Before we begin, we must begin with an obligatory disclaimer: handling mains voltage can be very dangerous. Do not do so unless you are qualified! You could burn your house down. (Without the lemons.) That being said, [TJ] has created an interesting dev board for controlling mains voltage over WiFi with the now-ubiquitous ESP8266 module. At only 50mm x 25mm, it is easily small enough to fit inside a junction box!

Called the MPSMv2, the core of the project is the ESP8266 module. The dev board itself can support anything with GPIO pins, whether it’s an Arudino, Raspberry Pi, or anything else with those features. Flashing the NodeMCU firmware is pretty much all that needs to be done in order to get the device up and running, and once you get the device connected to your WiFi you’ll be able to control whatever appliances you want.

The device uses a triac to do the switching, and is optically isolated from mains. Be sure to check out the video after the break to see the device in action. All in all, this could be a great way to get started with home automation, or maybe just do something simple like build a timer for your floor lamp. Anything is possible!

Using an Arduino or Raspberry Pi to perform a task in the real world is certainly a project we’ve seen here before, and certainly most of these projects help to make up the nebulous “Internet of Things” that’s all the rage these days. Once in a while though, a project comes along that really catches our eye, as is the case with [Jamie’s] meticulously documented automatic garage door opener.

This garage door opener uses an ATMega328 to connect the internet to the garage door. A reed switch is installed which lets the device sense the position of the door, which is relayed back to the internet. [Jamie] wrote an Android app that can open and close the door and give the user the information on the door’s status. One really interesting feature is the ability to “crack” the garage door. This is done by triggering the garage door opener twice with a delay in between. From the video after the break we’d say this is how [Jamie’s] cat gets in and out.

We love seeing projects that are extremely well documented so that anyone who wants to make one can easily figure out how. Internet-connected garage door openers have been featured in other unique ways before too, but we’ve also seen ways to automatically open blinds or chicken coops!

We’ve always wondered why we have indoor plumbing if it isn’t hooked up to our coffee pots. We probably drink as much coffee as water anyway, so why not just hook up a water line to refill the pot? [Loose Cannon] aka [LC] has been working on just that problem, with a whole lot of extra features, creating a very robust automatically-filled, gravity-fed, vacuum-sealed water tank for whatever appliance you have that could use it, including your coffee pot.

[LC] tapped into the 1/4″ water line from the ice maker, which has the added bonus of being a common size for solenoid valves. He’s using an eTape sensor to measure the water level in the reservoir, but he ALSO is using a flow meter in the line itself to double-check that the reservoir won’t overflow. The flow meter allows a hard limit to be set for the maximum amount of water allowed into the tank. He’s used an Arduino Micro to tie the project together, which also handles a real-time clock so the tank can be filled on a schedule.

The tank that [LC] was trying to fill was vacuum-sealed as well, which made things a little trickier. Without a vacuum on the tank, the water would just run out of the overflow valve. This is an interesting project that goes way beyond the usual automatic water supplies for coffee pots we’ve seen before.

For most of the Northern Hemisphere, winter is in full swing right now. That means long, chilly nights. We assume [LC] is in one of these climes because it seems like his bed warmer wasn’t doing quite a good enough job of getting his bed up to a reasonable temperature before he climbed in. To alleviate some of his discomfort, he hacked into the control unit and added some automation.

The original controller uses a mechanical potentiometer to set the heat level. [LC] added a digital potentiometer which he can switch to in order to allow the automation (using a real-time clock to handle scheduling) to take over control of the bed warmer. This also preserves the original functionality of the controller. There is also an Arduino involved which handles the override from mechanical to digital potentiometer when a capacitive touch sensor is activated. This means that when someone attempts to take manual control of the device, the Arduino can switch the override circuit off.

There is quite a bit of detail on the project site about this hack, including the source code for the controller. [LC] also mentions that this could be interfaced to the web to allow remote control of the bed warmer. This is a great hack, and also fits into the idea of heating the person, not the room.

We have a pretty good guess where [Krizbleen] hides away any seasonal presents for his family: behind his shiny new secret library door. An experienced woodworker, [Krizbleen] was in the process of finishing the attic in his home when he decided to take advantage of the chimney’s otherwise annoying placement in front of his soon-to-be office. He built a false wall in front of the central chimney obstacle and placed a TV in the middle of the wall (directly in front of the chimney) flanked on either side by a bookcase.

If you touch the secret book or knock out the secret sequence, however, the right-side bookcase slides gently out of the way to reveal [Krizbleen’s] home office. Behind the scenes, a heavy duty linear actuator pushes or pulls the door as necessary, onto which [Krizbleen] expertly mounted the bookcase with some 2″ caster wheels. The actuator expects +24V or -24V to send it moving in one of its two directions, so the Arduino Uno needed a couple of relays to handle the voltage difference.

The effort spent here was immense, but the result is seamless. After borrowing a knock-detection script and hooking up a secondary access button concealed in a book, [Krizbleen] had the secret door he’d always wanted: albeit maybe a bit slow to open and close. You can see a video of its operation below.

When [William’s] thermostat died, he wanted an upgrade. He found a few off-the-shelf Internet enabled thermostats, but they were all very expensive. He knew he could build his own for a fraction of the cost.

The primary unit synchronizes it’s time using NTP. This automatically keeps things up to date and in sync with daylight savings time. There is also a backup real-time clock chip in case the Internet connection is lost. The unit can be controlled via the physical control panel, or via a web interface. The system includes a nifty “vacation mode” that will set the temperature to a cool 60 degrees Fahrenheit while you are away. It will then automatically adjust the temperature to something more comfortable before you return home.

[William’s] home is split into three heat zones. Each zone has its own control panel including an LCD display and simple controls. The zones can be individually configured from either their own control panel or from the central panel. The panels include a DHT22 temperature and humidity sensor, an LCD display, a keypad, and support electronics. This project was clearly well thought out, and includes a host of other small features to make it easy to use.

When the washing machine at [hydronucleus]‘s place went on the fritz, he went straight to the toolbox to try to repair it. The problem was with the old mechanical control unit, so [hydronucleus] got an Arduino out of the parts bin to create a brand new electronic controller for his washing machine. (Imgur Link)

The old mechanical controller functioned like a player piano. A rotating drum with ridges actuate different cycles in the washing machine. Some of the cycles weren’t working properly so [hydronucleus] ripped them out. With the help of a schematic posted on the washing machine itself, the cycles were able to be programmed into the Arduino.

The other obstacle in this repair was getting enough relays together to switch everything in the washing machine. This was solved with a Sainsmart 16 relay block, which has more than enough relays for the job. [hydronucleus] wired up an LCD and a pushbutton to control it and his washing machine is as good as new! The cost of the repair certainly beats a new machine, too. Although if it finally gives up the ghost completely, he could always turn it into a windmill.

Want to read more about [hydronucleus]‘s washing machine hack? Check out his Reddit thread!

We’re no strangers to home automation projects around here, but it’s not often that you see one described in this much detail. [Paul] designed a custom home automation system with four teammates for an undergraduate thesis project.

The system is broken into two main components; the server and the peripherals. The team designed their peripherals from early prototypes of an upcoming ArduIMU v4 measurement unit. They removed all of the default sensors to keep costs down and reduce assembly time. The units can them be hooked up to various peripherals such as temperature sensors, mains relays, RGB color strips, etc.

The central management of the system is performed using a web-based user interface. The web server runs on Java, and interacts with the peripherals wirelessly. Basic messages can be sent back and forth to either read the state of the peripherals or to change the state. As far as the user is concerned, these messages appear as simple triggers and actions. This makes it very simple to program the peripherals using if, then, else logic.

The main project page is a very brief summary of what appears to be a very well documented project. The team has made available their 182 page final report (pdf), which goes into the nitty-gritty details of the project. Also, be sure to watch the demonstration video below.

Fans of the bouncing lamp from the Pixar corporate logo will enjoy [Daniel]‘s latest project. It’s a motion controlled desk lamp that uses ultrasonic sensors to control its physical position.

The core of the project is an Arduino and the three ultrasonic sensors. The sensors act as range finders, and when they are all working together under the direction of the microcontroller they can tell which direction a hand was moving when it passed by. This information is used to drive two servos, one in the base and one on the lamp’s arm.

The project requires an articulating desk lamp of some sort (others besides the specific one [Daniel] used shouldn’t be much of a problem as long as they bend in the same way). Most hackers will have the rest of the parts on hand, with the possible exception of the rangefinder. The code is up on the project site for a look-see or in case you want to build your own.

The only problem that [Daniel] had when putting this all together was that the base was a little wobbly. He was able to fix that with some thumbtacks, and we think the next step for the project should be switching the light on and off over the internet.

With the severe drought going on in California with no end in sight, [TVMiller] decided he could put an Arduino and a toilet together to try and save at least a few gallons of water per day. The invention fills a toilet to the minimum level, saving around two gallons per day for the average “user”.

A typical toilet functions by using gravity and moving water to create a vacuum, sucking the waste down and out of the toilet. As long as there is nothing, uh, solid in the bowl, the toilet will be able to function on the reduced amount of water. The Arduino cuts the flow of water off before the toilet fills up the entire way.

In the event that anyone -ahem- needs the toilet’s full capacity, there is a button connected to the Arduino that fills the reservoir to capacity. [TVMiller] notes that if 1,825 hackers installed this device on their toilets, we could save a million gallons of water per year and be well on our way to saving the planet.

The project site is full of more information and puns for your viewing pleasure. We might suggest that the “2” button would be very easy to integrate with the toilet terror level indicator as well.