Wireless Hacks

1048 Articles

Mechanical Keyboard Goes BLE

September 14, 2015 by 18 Comments

Like many programmers, [Daniel Nugent] loves his old mechanical keyboard (a WASD Code Keyboard). What he didn’t love was the cord. Sure, you can get a modern wireless keyboard, but it won’t be the same as the keyboard you’ve spent so much time with. Armed with a Bluetooth Low Energy (BLE) module, a rechargeable battery and some coding, he kept his keyboard but got rid of the wires.

Although he has some specific handling for the WASD, the code would very likely handle any PS/2 keyboard. The PS/2 interface is a simple synchronous serial port with a single clock and single data line. Handling it with a microcontroller isn’t very difficult.

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Arduino Masters Ham Radio Digital Mode

September 13, 2015 by 26 Comments

[jmilldrum] really gets a lot of use out of his Si5351A breakout board. He’s a ham [NT7S], and the Si5351A can generate multiple square waves ranging from 8 kHz to 160 MHz, so it only stands to reason that it is going to be a useful tool for any RF hacker. His most recent exploit is to use the I2C-controllable chip to implement a Fast Simple QSO (FSQ) beacon with an Arduino.

FSQ is a relatively new digital mode that uses a form of low rate FSK to send text and images in a way that is robust under difficult RF propagation. There are 32 different tones used for symbols so common characters only require a single tone. No character takes more than two tones.

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Homebrew Mini-Chumby Blends 3D Printing, ESP8266 And A Touchscreen

September 11, 2015 by 5 Comments

We were all despondent when our Chumby’s went dead. And plans to hack at least one of them died when the device quit powering on. [Spiros Papadimitriou] must have missed his too because he’s made a good start at making his own wireless, touchscreen, smart clock.

In all honesty, it isn’t much of a Chumby replacement yet. It has a clock and can control some devices. There’s some hooks to add a weather display that isn’t finished yet. Still, it is a working first step. Of course, anyone can take a Raspberry Pi (or similar), a Wifi dongle, and a touchscreen and do the same thing, right? Maybe, but it is a lot harder to make one you (or your significant other) wants on your nightstand. [Spiros] took a lot of time to design a beautiful 3D printed case.

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Steal This Ham Radio (Technology)

September 9, 2015 by 35 Comments

Although I see a lot of wireless projects, I’m always surprised at the lack of diversity in the radio portions of them. I’m a ham radio operator (WD5GNR; I was licensed in 1977) and hams use a variety of radio techniques. If you think hams just use Morse code and voice communications, you are thinking of your grandfather’s ham radio. Modern hams have gone digital and communicate via satellites, video, and many different digital techniques that could easily have applicability to different wireless projects.

Of course, Morse code may have been one of the first digital modes. But hams have used teletype, FAX, and other digital modes for years. Now with PCs and soundcards in common use, hams have been on the forefront of devising sophisticated digital radio techniques.

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Hams Talk Digital

September 6, 2015 by 45 Comments

Morse code qualifies as a digital mode, although organic brains are somewhat better at copying it than electronic ones. Ham radio operators that did “phone” (ham-talk for voice) started out with AM modulation. Sometime after World War II, there was widespread adoption of single side band or SSB. SSB takes up less bandwidth and is more reliable than AM modulation. On the digital side, hams turned to different and more sophisticated digital transmission types with computers pushing bandwidth down and reliability up. However, a recent trend has been to encode voice over ham radio–sort of VoIP with radio instead of Ethernet–using an open source program called freedv.

[AA6E] made a very informative video where he carries on a QSO (a conversation) with a distant station using freedv. What makes it interesting, is towards the end when the two stations switch to regular SSB. The difference is dramatic and really points out how even with less bandwidth (roughly 3 kHz for SSB vs 1.25 kHz), the digital mode is superior. The freedv software (available for Windows or Linux) compresses audio to 700-1600 bits per second and spreads it over 16 QPSK signals.

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ESP8266 Web Server Farm

September 5, 2015 by 15 Comments

There seems to be a hacker maxim that whatever gadget you are working with, it would be better to have several of them running together. That might explain the ESP8266 web server farm that [Eldon Brown] has built. Yup, a web server farm made from three of everyone’s favorite WiFi dongle, the humble ESP8266.

Eldon’s server farm is currently serving web pages here, running on three ESP8266 boards. Or it was before this posting reduced it to a smoking ruin (screenshot below just in case). Each module is running a dynamic web page and some clever programming he came up with that makes transferring data over these cheap devices quicker.

His page isn’t anything too fancy but it is impressive considering it is running on about $30 worth of hardware, including the breadboard it is wired into. The page includes dynamically-generated graphics and some back-end stuff. I don’t think that it will replace any LAMP servers anytime soon (the ESP8266 took about 2.6 seconds to generate the page below), but it is an impressive hack. [Eldon] has made the full code of the web server that is running the pages available. So, lets add web server farm to the list of things that this neat little device can handle, next to plant weigher, Bitcoin price tracker, MP3 player and many more…

Thanks to [PuceBaboon] for the tip!

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Crystal Radio: It’s A Match!

September 5, 2015 by 10 Comments

A crystal radio is often a kid’s first introduction to building something electronic. [Billy Cheung] is a crystal radio builder who wants to “make crystal radios as easy to use as regular radios.” He’s built many sets, but his latest is one that not only fits in a matchbox, but uses the matchbox as a variable tuning inductor.

There’s no oatmeal box in this design and just a few components. The matchbox contains some ferrite rods and two different windings. By moving the inner part of the matchbox, you can tune different stations. Although the design calls for two fixed capacitors [Billy] found he had enough self resonance (presumably from stray capacitance) that omitting them didn’t hurt his reception of strong signals.

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