Office Dog Triangulation Keeps Spot Accounted For

[Matt Reed] works at a pet friendly work-space, where his pooch called [Bean] loves to wander around and disappear. She’s not getting in trouble, but nonetheless, [Matt] worries about her. So he took the creepy stalker route and put a beacon on her collar to track her every move.

He’s using a small BLE beacon that will poll a signal every second, sending out a unique ID code and a RSSI value (Received Signal Strength Indicator). Normally beacons are placed in a stationary location to help people navigate — but this time, it’s on a moving dog.

In order to better understand [Bean’s] location in the office, [Matt] set up three Raspberry Pi’s with Bluetooth adapters around the office. Using Noble, Node.js listens for the RSSI values and triangulates [Bean’s] position, much like a cellphone can be located using different ping times from cellular towers.

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Building Custom Integrated Circuits

The first integrated circuits weren’t tiny flecks of silicon mounted to metal carriers and embedded in epoxy or ceramic. The first integrated circuits, albeit a looser definition of such, were just a few transistors, resistors, and diodes mashed together in the same package. With this in mind, [Rupert] created his own custom IC. It’s an IR receiver transmitter constructed out of a transistor, resistor, and an LED.

The attentive reader should be asking, “wait, can’t you just buy an IR receiver transmitter?” Yes, yes you can. But that’s not a hack™, and would otherwise be very uninteresting.

[Rupert]’s IC is just three parts, a 2n2222 transistor, a 220Ω resistor and an IR LED. With a good bit of deadbug soldering, these three parts were melded into something that resembled, and had the same pinout of, a Vishay TSOP4838 IR receiver. The epoxy used to encapsulate this integrated circuit is a standard 2-part epoxy and laser printer toner. Once everything is mixed up into a gooey slurry, it’s dripped over the IC producing a blob of an integrated circuit. It’s functionally identical to the standard commercial version, and looks good enough for a really cool project [Rupert]’s been working on.

Thanks [foehammer] for the tip.

First Raspberry Pi Zero Hack – Piggy-Back WiFi.

And we have the first Raspberry Pi Zero hack! In less than 72 hours from the official release announcement [Shintaro] attached an Edimax WiFi USB Adapter directly to the USB solder pads on the Pi Zero. He couldn’t bear to disturb the small dimensions of the Pi Zero by using the USB On-the-Go (OTG). The OTG is needed to convert the micro-USB connector on the board to a full USB-A connector.

The case was removed from the Edimax and the device and Zero wrapped in Kapton to insulate the exposed solder points. Power was taken from the PP1 and PP6 points on the back of the board. These are the unregulated inputs from the USB power so should be used with caution. Some cheap USB power supplies can put out more that 5 volts when first connected and that might let the smoke out of a device.


The data wires were connected to PP22 and PP23, also on the back, and behind the USB data connector. Since USB is a differential signal these wires were carefully kept of equal length to avoid distorting the signal.

An SD card was created and edited on a Raspberry Pi B 2 to set the WiFi credentials. Inserted into the Zero it booted fine and started up the WiFi network connection.

Congratulations, [Shintaro] for the first Hackaday Raspberry Pi Zero hack. Is that a Hack-a-Zero-Day hack?

ESP8266 BASIC WiFi Thermostat is Child’s Play

If you’ve read any of our posts in the last couple years, you’ll have noted that our community is stoked about bringing the Internet to their devices on the cheap with the ESP8266 modules. Why? This forum post that details making a WiFi thermostat really brings the point home: it’s so easy and cheap to build Internet-enabled devices that you almost can’t resist.

When the ESP8266 first came out, there very little documentation, much less code support. Since then Espressif’s SDK has improved, the NodeMCU project brought Lua support, and there’s even Arduino support. Most recently, BASIC has been added to the ESP stable, and that really lowers the barriers to creating a simple WiFi widget, like the thermostat example here that uses a Dallas DS18B20 temperature sensor and an LED as a stand-in for the heater element.

The hardware for this project, a re-build of this demo code from the ESP8266 BASIC docs, is nothing more than a few off-the-shelf parts soldered together. No schematic required.

What makes the project work behind the scenes is some clever code-reuse by [Rotohammer] on the ESP8266 forums. Essentially, he wrapped the Arduino’s one-wire library, giving it simple BASIC bindings. Then all that’s left for the BASIC coder is to read the value and print it out to a webpage.

There’s all sorts of details swept under the rug here, and those of you out there who are used to bare-metal programming will surely huff and puff. But there’s a time for building your own injection-molder to make DIY Lego bricks, and there’s a time to just put blocks together. This project, and the BASIC interpreter that made it possible, demonstrate how much joy someone can get from just putting the parts together.

Power Over WiFi Might Not Be A Unicorn After All

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.

USB energy harvesting dongle.
USB energy harvesting dongle.

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.

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

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 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

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!]