Open Hardware Moodlamp With ATmega

June 5, 2012 by Caleb Kraft 8 Comments

[Daniel Andrade] has built a pretty cool mood lamp circuit. He was initially inspired by [Toon Beerton’s] Ikea lamp, but found he just didn’t have the knowledge to proceed with the PIC processor. He rushed out and bought an arduino to begin learning. Once he figured out how to properly make a mood lamp function, he created a custom circuit to utilize an ATmega chip instead of his whole arduino. He’s now on his second revision of the circuit and is sharing all the files with whoever would like to download them.

His circuit utilizes a 3wRGB LED and any ATmega 8/168/328. He has left some space for expansion on the board as well just in case you’d like to add sensors of some kind (he mentions a temp sensor).

Building An RGB Mood Lamp Using An IKEA Mylonit

June 3, 2012 by Caleb Kraft 12 Comments

[Toon Beerten] had been experimenting with LED lamp construction. He had already built a pretty neat pyramid of LEDs as a mood lamp but wanted something a little higher quality for his living room. He ran out and picked up an IKEA lamp, which you can see above. From the store, the lamp can only display one color, and has a clear construction. [Toon] wanted RGB and an opaque finish, so he sanded the lamp and built a custom circuit.

He tore out the lamp circuit and replaced it with his own, consisting of a 3W LED, a heatsink, and a PIC 16F628 (and the supporting components). The main circuit actually fits underneath the lamp pretty well. You can download the full schematics and code from his site if you’d like to replicate it.

As you can see in the video, the effect is quite nice.

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Charting The Efficiencies Of Boiling Water

June 2, 2012 by Brian Benchoff 32 Comments

Water takes a lot of energy to heat up. If you’d like evidence of this, simply jump into a 50° F swimming pool on Memorial Day. Despite the difficulty of heating water, that simple act accounts for a lot of industrial processes. From cooking a steak to running a nuclear reactor, there isn’t much that doesn’t involve heating water.

[Tom Murphy], Physics prof at UCSD decided to test out exactly how efficiently he could boil water. Armed with a gas stove, electric kettle, microwave, and a neat laser pointer/photodiode setup on his gas meter to measure consumption, he calculated exactly how much energy he was using to make a cup of tea.

The final numbers from [Tom]’s experiment revealed that a gas stove – using a pot with and without a lid on large and small burners – was about 20% efficient. A gas-powered hot water heater was much better at 55% efficiency, but the microwave and electric kettle had a miserable efficiencies of around 15 and 25%, respectively. There is a reason for the terrible inefficiency of using electricity to heat water; if only the power from the wall is considered, the electric kettle put 80% of energy consumed directly into the water. Because the electricity has to come from somewhere, usually a fossil-fueled power plant that operates at around 30% efficiency, the electric kettle method of turning dinosaurs into hot water is only about 25% efficient.

The take-home from this is there’s a lot of power being wasted every time you run a bath, make some coffee, or wash the dishes. We would all do better by decreasing how much energy we use, much like [Tom]’s efforts in using 5 times less power than his neighbor. Awesome job, [Tom].

Adding Voice Labels To Real Life Objects For The Visually Impaired

June 1, 2012 by Caleb Kraft 7 Comments

[Matt Oppenheim] wrote in to share his work with us. He has been modifying the interfaces of electronics for the visually impaired. It started off with cassette decks. As [Matt] points out, many people who are visually impaired use cassettes for their audio books and newspapers. [Matt] added some touch sensors to the buttons so that he could have something announce what each button was as the user felt them. This allowed them to quickly learn the layout of the device.

After finding that the simple interface on the cassette player was learned very quickly, thereby making his addition no longer needed, he decided to go after something a little more complex. [Matt] set out to modify a digital radio with many more buttons that are less touch friendly. As you can see in the video after the break, he was able to pull this off quite nicely.

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Building The Backend Of Internet Controlled Devices

May 28, 2012 by Mike Szczys 2 Comments

[Adam] and [Jeremy] took on the challenge of designing a system that would make it easy to control appliances from the Internet. We’ve seen the concept many times before; it involves some method of switching mains power and connecting that mechanism to the Internet. This design is both well planned and nicely executed.

We’re always very interested in the power switching for a project like this. It’s good that an approved electrical box houses all of the high-voltage parts in the project. Here a GA8-2B02 solid state relay switches power between the incoming cord and the two outlets. We didn’t get a look in the box, but hopefully there’s a partition between those wires and the low-voltage control wiring which uses a standard 3.5 mm audio jack as an interconnect.

An ATmega644 drives the control signal for the relay. It’s connected via Ethernet cable to the Internet through the use of an ENC28J60 chip which takes care of LAN communications. This is essentially a light-weight web server that will be easy to adapt to receive commands from just about any web-connected sender.

[Thanks Bruce]

Lighting Up A Runway Into The Garage

May 25, 2012 by Mike Szczys 21 Comments

[Timo] didn’t want to look like every other lighted driveway but using solar path lights. Instead he decided to light it up as if it were a runway. It’s easy to look at the result as cute and move on to the next hack. But look again. If you were going to do this yourself how would you implement it considering a car will drive over it, and it’s outdoors?

The first issue of protecting this from traffic is actually not too tough in this case. [Timo’s] driveway is made of pavers and is not a solid sheet of asphalt or concrete. He drilled out some of the intersections to make just enough room for each of the PCBs he etched to house the LEDs and host the driver. These boards are inserted horizontally into the sand between the pavers like a fin, with the surface mount LED positioned along the edge. Power and control wires run along each line of lights. They are serial controlled which cuts down on the number of conductors needed. [Timo] didn’t mention weather proofing but we’d suggest casting them in crystal clear resin just like this headphone amplifier.

DIY Solar Collector Boost Your Hot Water System

May 24, 2012 by Mike Szczys 23 Comments

This home is heated by a wood stove in the winter, which also produces hot water. But the other three seasons it’s an electric water heater that does the work. This latest hack is a solar collector meant to take over the hot water production work for the house. it uses basic building materials and rudimentary construction skills, making it much more approachable than trying to make electricity from the sun.

It’s really just a wood box with a glass lid. The inside has been painted black, and the black tubing that snakes through it holds the water. A three-way valve lets the homeowner patch into the hot water reservoir. The collector is lower than the reservoir, so the heated water makes its way back into the tank as cooler water takes its place. Not bad for an entirely passive system!

[Thanks Minde]