home hacks

1867 Articles

Control board for a Wi-Fi enabled thermostat

Controlling Central Heating Via Wi-Fi

February 27, 2015 by 11 Comments

If you’ve ever lived in a building with manually controlled central heating, you’ll probably understand [Martin]’s motivation for this hack. These heating systems often have old fashioned valves to control the radiator. No Nest support, no thermostat, just a knob you turn.

To solve this problem, [Martin] built a Wi-Fi enabled thermostat. This impressive build brings together a custom PCB based on the ESP8266 Wi-Fi microcontroller and a mobile-friendly web UI based on the Open Thermostat Scheduler. The project’s web server is fully self-contained on the ESP8266.

To replace that manual value, [Martin] used a thermoelectric actuator from a Swiss company called HERZ. This is driven by a relay, which is controlled by the ESP8266 microcontroller. Based on the schedule and the measured temperature, the actuator lets fluid flow through the radiator and heat the room.

As a bonus, the device supports NTP for getting the time, MQTT for publishing real-time data, and ThingSpeak for logging and graphing historic data. The source code and design files are available under a Creative Commons license.

A protoboard layout for an ATtiny85 door chime

AES-CMAC On An ATtiny85

February 20, 2015 by 35 Comments

[Blancmange] built a custom door chime using an ATtiny85. Unlike most commercial products out there, this one actually tries to be secure, using AES-CMAC for message signing.

The hardware is pretty simple, and a protoboard layout is shown in the image above. It uses the ATtiny85 for control, with an LM380N audio amplifier, and a low cost 315 MHz receiver.

The more impressive part of the build is the firmware. Using AVR assembly, [Blancmange] managed to fit everything into the 8 Kbytes of flash on the ATtiny85. This includes an implementation of AES-CMAC, an AES cypher based message authentication code. The transmitting device signs the request with a key shared between both devices, and the receiver verifies that the message is from a trusted transmitter.

Fortunately, the assembly code is very well commented. If you’ve ever wanted to take a look into some complex ASM assembly, this is a great project to check out. The source code has been released into the public domain, so the rest of us can implement crypto on this cheap microcontroller with much less effort.

Automatic Garage Door Opener Works For Your Cat

February 17, 2015 by 14 Comments

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!

RasPi Garage Door

A Raspberry Pi Garage Door Opener

February 15, 2015 by 32 Comments

We can never seem to get enough garage door hacks around here. [Tanner’s] project is the most recent entry into this category. He’s managed to hook up a Raspberry Pi to his garage door opener. This greatly extends his range to… well anywhere with an Internet connection.

His hack is relatively simple. He started with the garage door opener remote. He removed the momentary switch that was normally used to active the door. He bridged the electrical connection to create a circuit that was always closed. This meant that as long as the remote had power, the switch would be activated. Now all [Tanner] had to do was remove the battery and hook up the power connectors to his Raspberry Pi. Since the remote works on 3.3V and draws little current, he is able to power the remote directly from the Pi. The Pi just has to turn its pin high momentarily to activate the remote.

The ability to toggle the state of your garage door from anywhere in the world also comes with paranoia. [Tanner] wanted to be able to tell if the door is up, down, or stopped somewhere in the middle while he was away from home. He also wanted to use as little equipment as possible. Since he already had an IP camera in the garage, he decided to use computer vision to do the detection.

He printed off two large, black shapes onto ordinary white computer paper. One was taped to the top of the door and one to the bottom. A custom script runs on the Pi that grabs the latest image from the camera and uses OpenCV to detect the shapes. If both shapes are visible, then the script can assume the door is closed. Otherwise, it’s likely open. This makes it easier for [Tanner] to know if the door is opened or closed without having to check the camera himself.

Can’t get enough garage door hacks? Try these on for size. Continue reading “A Raspberry Pi Garage Door Opener” →

IOT Lightbulb hack

Repurposing IOT Lightbulb Chip For Anything

February 15, 2015 by 27 Comments

Home automation products have hit critical mass in the world of consumerism, and now suddenly everyone has a product you can control using some protocol or other. Cree (the maker of LEDs) has a rather cheap IOT-enabled bulb available in Canada and the US for the low price of $15 — not bad considering regular LED bulbs can run you that much, without wireless connectivity!

So if you want to outfit your house in smart lights — great. But what about other things? Well, [Mac Alpine] decided to crack open one of the bulbs to see if he could re-purpose the IOT board. Turns out, you can.

In fact it’s almost too convenient. It’s a remarkably small chip, about half the size of a silver dollar. And it features a small ZigBee radio module. All you need is a 3V power supply, and boom — you have an IOT module that is capable of PWM output. It features an Atmel ATSAMR21E microprocessor which communicates over the radio to a Quirky Wink hub — it can also be triggered using IFTTT.

Continue reading “Repurposing IOT Lightbulb Chip For Anything” →

Climbing Wall in Garage

Rock Climbing Wall Installed In Garage Doubles As Storage Space

February 14, 2015 by 8 Comments

Climbing enthusiast and human spider [Swighton] just couldn’t get enough climbing crammed into his day. If he couldn’t get out to the climbing spots, why not bring the climbing spot to him? So he did that by building a climbing wall in his garage.

The process started with determining the available space that can be allocated to the project. In [Swighton]’s case he could afford an 8×12 ft section of real estate. The garage ceilings were 8 ft high. A few days were spent sketching out ideas and designs. To suit his needs, the wall had to have a 45 degree overhang section, a small 90 section (think ceiling, not wall) and a pull-up bar. Once the design was finalized, it was time to pull some sheet rock off the walls and ceiling so that the 2×4 and 2×6 climbing wall framing could be securely fastened to the current garage structure.

Three-quarter inch plywood would cover the wooden frame. Before the plywood sheets were cut to size and installed, he drilled holes every 8 inches to accept t-nuts. These t-nuts allow hand holds to be installed and easily reconfigured. The quantity of t-nuts adds up quickly, an 8 inch square spacing results in 72 t-nuts per sheet of plywood.

[Swighton] also added a hatch to allow access to the inside of the climbing wall so that space would not go to waste. It is now a storage area but may become a kids’ fort in the future. After it was all said and done the wall only cost $400 which includes $180 for the hand holds.

If you’re like [Swighton] and can’t get enough climbing action, check out this wall with light up hand holds or this interactive wall.

Ridiculously Complicated Home Automation Made Simple

February 12, 2015 by 33 Comments

[Eric T] wrote up his insanely-comprehensive home automation setup. What started out as a method to notify him when his dog barked grew into a whole-house, Arduino-powered sensor extravaganza. We’ve previously looked at two different steps from this mammoth article. One automated his dog, the other focused on the Wink hub to bridge with commercial hardware like smart lightbulbs. Now let’s look at the project as a whole.

The basic backbone of the project is actually quite straightforward. He made a radio gateway base station out of an Arduino, a RFM69 radio unit, and an Ethernet shield that connects to a Raspberry Pi to serve up a GUI interface. The open-source home automation project OpenHAB makes it all available through browser or smartphone.

Next, he made additional sensor nodes from Arduino and RMF69 radios. These sensor nodes can all be separate from each other, which has enabled [Eric] to expand his system incrementally over time.

Modules of particular interest are the Uber Sensor and the Washer-Dryer module. For the Uber Sensor, [Eric] basically threw every sensor he could at an Arduino; it sends noise levels, light levels, motion, temperature, humidity, and presence of smoke, flame, or flammable gas. Some of these conditions trigger e-mail alerts, while others are simply stored for future perusal.

On the simpler end of the spectrum, he uses a noise-level detector to detect the end of a laundry cycle and then trigger a notification. The clever bit is that the message is automatically cleared when an attached motion detector triggers, presumably because someone’s gone to the basement to empty the dryer. Very neat.

16All of this is basically made practical and affordable by the presence of simple Arduino libraries and cheap hardware modules purchasable over Ebay. If you’re at all interested in a DIY home automation project, this offering is worth a look for inspiration and a great overview.