Adding A Timer Feature To This Desk Lamp

December 21, 2012 by Mike Szczys 18 Comments

timer-lamp

[Steven Mackaay] added a simple user interface that implements a shutoff timer for his desk lamp. His project log comes in two parts, the breadboarding and the actual implementation.

He wanted a few things out of the build. The first is an LED that would help him find the lamp in the dark. The second feature is a shutoff timer with different delay options. To get everything working he used a PIC microcontroller to drive a mechanical relay. That relay switches the mains power to the lamps. Now he uses one button to switch the lamp on and off. The other selects a shutoff timer of one, five, or thirty minutes. Power for the control circuitry is provided by the green wall wart PCB seen in the photo of the electronic guts.

This is a pretty general setup that could be applied to a lot of other mains switching applications. Just connect the logic hardware to some type of relay.

Rolling Your Own Furnace Controller

December 11, 2012 by Mike Szczys 17 Comments

replacement-thermostat

[Viktor’s] found an opportunity to put his embedded design skills to use when the furnace controller in his building went out. He admits it would have been much easier to just purchase a replacement, but not nearly as fun. Instead he built this furnace controller based on a PIC 18F4550.

First off, you may find it strange that we’re calling this a furnace controller and not a thermostat. But a study of the hardware schematic reveals that the device doesn’t have the ability to sense temperature. It merely switches the furnace on and off based on a time schedule. We guess this is for an apartment building where measuring the temperature at one central point doesn’t suffice?

At any rate, the build is clean and the UI looks quite easy to use. Inside there’s a board-mounted 12V relay which controls the furnace. The schedule is saved to the EEPROM of the microcontroller and time is kept by a battery-backed DS1307.

We’d love to see this extended in the future. Some possibilities would be adding internet connectivity and implementing a mesh network of temperature sensors which would give feedback to the main unit.

Dimming The Living Room Lights Using Your TV Remote

November 20, 2012 by Mike Szczys 23 Comments

As part of a complete home theater setup [Andy] wanted to be able to control the lights from his couch. He started thinking about the best way to do this when he realized that his TV remote has buttons on it which he never uses. Those controls are meant for other components made by the same manufacturer as the TV. Since he doesn’t have that equipment on hand, he built his own IR receiver to switch the lights with those unused buttons.

He monitors and IR receiver using an AVR microcontroller. It is powered from mains via the guts from a wall wart included in the build. Also rolled into the project is a solid state relay capable of switching the mains feed to the light circuit. [Andy] mentions that going with a solid state part mean you don’t get that clicking associated with a mechanical relay. An electrical box extension was used to give him more room for mounting the IR receiver and housing his DIY circuit board.

Rewiring A Free Carnival Sign

October 23, 2012 by Brian Benchoff 13 Comments

Late last September, Hackaday along with other hackerspaces including North Street Labs, 1.21 Jigawatts, Maker Twins, made their way to the NYC Maker Faire via the Red Bull Creation contest. The objectives of the contest were simple: build a game in 72 hours, have people vote on it, and join the Red Bull crew in Queens for a carnival-like atmosphere.

When the Maker Faire was over, Red Bull had some leftover props from their Midway at Maker Faire setup, including a few illuminated carnival signs. Without any use for them, they graciously gave Hackaday, North Street, Maker Twins and the Jigawatts the signs to their respective rides.

Now that things have settled down and the rides have returned to their home base, the folks over at North Street decided to improve their sign. At Maker Fair, these signs were illuminated by 50 incandescent bulbs, all wired on the same circuit. [Steve] over at North Street had the awesome idea of adding a persistence of vision aspect to the sign, so work began on wiring every fourth bulb in series.

To drive the light circuits, North Street repurposed the Arduino Relay shield originally used for the lights on the Centrifury, their competitive centrifuge and spinning hell of a game. In the video after the break, you can see the addition of POV lights really brings out the carnival atmosphere. A literally brilliant build, and a wonderful addition to the scariest game ever made.

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Cellular Vehicle Information And Control

October 13, 2012 by Mike Szczys 14 Comments

This hardware, which was built as a Computer Engineering project by [Bryon] and his classmates, gives you feedback and control of a car though a cellular phone network. It uses text messages to communicate with a control device. This can be pretty much any cellphone, but in the clip after the break they show off an Android app which puts a pretty GUI in front of you and abstracts away the tedium of specially formatted messages.

At the heart of the system is an Arduino Mega board. It has a cellular shield with an external antennae for connectivity. A GPS device, relay board, and ODB-II module provide feedback and control to the system. The relays allow the car to be started and the doors to be locked. The GPS and ODB-II module can send back location and vehicle information (anything available from the car’s sensors). There were some issues with the text messages being blocked during testing. The team thinks that the automated back-and-forth triggered some kind of spam filter from the telecom.

There’s still more work to be done if they want to actually drive the car via remote control.

Continue reading “Cellular Vehicle Information And Control” →

Home Automation Hack Controls Lights Based On Head Count

September 19, 2012 by Mike Szczys 19 Comments

This home automation hardware turns on and off the lights based on room occupancy. The hack is an extension of an earlier version that was only a proof of concept. [RPisces] took the idea and made it into reality by mounting the sensor hardware in a doorway.

He prototyped the device using the MSP430 launchpad. It monitors a pair of IR distance sensors which record a change when something passes between them and the opposite side of the hallway. This is a good sensor choice as it only requires hardware on one side of the passageway. Because two of them are used, it’s quite simple to figure out if a person is entering or leaving the room based on which is tripped first.

In this case [RPisces] drives a relay to switch a lamp on and off. But it could be used for just about anything. We’d enjoy seeing it trigger an audio system like the one [Quinn’s] installing in every room.

Art Controller: Relay Board With Switches For Timing

September 13, 2012 by Mike Szczys 12 Comments

Meet the Art Controller, a new dev board available over at Evil Mad Scientist Laboratories. It provides a drop-in solution for switching higher voltage loads (but not mains). The thing we like most about it is the ability to alter a switching delay without reprogramming the firmware.

The board uses an ATtiny2313 for control. It’s fed regulated 5V power from the on-board 7805 linear regulator. The relay can handle a 24V DC or 40V AC load, which is targeted at an audience that needs electronic switching for art-related devices but doesn’t want the hassle of designing a circuit every time. This offers a single shot, or repeat action, with that bank of DIP switches selecting a delay from once every second, to every 31 hours. It can get its initial trigger from anything that can pull a pin low, like a button, or a coin acceptor.

Keep this in mind. The open source nature of the project means it could come in handy as a reference design.