Rack Mount Home Automation With A RPi

February 6, 2013 by Eric Evenchick 19 Comments

[Patrick] wanted to have centralized sensing and control over various parts of his house. His Raspberry Pi Home Automation System integrates a bunch of functionality in one rack mount package, salvaged from an old network switch.

The automation system is based on a Raspberry Pi running Arch Linux, which talks to an ATmega over SPI. We’ve seen this setup used many times before to add additional ports to the Raspberry Pi, but what makes [Patrick]’s build unique is the amount of control he’s built into the system.

The box controls outdoor lighting at sunset and sunrise, generates wakeup calls, controls IR cameras, and plays sounds based on events. It’s capable of monitoring sump pump water level, the state of a house alarm, and more. A custom REST API is used to interact with the device. This allows for programs on any platform to interface with his home, and acts as an API for his house.

[Patrick] provides a lot of details in his build log, which should be helpful to anyone looking to roll their own home automation system. The source is also provided.

Re:load, An Open Source Dummy Load

February 6, 2013 by Eric Evenchick 14 Comments

When testing power supplies or LEDs, a constant current dummy load is needed. These devices will draw a constant amount of current, regardless of the voltage at the input terminals.

[Nick] was looking for a load to test out a power supply, and found commercial offerings to be too large, too powerful, and most importantly, too expensive. This lead to the design of the Re:load, his open source alternative.

Like other constant current sources, the Re:load uses an opamp to control a pass element. While most constant current loads will just use a transistor, [Nick] opted for a BTS117 smart low side switch IC. This device has a built in current limiter, over-voltage protection, over-temperature protection, and short circuit protection, which makes it much safer. The project write up goes into detail on how the device works.

If you need a constant current load, [Nick] is selling kits on Tindie. All the design files are available on Github so that you can build your own.

Quick Fixes For SMD Population Problems

February 5, 2013 by Mike Szczys 33 Comments

Here’s a collection of tricks to get over some surface mount prototyping issues the next time you find yourself in a bind. But first we have to address the soldering atrocity seen on most of the components above. [Rxdtxd] admits he’s using a firestick for soldering his SMD parts. The non-brand 40W iron is just about the worst thing he could be using (well, we guess a candle would be worse). Try to overlook those joints and enjoy his solutions to a couple of other problems.

First up is what to do when you lift a fine-pitch trace like would be found on a TQFP footprint. The fix for this is to grab a junked transformer and use a bit of the enameled wire from the wrappings as a jumper. The wire is quite fine, and the insulation will burn off when soldered which means you don’t need to strip it first.

The second and third tricks both deal with resistors. As you can see above he placed two 1K resistors on a single resistor footprint to make his 2k resistor. The 0603 packages were both soldered standing on end, then connected with a lead from a through-hole component. The other resistor hack piles five components on top of each other to build resistance in parallel. This is not a great idea as it will fail over the long-term, but it will get you though the prototyping stage as long it doesn’t require precise tolerance.

One Kindle Launcher To Rule Them

February 5, 2013 by Mike Szczys 18 Comments

kindle-launcher

Ask around and chances are you can find a friend or family member that still has their early generation Kindle but doesn’t use it anymore. There are quite a number of different things you can do with them, and now there’s a single Launcher that works for all models of hacked Kindles. KUAL is the Kindle Unified Application Launcher.

Loading the launcher on your device does require that it be Jailbroken/Rooted, but that’s really the entire point, right? Once on your device the system is easy to configure. Menus themselves can be customized by editing the XML and JSON pair for each list. The screenshot on the left illustrates some of the applications you might want to run. We could see a VNC viewer being useful, and everyone likes to have games — like Doom II or the entire Z-machine library — on hand when they unexpectedly get stuck somewhere. But MPlayer? Does anyone actually use their ePaper device to watch videos?

BASH Games

February 5, 2013 by Mike Szczys 18 Comments

Get serious about your shell scripting skills and maybe you can pull this one off. It’s a game of snake played in a BASH shell. It seems like a coding nightmare, but the final product turns out to be organized well enough for us to understand and took less than 250 lines of code.

[Martin Bruchanov] started on the project after pining for an old DOS game called Housenka. It’s another version of the classic Snake game which we’ve coded ourselves and seen in several projects including this head-to-head version using musical recorders as controllers. When using a terminal emulator capable of ANSI sequences the game is displayed in color using extended characters.

We give [Martin] bonus points for the way he wrote about his project. It describes the mechanics most would be interested in, like how the user input is captured and what drives the update function and food generation. The rest of the details can be gleaned by reading through the code itself.

Introducing The Deconstruction: A Collaborative Experiment

February 5, 2013 by Caleb Kraft 12 Comments

The goal of The Deconstruction is to bring people together (physically and digitally) to share ideas, collaborate, create, problem solve, and have a good time. The event is open to anyone, anywhere, of any age and skill level.

If you enjoy a bit of good competition and feel like taking on a little bit of a challenge, you should definitely check out The Deconstruction. This event pits a bunch of teams from all over the place against each other in a timed hack-a-thon. The whole time they are building their project, they’re broadcasting live using their webcams too.

If this brings to mind the Red Bull Creation contest, it is because the root idea is from the same guy [Jason Naumoff], but this is NOT a RedBull thing. When I met with him last year in New York, he clued me in that he was working on something much more open ended and inclusive. The Deconstruction is that thing. He explained that they’re really hoping to reach out to families, clubs, and high school groups as well as the usual hackerspaces.

Join up, make something cool, have fun.

Military Steals Idea Of Anyone Who Ever Tied A Cellphone Camera To Quadcopter

February 5, 2013 by Mike Szczys 62 Comments

spy-helicopter

Check out the toy this solder is using. It’s a tiny remote-controlled helicopter. The thing comes in a kit that includes a small tablet through which the nose-mounted camera image can be viewed. These are in use in Afghanistan by the UK Military. The purpose is to help protect foot soldiers by allowing them to perform discrete reconnaissance. What would you pay for this type of life saving technology? How does $31 million for 160 units sound? For that price we expect eight propellers and a cinema quality camera.

The drone is manufactured by Prox Dynamics. They’ve been in development since 2008 and you can bet that a lot of that time went into making it “inaudible” which is the main difference we see between this and hobby-built versions. For now you’ll have to deal with trying to make your own since they will only sell to the government.

The best we can do for you when it comes to video of the thing is prototyping footage from 2009 (after the break). If you have a link to a newer clip we’d love to see it in the comments.

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