home hacks

1879 Articles

Building A Replacement For A Broken Dehumidifier Controller

April 14, 2013 by 17 Comments

dehumidifier-replacement-controller

We’ve thought of doing a project like this ourselves as the dehumidifier we ordered online runs the fan 24/7 no matter what the humidity conditions. But it wasn’t that [Davide Gironi] was unhappy with the features on his unit. It’s that the dehumidifier controller stopped working so he replaced it with one of his own design. The original humidity sensor was mechanical and simply broke. He used an AVR along with a humidity and frost sensor to get the appliance up and running again.

A DHT22 humidity sensor is polled by the ATmega8 chip and compared to the user-adjustable trimpot value. If it is above that threshold the unit is switched on using one of the relays seen in the image above. The one problem you have to watch out for when using compressor cooled appliances is ice accumulation on the radiator. [Davide] uses a thermistor for temperature feedback, switching the compressor off when it gets below 7C and turning it back on again when it is above 12C.

The replacement still uses the reservoir sensor and indicator LEDs. We, however, would recommend using the watchdog timer on the chip to ensure that it is reset if something goes wrong in the code.

Solar Powered Robot Mows Your Lawn While You Chill Indoors

April 7, 2013 by 47 Comments

We’ve heard quite a number of radio ads lately trying to sell an automatic lawn mowing robot (like a Roomba for your grass). But wouldn’t it be a lot more fun to hack your own from an existing lawnmower? That’s what [Daniel Epperson] did. In fact, the project has been ongoing for years. But he wrote in to share the latest development which adds solar charging capabilities to the robot mower.

First off let’s discuss the fact that this is not an electric lawnmower. This is the Prius of lawnmowers, bringing together hybrid technology to cut the grass with the gasoline powered motor, and to propel the rig with electricity. [Danny’s] worked hard to shoe-horn just about every feature imaginable (other than autonomy) into the thing, and that’s why the batteries can be charged from mains, an alternator powered by the gas motor, and now from the PV panel mounted on top of it. Get the entire project overview in his roundup post.

This a wireless video feed and the mower is driven by remote-controlled. So you can give your yard a trim without getting sweaty. After the jump we’ve embedded a clip of an earlier revision demonstrating that remote control. If you’re not interest in having all the features you could simply build an analog version.

Continue reading “Solar Powered Robot Mows Your Lawn While You Chill Indoors” →

Home Security Hardware Makes You The Monitoring Service

April 4, 2013 by 16 Comments

diy-home-security

[Nick] and [Simon] both have home security systems with a monitoring service who will call whenever an alarm is tripped. For [Simon] this ends up happening a lot and he wanted to change the circumstances that would trigger a call. Because of company policy the service is inflexible, so he and [Nick] went to work cutting them out of the loop. What they came up with is this custom electronics board which monitors the security system and calls or texts them accordingly.

They started with the self-monitoring alarm system design we looked at back in September. This led to the inclusion of the SIM900 GSM modem, which is a really cheap way to get your device connected to the cellular network. It also uses a DTMF touch tone decoder to emulate the phone line to keep the security system happy. [Simon] highlights several changes he made to the design, as well as the reasons for them. One idea he has for a possible revision is to do away with the MT8870 chip which handles the touch tones. He thinks it may be possible to use the SIM900’s DTMF features to do that work instead.

SenseLamp Automates Rooms By Replacing Light Fixtures

April 2, 2013 by 25 Comments

senselamp

Would you believe that this beautiful light fixture is actually a hacked together home automation project? Okay, so this wire mess is the second of three versions that [Christian] built. It replaces a light fixture in the room, but if you look closely you’ll see that there is a compact fluorescent bulb included in the build. The laser-cut frame acts as a bit of a lamp shade, while providing a place to mount the rest of the hardware.

The final version cleans things up a bit, and adds a footprint for the PIR motion sensor that he forgot to design into this version. The idea is that each lamp monitors motion in the room, switching the light on and off again as necessary. A light-dependent resistor ensures that the bulb is only powered up if the room is dark so as not to waste electricity during the day.

The build includes a sensor package that reports back temperature and humidity data. Communications are provided by a WR703N router rolled into each of the four units installed in his house. With this kind of hardware at his disposal it should be a snap to control every IR remote control device in his house via the network by adding an IR LED and some code to the lamps.

Homemade Bocce Balls

March 29, 2013 by 16 Comments

homemade-bocce-balls

For those unfamiliar with it, Bocce Ball is an outdoor game played with a set of heavy grapefruit-sized balls. We’ve never really thought of making our own set, but as you can see above, it can be done. These are six Bocce balls produced at home by [Horvitz444].

It seems the commercially available balls have a cement or clay core covered in a layer of high-impact epoxy. [Horvitz444] was able to recreate this starting with some vacuum forming. He built his own former out of peg board and a shop vac. The plastic stock he used was a light panel from the home store. After heating it up in the oven he formed a mold using what looks like two halves of Bocce balls. The mold halves were melted together using a soldering iron. After pouring in the secret concoction of cement ingredients and letting them harden, he removed the orbs from the molds and ground down the seams until smooth. They were covered in epoxy and painted. Most of these details were gleaned from his comments in the Reddit thread.

Automatic Closet Lightswitch

March 28, 2013 by 33 Comments

closet-door-switch-box

[Dillon] wrote in to tell us about his latest project, an automatic light switch for a the hallway closet in his house. Although this project could probably be done very simply, [Dillon] accomplished everything in a way that actually looks professionally done and has some neat features. Check out his site for more pictures of the build.

Not that we at [HAD] mind a bit of messy wiring, but if it’s going inside a house, neater is always better. On the other hand, this project took nearly a year to go from idea to implementation, so please keep submitting your spaghetti-wired projects.  We understand.

As an electrical engineering major, [Dillon] didn’t skimp on basic electrical components, and has schematics available on his site. A MSP430 microcontroller provides the “brains” for everything, turning the light off after 5 minutes if the doors are not shut. Be sure to check out his video overview after the break with footage of it in action. Continue reading “Automatic Closet Lightswitch” →

Installing GLaDOS In The Ceiling Of Your House

March 25, 2013 by 14 Comments

glados-ceiling-light

Install this light fixture in your bedroom and you might kiss your nights of peaceful sleep goodbye. Fans of the Portal game franchise will recognize it as a smaller version of the megalomaniacal artificial intelligence character from the game. This particular rendition is how she looked in the second installment of the series. The lamp is the creation of [Dragonator]. It was entirely 3D printed before being outfitted with LEDs to actually function as a light.

Our first thought is that this project is all about 3D design to get the final product t0 look so fantastic. But if you dig a little deeper you’ll see that it’s so much more than that. To get pieces that look this fantastic you must have a well tuned printer and be willing to let it run for 40-60 hours as it burns through 2 kg of filament. At that point you’re still far from the finish line as the [Dragonator] then set to work sanding and painting all of the pieces. From there he lovingly assembled everything, including gears and motors to give it motion.

In the end the electronics did not work as he envisioned. But maybe after a bit of time off from all that work he’ll revisit the project and make a bit more progress. For us, the aesthetic already makes the hack. Making it move and sound like the character would be over the top.

If you liked this you can’t miss the GLaDOS potato.