TI Chronos Watch Monitor Your Sleeping Infant

July 4, 2012 by Mike Szczys 21 Comments

[Bill] wants a little piece of mind when his infant is sleeping in the other room. For him, the audio-only baby monitor could use some improvement. His proof-of-concept is that blue patch Velcroed on the swaddled infant. It monitors movement, orientation, and temperature and alerts you when something’s amiss.

Inside the pouch you’ll find a TI Chronos eZ430 wristwatch with the band removed. It’s a nice hardware choice because it includes an accelerometer, temperature sensor, and RF link to a USB dongle. [Bill’s] code sends a data packet to the PC about once a second. The PC watches to make sure there’s slight motion, indicating the baby is breathing. This part doesn’t work all that well as the accelerometer doesn’t pick up tiny movements all too well, but it does have potential. In the video after the break you can see the functions which make sure the baby doesn’t roll onto its belly, and that she’s not too cold do work extremely well.

We wonder if the accelerometer would pick up more motion if the watch was hung from a string inside of a small enclosure. This way it would swing back and forth with small movements. But perhaps that would make the whole thing too bulky?

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[RobB’s] House Has No Light Switches

July 4, 2012 by Mike Szczys 46 Comments

So [RobB] wanted to take out all the light switches in his house. His plan was to replace them with a system that could be operated from his smart phone. But his wife insisted that there still must be some way to control the lighting directly — we have to agree with her on that one. The solution was to develop a system that switches the lights via a touch sensor or by Bluetooth.

The touch part of the project is pretty easy. He coated the back of a blank outlet plate with tin foil and hooked it to a microcontroller with a couple of resistors. He’s using an ATtiny85, which can be programmed using Arduino sketches, so the software side is made easy by the CapSense Library. The chip also uses the software serial library to communicate with a Bluetooth module. You can see the result of both in the demo video after the break.

Of course you need to throw a relay in there to switch mains, and find a way to power the uC and Bluetooth module. [RobB] went with a tiny plug-in USB power converter and managed to fit everything in a single-gang switch.

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Timer-based Cooling Helps Your Network Survive The Summer

July 2, 2012 by Mike Szczys 24 Comments

Start your week off with a smile thanks to the video [Sammy] put together. It shows off the cooling rack he made for his network equipment. The project was developed out of necessity as the summer weather was causing his modem and router to heat up and at some point one of them would just shutdown and refuse to work again for hours. We haven’t run into this ourselves but it’s good to know that over-temperature safeguards have been built into the equipment.

His solution was to build a rack that offers fan cooling above and below the two pieces of equipment. As with most of his projects, we think making the video (embedded after the break) was half the fun. In addition to playing around with a turntable for some extra special camera effects he gives us a good view of the overall build. The base includes spacers and velcro strips to hold the equipment in place above a pair of exhaust fans. The standoffs at each corner of the rack suspend a second pair of fans above the equipment. But it wouldn’t look nearly as good without some custom LED effects thrown into the mix.

This is purely timer-drive. It’s a plug-in module that uses mechanical timing to switch mains. But some creative circuitry (or a small microcontroller) could implement temperature-based switching instead.

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Computer Desk… Literally

June 30, 2012 by Mike Szczys 28 Comments

This piece of furniture begs the question, why think of a desk and a computer case as separate things? It combines Ikea furniture with electronic hardware to create the ultimate command center.

First the obvious parts: there’s a nook for the computer case that hangs just below the desktop off to the side, and the twin displays are mounted front and center. The divider between the cabinet pieces was cut away to allow the monitors to be wall-mounted. But things start to get interesting to the left of those monitors. You can see a series of dial displays in the door for that cabinet. Those meters were sourced from the MIT Flea Market and after a bit of alteration they display CPU load information fed to them by an Arduino board. This also drives some LED strips which are mounted behind the frosted glass panel that we guess could be called a back splash. The heavier the load, the better the light show.

All of the power management is taken care of in the cabinet to the right of the monitors. The top row hides a printer, external hard drive backup system, and several gaming consoles. Heat will be an issue so exhaust fans were added to each of these partitions. They’re switched based on a temperature sensor in each. It’s a lot of work, but the outcome proves it was worth it.

[via Reddit]

Roll Your Own Battery Backup System

June 28, 2012 by Mike Szczys 16 Comments

[Chris] and [Dom] wanted to build their own battery backup system on the cheap. They were very creative in sourcing the parts, and ended up putting together a battery-backed CCTV system for about eighty bucks.

Since short power outages are fairly common in the area this battery backup makes sense. We’ve seen some pretty gnarly whole-house systems but this is more of a novelty. That’s a good thing, because the hacking duo decided to reuse batteries which were headed for the scrap yard. They’re connected to a trickle charger which makes sure that they’re continually topped off when mains power is energized. But when there’s a blackout a relay switches an outlet box over to the inverter (also a used part).

The system is outlined in the entertaining video after the break. You’ll see they guys show off the completed build, followed by a walk through of the circuit they designed and how it functions.

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Are You Smarter Than A Raccoon?

June 22, 2012 by Mike Szczys 63 Comments

[Ben] has a raccoon problem. It seems that it’s not uncommon for him to come face-to-face with a pesky raccoon in the middle of the night, in his living room. We think most people would solve the problem by preventing the raccoon from entering the home. But [Ben] just seems hell-bent on catching him. Most recently he’s added motion-sensing to a live trap which he installed…. in his living room.

So [Ben] has cat’s which that to roam at night. They have free range thanks to a cat door which the hungry pest has been exploiting. Apparently the masked robber has a taste for cat food and that’s what keeps him coming back. [Ben] has been using the cat dish as bait but up to this point the live trap hasn’t worked. You see the raccoon isn’t going inside to get the food, but reaches through the cage and pulls pieces out one at a time. The solution is to put up a solid surface around the cage, and hope that the motion sensor will get him this time. Although we’ve linked the most recent post above, you’ll want to page through his blog for the whole story.

Wouldn’t it be better to install some kind of automatic lock that only lets in the kitty?

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Motion Sprinkler Chases Away Defecating Dogs

June 18, 2012 by Mike Szczys 36 Comments

Don’t want dogs pooping on the front lawn? You could put up a sign, your could chase them away like a crotchety old miser, or you could build a motion detecting sprinkler system. It’s pretty hard to line up for a doody when you’re getting sprayed in the face (or worse) with cold water.

The setup is pretty simple. The bump-in image above shows the view from a webcam. The server monitoring the video is running software that detects motion between one frame and the next. When it sees something in the right position it signals an Arduino to trigger the solenoid which has been holding back the water. Check out the movie after the break which shows [Phil Tucker] tramping across the grass to trigger the trap.

Sprinkler hacks are always a lot of fun. This variable-range sprinkler is still one of our favorites.

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