Hackaday Prize Entry: Theia IoT light-switch

There are it seems no wireless-enabled light switches available in the standard form factor of a UK light switch. At least, that was the experience of [loldavid6], when he decided he needed one. Also, none of the switches he could find were open-source, or easy to integrate with. So he set out to design his own, and the Theia IoT light switch is the result.

In adapting a standard light switch, he was anxious that his device would not depend on the position of the switch for its operation. Therefore he had to ensure that the switch became merely an input to whichever board he designed, rather than controlling the mains power. He settled upon the ESP8266 wireless-enabled microcontroller as the brains of the unit, with a relay doing the mains switching. He first considered using an LNK304 off-line switching PSU chip to derive his low voltages, but later moved to an off-the-shelf switch-mode board.

So far two prototype designs have been completed, one for each power supply option. Boards have been ordered, and he’s now in the interminable waiting period for international postage. All the KiCad and other files are available for download o the project’s hackaday.io page, so you can have a look for yourselves if you are so inclined.

You might ask why another IoT light switch might be needed. But even though they are now available and inexpensive, there is still a gap for a board that is open, and more importantly does not rely on someone else’s cloud backend. Plus, of course, this board can be used for more than lighting.

Light bulb image: Осадчая Екатерина (Own work) [CC BY-SA 4.0], via Wikimedia Commons.

Infrared-controlled Light Switch

If you’re looking for your first electronics project, or a project to get someone else started in electronics, [Vadim] has you covered. Back when he was first starting out in electronics he built this infrared-controlled light switch that works with a standard TV remote control.

[Vadim]’s first few projects ended up as parts for other projects after they were built, so he wanted to build something useful that wouldn’t ultimately end up back in the parts drawer. The other requirements for the project were to use a microcontroller and to keep it simple. [Vadim] chose an ATtiny2313 to handle the RC-5 IR protocol and switch the light.

The circuit still has a switch to manually control the lights, preserving the original functionality of the light switch. The rest of the design includes a header for programming the board and another header for tying into the high voltage lines. This is a great project for anyone who knows what they’re doing with mains power but is just getting started with microcontrollers. If properly designed and implemented you’ll never stumble across a room to turn the lights out again!

Perhaps mixing high and low voltages on the same circuit board doesn’t spark your fancy or you can’t modify the light switch in your place of residence? Check out this mechanically-switched light switch.


A Levered Light Switch Even Fido Can Operate

Dog Light

We love hacks that make a difference in people’s lives. Service dogs can make a huge difference in a physically disabled person’s life, and while they can do a lot of things, dogs aren’t the greatest at flipping light switches. So a team of industrial design students from Ghent, Belgium decided to try finding a solution.

Their case study was for a young woman named [Heleen Bartsoen]. She has a very smart white golden retriever named [Gyproc] who is very good at picking up commands, and is a very careful and cautious service dog. She has an IKEA lamp with a foot switch that neither she or her dog can press.

The team quickly got to work and decided to design a lever to give the dog (or Heleen!) some mechanical advantage to actuate the switch. Having access to a laser cutter, they designed the lever to be cut out of plywood for easy assembly. It pivots around a wooden dowel, and they’ve filled a compartment of the base with cement to keep it stationary when being used.

Continue reading “A Levered Light Switch Even Fido Can Operate”

Remote Servo-controlled Lightswitch


We frequently get home automation tips, many of which have simple circuit-based on/off control for lights. [Paulo Borges] has created something quite different, however, with his in-the-wall servo-controlled light switch. This build forgoes the need of any relay to switch mains power, and because it’s physically flipping your switch, provides a distinct advantage over other builds that require a phone or tablet interface: you can use your switches as you normally would.

[Paulo] picked up a rocker-type switch at the local hardware store and carefully pried off the large, flat switch plate to notch out a small hole at its fulcrum. He then carefully shaped a piece of 12 gauge wire to provide a pivot point for the servo. His choice to use wire here seems to be entirely to provide a sturdy yet bendable component that functions mechanically rather than electrically. A small 9G servo fits to the back of the switch’s housing, and the servo’s arm connects up to the previously attached 12 gauge wire. He pieced together the remote control feature with an RF link kit with an inexpensive 433mhz Code duplicator from eBay.

[Paulo] explains that his Instructable is simply an overview rather than a step-by-step guide, so if you’re eager to reproduce this hack you’ll have to work out the code and the remote control portion yourself. He also acknowledges the biggest remaining hurdle: finding space in the wall to shove all the microcontroller guts. Check out a couple of videos of the switch after the break, and remember, there’s always the option of doing away with all light switches.

Continue reading “Remote Servo-controlled Lightswitch”

Dimming the living room lights using your TV remote

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.

Lighting controller counts how many people are in a room

[Deekshith Allamaneni] built this controller which will automatically turn the lights in a room on and off. No big deal, right? You can already get a replacement light switch at the home store that will do this for you. But there is one big difference. The commercial solutions we’ve seen simply rely in a motion sensor and a timer. But [Deekshith] found a way to count the number of people that enter a room, turning the lights on when the first person enters and off when the last person leaves.

The video after the break shows a demo of his test rig. At first we just thought that this was only counting how many times an object passes between the sensors. But it can also detect in which direction that object was traveling. Now the system just needs to be scaled up for use in a doorway.

It would be a great addition to the house that doesn’t have any light switches.

Continue reading “Lighting controller counts how many people are in a room”

[RobB’s] house has no light switches

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.

Continue reading “[RobB’s] house has no light switches”