Simple Directional WiFi Antenna

Back in 2007, [Stathack] rented an apartment in Thailand. This particular apartment didn’t include any Internet access. It turned out that getting a good connection would cost upwards of $100 per month, and also required a Thai identification card. Not wanting to be locked into a 12-month contract, [Stathack] decided to build himself a directional WiFi antenna to get free WiFi from a shop down the street.

The three main components of this build are a USB WiFi dongle, a baby bottle, and a parabolic Asian mesh wire spoon. The spoon is used as a reflector. The parabolic shape means that it will reflect radio signals to a specific focal point. The goal is to get the USB dongle as close to the focal point as possible. [Stathack] did a little bit of math and used a Cartesian equation to figure out the optimal location.

Once the location was determined, [Stathack] cut a hole in the mesh just big enough for the nipple of the small baby bottle. The USB dongle is housed inside of the bottle for weatherproofing. A hole is cut in the nipple for a USB cable. Everything is held together with electrical tape as needed.

[Stathack] leaves this antenna on his balcony aiming down the street. He was glad to find that he is easily able to pick up the WiFi signal from the shop down the street. He was also surprised to see that he can pick up signals from a high-rise building over 1km away. Not bad for an antenna made from a spoon and a baby bottle; plus it looks less threatening than some of the cantenna builds we’ve seen.

Knitting In The Round

There have been a few posts on Hackaday over the years involving knitting, either by modifying an old Brother knitting machine to incorporate modern hardware, or by building a 3D printed knitting machine. All of these hacks are examples of flat knitting, and are incapable of making a seamless tube. Circular Knitic bucks that trend by using 3D printing and laser cutters to create an open source circular knitting machine.

Circular Knitic is an expansion on an earlier build that gave a new brain to old Brother knitting machines from the 70s. This build goes well beyond simple manipulation of electrons and presents an entire knitting machine specifically designed for circular knitting. It’s completely automated, so once the machine is set up, a giant tube of knit yarn is automagically created without any human intervention.

This isn’t the first completely open source knitting machine; OpenKnit can be made with aluminum extrusion, some electronics, and a few 3D printed parts. Circular Knitic is, however, the first circular knitting machine we’ve seen, and according to the Github is completely open source.

The creators of Circular Knitic, [Varvara] and [Mar] have been showing off their machine at an exhibition in Zaragoza, Spain called DOERS, where they’ll be knitting for the better part of six months. You can see some video of that below.

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Everyone’s Favorite Energy Meter Hack, Now Wireless

[Kalle] is at it again with more hacks on electricity use meters. This time, the meter has been hacked to stream their data over the aether wirelessly. Now, data can be grabbed from multiple devices simultaneously, making the possibilities for home energy monitoring limitless

The first project [Kalle] did involved finding a meter from China with capabilities similar to (and cheaper than) the Kill-a-Watt meters. Unlike the Kill-a-Watt which spits out analog values, the Chinese meter sent digital information out on a ribbon cable with the bus lines labeled. Since the meter was so hackable, [Kalle] took it even further in this hack.

With those pesky wires out of the way, the device now uses an Arduino Pro Mini to sniff the energy meter’s data stream. Then it transmits the data wirelessly with a nRF34L01+ transceiver. As a perk, all of these chips fit inside the case of the energy meter, making this a very tidy hack indeed. The project code an incredible amount of detail is available on the project site, so be sure to check this one out for all of your energy monitoring needs!

Making Something Useful With The ESP8266

The ESP8266 is the latest and greatest way to get a project connected to the Internet, but so far we haven’t seen many projects that actually do something with this very cool chip. Yes, there are a few people pinging away with AT commands, and there is a thriving community building interpreters and flashing new code on this chip, but not much in the way of actual projects. [Martin] is the exception. He’s come up with two projects that use the ESP8266.

The first project is one that puts the readings from a DHT22 temperature/humidity sensor up on the Internet. Following the spirit of all the recent development of the ESP8266, [Martin] isn’t using an external microcontroller. Instead, he’s using the SDK to run an HTTP daemon using [Sprite_TM]’s code. This web server provides an interface to turn an LED on and off, and reports the temperature and humidity readings from the DHT22. It’s simple, but it’s easy to see how this tiny chip could become the basis for a smart thermostat.

If lighting up LEDs isn’t enough, [Martin] has another project that includes three solid state relays. This one is a bit more complex with MQTT support, a fancy jQuery interface, and support for network time. [Martin] isn’t quite ready to publish the complete code for this project, but that’s only because there are a few features he’d like to implement before making it public. These include dynamic DNS, scheduling functionality, and support for an I2C status display. Even without these fancy features, it’s still a great project that’s still extremely capable for an Internet of Things thing. You can check out [Martin]’s video demo of this board below.

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A Bluetooth Garage Door, Take Three

A few years ago, [Lou] came up with a pretty clever build to open his garage door with his phone. He simply took a Bluetooth headset, replaced the speaker with a transistor, and tied the transistor to a few wires coming out of his garage door opener. When the Bluetooth headset connected, the short beep coming from the speaker output opened the door.

The newest version of this build does away with the simple Bluetooth headset and replaces it with a Bluetooth 4.0 chip. The reason for this is that Apple and their walled garden of an App store would never allow a Samsung Bluetooth headset to be used with one of their iDevices.

The latest build is just about as simple as using a Bluetooth headset. A board that appears to use TI’s CC2540 chip is attached to the garage door opener with a few passives and a transistor. Pairing the new circuit with a phone is as simple as shorting a pair of pins, and the new iOS app does exactly what it should – opens a garage door at the press of a non-button.

While it’s not something that can be put together with scraps from a junk drawer, it’s still an extremely simple solution to opening a garage door with a phone. Video below.

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A Dev Board For The ESP Lua Interpreter

From the great minds behind the NodeMCU Lua interpreter for the ESP8266 comes a proper dev board for the WiFi platform of 2015. They are calling it, the NodeMCU-devkit, and it’s a reasonable, cheap, and breadboardable breakout board for the ESP8266.

The version of ESP8266 used in this project is the ESP-12, the newer, fancier model with RF shielding, a questionable FCC logo, and every single one of the GPIOs exposed on castellated connectors. The rest of the board is a USB to serial converter (the CH340G – probably the cheapest USB to serial chip out there), a few passives, and a USB micro connector. It’s simple, cheap, and open source. You can’t do better than that.

This dev board is explicitly designed to work with the NodeMCU firmware, a Lua-based firmware for the ESP. Already we’ve seen some projects make the Hackaday front page with this firmware. Sure, it’s just a garage door opener, but that’s extremely impressive for a chip that’s only a few months old.

Thanks [Baboon] for the tip.

Skyscraper Tetris Lets the City Know how Good or Bad You Are

If you’ve clocked one-too-many hours at Tetris, it might be time to show the world your skills on this skyscraper-sized display on the Shell Centre in London. [Benjamin], [Tom], and their “army of volunteers” took to the Shell building and assembled their super-screen from a collection of 182 networked wireless lightbulbs, some tracing paper, and mylar to create a playable interface from the Jubilee Gardens below.

[Benjamin] doesn’t deliver many of the technical details on his post, but he does give us an overview. He achieves full wireless coverage of all floors by spacing out 14 TP-Link WR702n routers, each running the same version of OpenWRT. This interface wasn’t [Benjamin’s] first choice, as he would’ve preferred to tap into the building’s existing wireless network; unfortunately, he was left without support from the building’s network team. Equipped with a large donation of wireless bulbs controlled by a central bridge, [Benjamin’s] Python-adaptation of Tetris can refresh the building about about 1-to-2 frames per second. Given his description of the bulb interface, we suspect he’s using the all-too-familiar Philips Hue smart lightbulbs to illuminate the building.

In case you haven’t heard of Faraday’s Christmas Lectures, they’re the UK’s nationally broadcasted “science special” featured at the end of the year and founded in 1825 by [Michael Faraday] himself. The goal of these Lectures is to introduce young people to some aspect from the sciences. We’ve seen giant Tetrises before, but not in a way that inspires such a young audience. We’re thrilled to see that hacking both in software (Python, LAN networks) and hardware (ZigBee, OpenWRT) made the cut for this year’s special. After all, why should MIT keep all the fun to themselves?

If the building-scale is just too big for your taste, why not have a go on your oscilloscope?

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