Power Over WiFi Might Not Be A Unicorn After All

November 27, 2015 by Brandon Dunson 54 Comments

There have been a few reports of power over WiFi (PoWiFi) on the intertubes lately. If this is a real thing it’s definitely going to blow all of the IoT fanboys skirts up (sorry to the rest of you *buzzword* fanboys, the IoT kids flash-mobbed the scene and they mean business).

All of the recent information we found points to an article by [Popular Science] titled “Best of What’s New 2015”. The brief write up includes a short summary lacking technical info, and fair play to [PopSci] as it’s a “Best Of” list for which they hadn’t advertised as an in-depth investigation.

However, we tend to live by the “If you’re gonna get wet, you might as well swim.” mentality, so we decided to get a little more information on the subject. After a bit of digging around we came across the actual article on [Cornell University]’s e-print archive where you can download the PDF that was published.

The paper goes into detailed explanation of the power harvesting theory including a schematic of the receiving end hardware. They had to create a constant transmission for the harvester to get over its minimum required voltage of operation. This was done with one of the wireless router’s unused channels to fill the voids of packet-less silence between normal WiFi communication.

As you can imagine PoWiFi is currently limited to powering/charging very low power devices that are used intermittently. The research team was able to charge a Jawbone headset at a rate of 2.3mA for 2.5 hours which resulted in the battery going from 0-41%. The punchline here is the distance, the device being charged was only 5-7cm from the PoWiFi router which is getting close to inductive charging range. The researchers stated in the paper that they were looking into integrating the harvesting circuitry and antenna into the headset while working towards a larger charging distance.

Rate of update vs time.

WiFi packets and silence.

Power harvesting schematic.

At the time of writing this article it seems that PoWiFi is best suited for devices such as: low powered sensors and motion activated cameras that have increased energy storage capacity, which the team mentioned as one of the continued research possibilities.

We’ve covered numerous wireless power projects before, some legit and some we still get a kick out of. Where do you think this one falls on that spectrum? Let us know in the comments below.

Thanks to [ScottVR] for the tip.

Absurd Clock Uses Twelve ESP8266 Modules

November 26, 2015 by Elliot Williams 15 Comments

Quick quiz: How many ESP8266 modules do you need to make an LED clock? Hint: a clock displays 12 hours.

Nope! Twelve is not the answer. But that didn’t stop Hackaday.io user [tamberg] from building a 12-ESP clock during the Bilbao, Spain Maker Faire. The “advantage” of using so many ESP8266s is that each one can independently control one hour LED and its associated slice of five minute-marker LEDs. Each ESP fetches the time over the Internet, but only lights up when it’s time.

It’s like parallel processing or something. Or maybe it’s redundant and failsafe. Or maybe it’s just an attempt to put the maximum Internet into one Thing. Maybe they had a team of twelve people and wanted to split up the load evenly. (We couldn’t think of a real reason you’d want to do this.)

All snark aside, the project looks great as you can see in this Flickr gallery, and all of the design files are available if you’d like to re-use any parts of this project. We’re thinking that the clock face is pretty cool.

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The Internet Of Minecraft Things Is Born

November 25, 2015 by Dan Maloney 10 Comments

Minecraft has come a long way since [Notch] first thought up the idea that would eventually make him a billionaire. The game can be enjoyed on so many levels and become so engaging that grown adults who should know better spend far more time playing it than working on, say, their backlog of Hackaday posts. As if that weren’t bad enough, now Minecraft threatens to break out of screen with the ability to control a WiFi light bulb from within the game.

For those unfamiliar with Minecraft, it’s an open world game that allows players to interact with blocks of various materials. Players can build, destroy, explore and create landscapes and structures. An active modding community contributes everything from cosmetic texture packs to new block types with extended functionality. It was one of these mods that was leveraged to “break the fourth wall” in Minecraft. [giannoug] used the OpenComputers mod, which allows placement of programmable in-game computers with a full complement of peripherals, including an Internet connection. That allowed [giannoug] to send commands to his Brand X eBay WiFi light bulb, the protocol for which his friend [Thomas] had previously reverse engineered. Flip a switch in Minecraft and the real-world light bulb comes on instantly. Pretty cool.

We’ve seen quite a few builds where Minecraft blocks inspired real-world lamps, but this is a step beyond and might be a great way to get kids into programming using Minecraft. But it’s not the first time Minecraft has broken the fourth wall – check out this 2012 effort to build a microcontroller-based Minecraft server that can toggle pins from within the game.

[Thanks to aggvan and Stathis K for the near-simultaneous tips!]

Akiba’s Awesome Lighting Tutorial

November 19, 2015 by Nava Whiteford 3 Comments

[Akiba] over at FreakLabs just put up a detailed tutorial outlining how to control and sequence lighting wirelessly using an Arduino and Vixen lighting sequencer software.

For those that don’t know [Akiba], he’s the guy behind Wrecking Crew Orchestra (TRON Dance) and their EL wire costumes. [Akiba] hacks on his projects at Hacker farm out in rural Japan.

In the tutorial, he sets up a simple 6 LED circuit on a Fredboard (an Arduino compatible board with integrated breadboard). [Akiba] then describes configuring the Vixen sequencer software to control the Arduino, providing simple example code to decode the Vixen serial protocol. Finally [Akiba] shows how to use the ChibiArduino protocol stack to build a wireless illumination system.

[Akiba] has used these tools in many stage performances including with the Wrecking Crew Orchestra (shown above) and the world number 1 flair bartending crew, UPT.

This tutorial is particularly awesome, as it includes both step-by-step videos and a text reference. The videos give a great overview of the process, while the text provides a handy reference to refer to as you hack on your own illumination projects.

Thanks for the writeup [Akiba]! With Christmas just round the corner we hope to see readers using these techniques in their own festive illuminations soon!

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Audio-coupled Smoke Alarm Interface Sends Texts, Emails

November 16, 2015 by Dan Maloney 18 Comments

The Internet of Things is getting to be a big business. Google’s Nest brand is part of the trend, and they’re building a product line that fills niches and looks good doing it, including the Nest Protect smoke and CO detector. It’s nice to get texts and emails if your smoke alarm goes off, but if you’d rather not spend $99USD for the privilege, take a look at this $10 DIY smoke alarm interface.

The secret to keeping the cost of [Team SimpleIOThings’] interface at a minimum is leveraging both the dirt-cheap ESP8266 platform and the functionality available on If This Then That. And to keep the circuit as simple and universal as possible, the ESP8266 dev board is interfaced to an existing smoke detector with a simple microphone sensor. From what we can see it’s just a sound level sensor, and that should work fine with the mic close to the smoke detector. But with high noise levels in your house, like those that come with kids and dogs, false alarms might be an issue. In that case, we bet the software could be modified to listen for the Temporal-Three pattern used by most modern smoke detectors. You could probably even add code to send a separate message for a CO detector sounding a Temporal-Four pattern.

Interfacing to a smoke detector is nothing new, as this pre-ESP8266 project proves. But the versatile WiFi SoC makes interfaces like this quick and easy projects.

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Polyakov Direct Digital Synthesis Receiver

November 15, 2015 by Al Williams 4 Comments

Direct conversion receivers are popular among ham radio operators and others who build radios. Suppose you want to listen to a signal at 7.1 MHz. With a direct conversion receiver, you’d tune a local oscillator to 7.1 MHz, and mix it with the incoming signal. The resulting sum and differences of the input frequencies will include the audio of an AM signal on the desired frequency.

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VOCore Tutorial Gets You Started With Tiny Router

November 15, 2015 by Elliot Williams 18 Comments

[Vadim] wrote up this short but sweet tutorial on getting started with the Vocore (tiny) OpenWRT-router-on-a-stamp. If you need more computing power than you can get with an ESP8266, and you want an open-source Linux-plus-Wifi solution in a square inch of board space, the Vocore looks pretty sweet.

We covered the Vocore a while ago. It has 28 GPIOs, all accessible from system calls in OpenWRT. It becomes much more computer-like if you add a dock that breaks out the USB and Ethernet functionality, but that also doubles the price.

Getting started with a no-frills Linux box (chip?) can be intimidating. So it’s a good thing that [Vadim] details a first setup of the Vocore over WiFi and SSH, and then takes you through a button-and-LED style ‘Hello World’ application that makes simple use of the GPIOs.

He says he’s going to interface it eventually with a TI CC110 sub-gig radio unit, but that’s going to involve writing some drivers and will take him some time. We’d love to see how to connect peripherals, so we’re waiting with bated breath.

[Vadim] also helpfully included an un-bricking script for the Vocore, which restores the default firmware and gets you out of whatever hole you’ve managed to dig yourself into. Basically, you connect to the device over a USB-Serial adapter, run his script, and you should be set.

Any of you out there using a Vocore? Or other OpenWRT routers? Give [Vadim]’s tutorial a glance and let us know what you think.