers the insanely long lifetime of LEDs.

Harry Potter Marauders Map Realized

September 5, 2009 by 19 Comments

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After reading about cheap wireless for microcontrollers, [Leigh] left a comment about his Marauders map. Much like the Harry Potter version, whoever holds the ‘map’ is able to see the location of the ‘marauders’ within certain bounds. Unlike the magical version however, each person being tracked needs to hold a PICAXE 08M, GPS, and 433.92MHz transmitter: while the map needs a computer running his Python script and a receiver of the same frequency. It has the potential for locating people, but we feel it might be better off in a swarm robotics setup.

Cheap Wireless For Microcontrollers

August 30, 2009 by 44 Comments

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Everybody loves microcontrollers, including the Arduino, allowing you to create whatever you imagine. That is unless you want to hack together something wireless. Originally you had to rely on the expensive XBee protocol or other wireless options, but no longer. Hobby Robotics found an extremely cheap transmitter and receiver and wrote a quick guide for wiring them up to an Arduino. Now your wireless projects can come to life, as long as you are within 500 feet and don’t mind 2400bps; minor trade offs compared to the gains of wireless freedom. Final note: You aren’t limited to Arduino, we would love to see someone modify this to work with a PIC or other microcontroller.

BPSK On 433 MHz European ISM Band

August 3, 2009 by 10 Comments

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[WaveRider] is using a type of phase shift keying called BPSK to transmit digital sound and video for remote telemetry. Though a higher signal to noise ratio (SNR) is generally sought after with communications, legal limitations are imposed on total radiated power. To balance the two headed beast, he opted out on frequency shift keying due to binary shift keying’s ability to work with lower SNR. This adds the difficulty of properly reconstructing the digital signal at the receiver. A PLL based carrier regeneration circuit is used to reconstruct the signal. Using the Rabit2000 processor as the host controller on both transmitter and receiver, 96KB/Sec serial data is obtained. On the other side of the spectrum is the Homemade regenerative tube radio.

Build A Wireless Keylogger

July 17, 2009 by 17 Comments

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Hardware Keylogger solutions has released the plans and files for their wireless logger. It has a range of about 50 yard between the transmitting dongle and the receiver. It is based around an Atmel AT91SAM7S64 and the PCB is pretty tiny. In case you hadn’t noticed yet, they sell them as well. The cool thing about this is that key data is transmitted in real time, allowing you to see it as it happens instead of having to go retreive the log physically like you used to.

Homemade Regenerative Tube Radio

July 13, 2009 by 24 Comments

There are no microcontrollers in this project. In fact you wont find a single transistor. This classic regenerative tube radio, modeled after an early 20th century homebrew is complete with schematic and additional photos. For those who are not familiar with tube designs and for simplicity, the regeneration circuit can be thought of as feedback though this relation may be argued. Read the rest after the break which includes a crash course in tube operation. Continue reading “Homemade Regenerative Tube Radio” →