Wireless Hacks

1047 Articles

A Bluetooth Garage Door, Take Three

January 2, 2015 by 9 Comments

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

January 1, 2015 by 25 Comments

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

January 1, 2015 by 16 Comments

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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Bringing A Legacy Pager Network Back To Life

December 30, 2014 by 24 Comments

[Jelmer] recently found his old pager in the middle of a move, and decided to fire it up to relive his fond memories of receiving a page. He soon discovered that the pager’s number was no longer active and the pager’s network was completely shut down. To bring his pager back to life, [Jelmer] built his own OpenWRT-based pager base station that emulates the POCSAG RF pager protocol.

[Jelmer] opened up his pager and started probing signals to determine what protocol the pager used. Soon he found the RF receiver and decoder IC which implements the POCSAG pager protocol. [Jelmer] began going through the sparse POCSAG documentation and assembled enough information to implement the protocol himself.

[Jelmer] used a HLK-RM04 WiFi router module for the brains of his build, which talks to an ATMega that controls a SI4432 RF transceiver. The router runs OpenWRT and generates POCSAG control signals that are transmitted by the SI4432 IC. [Jelmer] successfully used this setup to send control signals to several pagers he had on hand, and plans on using the setup to send customizable alerts in the future. [Jelmer] does note that operating this device may be illegal in many countries, so as always, check local frequency allocations and laws before tackling this project. Check out the video after the break where a pager is initialized by [Jelmer]’s transmitter.

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WiFi Lamp Challenge – 5 Hour Speedrun

December 24, 2014 by 9 Comments

“We want to get this done quick, not right.”

[CNLohr]’s favorite desk lamp broke, so he gave himself a challenge: convert the lamp to LED and control it via WiFi within 5 hours, from scratch. He video recorded and narrated the whole process and did a nice job of explaining the tricky parts and failures along the way, fast forwarding us through the slow parts.

Some bits and pieces were simple and obvious: gut the old bulb, wire some LEDs, add a few power resistors, toss in a power supply from “like a monitor or something, don’t care” for the LEDs, add in what looks like an LM2596 adjustable power supply for the logic, some kind of ATMega, that new ESP8266 (Wi07C), splice on a power cord, etc. Standard stuff.

To our readers who’s hacks tend to start with soldering irons and screwdrivers, the video shows harder parts of designing an electronics project: creating the PCB in software (he used KiCad), lithographically transferring the circuit to a PCB, bismuth solderpasting & populating the board, and writing and documenting his code on Github. Perhaps most reassuringly, he also showed the consequences of every greedy shortcut and the process of troubleshooting around them.

If you have ever tried to follow a recipe from a cooking show and noticed how easy it all seems when everything is measured and prepped beforehand – and then what a disaster it is when you try it – the same is revealed here. Overall, it is a very thorough demonstration of what it actually takes to design a project – not just perfect circuits and perfect steps to follow.

In the end he got it done in the nick of time an hour late because he cannot add. Close enough.

Thanks [gokkor] for the tip.

A Breakout Board For The ESP8266-03

November 28, 2014 by 32 Comments

In the last few weeks we have been seeing a lot of ESP8266 based projects. Given this WiFi module is only $3 on Ebay it surely makes sense using it as an Internet of Things (IoT) platform. To facilitate their prototyping stage I designed a breakout board for it.

The board shown above includes a 3.3V 1A LDO, a genuine FT230x USB to UART adapter, a button to make the ESP8266 jump into its bootloader mode and a header where you can find all the soldered-on-board module IOs. One resistor can be removed to allow 3.3V current measurement, another can be populated to let the FT230X start the bootloader jumping procedure. All the IOs have 1k current limiting resistors to prevent possible short-circuit mistakes. Finally, the board deliberately doesn’t use any through hole components so you may put double-sided tape on its back to attach it anywhere you want. As usual, all the source files can be download from my website.

Using The ESP8266 As A Web-enabled Sensor

November 23, 2014 by 34 Comments

A few months ago, the ESP8266 came onto the scene as a cheap way to add WiFi to just about any project that had a spare UART. Since then, a few people have figured out how to get this neat chip running custom firmware, opening the doors to an Internet of Things based around an ESP8266. [Marc] and [Xavi] just wrote up a quick tutorial on how to turn the ESP8266 into a WiFi sensor platform that will relay the state of a GPIO pin to the Internet.

If you’re going to replicate this project, you won’t be using the stock firmware on the ESP. Instead of the stock firmware, [Marc] and [Xavi] are using the Lua-based firmware that allows for access to a few GPIOs on the device and scripting support to make application development easy. To upload this firmware to the ESP, [Marc] and [Xavi] needed a standard FTDI USB to serial converter, a few AT commands through a terminal program, and a few bits of wire.

The circuit [Marc] and [Xavi] ended up demoing for this tutorial is a simple webpage that’s updated every time a button is pressed. This will be installed in the door of their hackerspace in Barcelona, but already they have a great example of the ESP8266 in use.