Monitoring a solar array output

April 23, 2012 By Leave a Comment

After years of hoping and wishing [Dave] finally took the plunge and installed solar panels on the roof of his house. He’s got twelve panels that are each rated at 240 Watts! But just having them sitting there and pumping power back to the grid isn’t enough. Understandably, he decided to add his own solar array monitor so that he could see just what those babies are bringing to the party.

The solar array has an inverter which takes the DC from the cells and converts it to mains voltage AC for use on the grid. The system includes a panel meter which you’d normally find on the supply to the house. All he needed to do is find a way to grab the data from that device. It’s an Elster meter, and offers two types of feedback: a blinking LED that corresponds to each Watt-hour passing through the meter, and an IrDA port which provides a more error-proof method of reading data. Monitoring the 1 Wh pulse is quite a popular method for keeping track of your electric meter, but if your hardware misses a pulse the data will be off. [Dave] chose to use a light sensor to monitor the IrDA output, which is encoded data. As long as you can read the protocol, which has been published by Elster, a transmission can be missed now and again without disturbing the overall power consumption data.

Filed Under: green hacks, home hacks Tagged With: , , ,

An easy to build cat feeder driven by a DIY linear actuator

April 21, 2012 By Leave a Comment

cheap-and-easy-cat-feeder

[Will Finucane] of Revolt Labs/Mad Science Blog was looking for a way to keep his cats happily fed while away on a short vacation, so he put together a cheap and easy automatic feeder to ensure that his pets didn’t go hungry while he was away.

We’ve seen different iterations of automatic pet feeders here before, some relying on rotating false bottoms, while others use crank-style feeders to get the job done. [Will’s] solution is a bit different, employing a cheap linear actuator to deliver feedings.

He emptied out a glue stick, replacing the glue with a brass tube. This gives him the rigidity that the glue lacked, allowing him to easily move a platform full of cat food up and down. He mounted the glue stick on a continuous rotation servo, installing the actuator and a feeding platform inside a cardboard box.

Using an Arduino, he lowers the movable platform every 12 hours, allowing a bit of cat food to fall from the hole he cut in the side of the box. While his creation might not stand up to years of use, it’s a quick solution that can cost very little, depending on what you have sitting around.

Check out the video below to see [Will’s] cat feeder in action.

[Read more…]

Filed Under: arduino hacks, home hacks Tagged With: , , ,

Monitoring air quality with a $12 sensor

April 19, 2012 By Leave a Comment

[Chris] has allergies, asthma, and uses a wood burning stove. You can imagine why testing his air quality might be something he’d be interested in. He has a very nice $290 laser particle counter, but was really curious how the $12 sharp sensor he found would stack up. To find out, he plugged it into an arduino and started logging both on pachube.

After a few different tests, like lighting a match, blowing it out, and letting the smoke flow into the sensors, he decided he needed something better. Cooking some pancakes turned out to be his ultimate method. After charting the dissipation of particles after cooking a nice batch of griddle cakes, he found the two sensors to be surprisingly similar.

Filed Under: home hacks Tagged With:

Ethernet over telephone wire

April 18, 2012 By Leave a Comment

When [Bobo1on1] upgraded his Internet connection from ADSL to Fiber he ran into an issue of actually getting that speed to his desktop computer though his LAN setup. Before he had been using a telephone extension wire which ran from where the DSL entered the house, through a splitter, to his computer where the modem was located. Now that the router used by the fiber system is located at teh entry point, he has no easy way to run Ethernet cable to his computer room. Wifi is predictably slower than the 50mbit WAN connection, and he was unable to use the telephone cable as Ethernet directly.

The solution turns out to be a pair of TP-Link home plug adapters. These are designed to use your home’s mains wiring for data transfer. But [Bob] rigged it up so that they can push 224 mbits/sec over the telephone wire. Since you can’t run mains voltage through the telephone wire he had to hack a method to separate power for the devices from the data I/O. This was done with an external power supply and some passive components for filtering. The drawback is that this is half-duplex so up/down communications cannot happen at the same time.

Filed Under: home hacks Tagged With: , , , , ,

Aquarium automation keeps the fish fed and the lights on

April 14, 2012 By Leave a Comment

fish-tank-automator

Anyone who owns a fish tank knows that a good amount of care is required to keep fish happy, healthy, and most of all – alive. [Vicente Jiménez] usually has no problem keeping up on the day to day maintenance such as feeding and switching the tank light, but he wanted to automate these processes for times when he can’t be home to take care of the fish (Translation).

His aquarium automation project is meant to cover three separate parts of the operation: light control, feeding, and pump regulation during feeding times. [Vincente] picked up an STM8L Discovery board to control his system, which enabled him to easily control the automation of all three.

He constructed the feeding mechanism using an old cassette player motor, which turns his food drum (an old film canister), twice a day at specified feeding times. Before the drum is turned to dispense food, the STM8L turns off the aquarium’s pump via a relay to ensure it doesn’t get clogged in the process. During the day he keeps the tank illuminated, but once night falls, the microcontroller shuts the lights off so the fish can get their rest.

There’s no video of the system in action, but [Vincente] has detailed its construction pretty thoroughly in his blog, so be sure to check it out if you are in need of something similar.

Filed Under: home hacks, Microcontrollers Tagged With: , , ,

Stair accent lights made from cheap LED strips

April 13, 2012 By Leave a Comment

We really like [Geert’s] take on accent lighting for his stairs. He built his own LED channels which mount under the bullnose of each step. The LED strips that he used are actually quite inexpensive. They are RGB versions, but the pixels are not individually addressable. This means that instead of having drivers integrated into the strip (usually those use SPI for color data) this strip just has a power rail and three ground rails for the colors. Ten meters of the strip cost him under forty dollars.

He did want to be able to address each step separately, as well as mix and match colors, so he designed the driver board seen above to use a set of TLC5940 LED drivers. These are controlled by the Arduino which handles color changing and animations. It will eventually include sensors to affect the LEDs as you walk up the stairs. Each strip is mounted in a piece of angle bracket, and they’re connected back to the driver board using telephone extension wire.

Filed Under: home hacks, led hacks Tagged With: , , , ,
« Older Posts
Newer Posts »