THP Entry: Cut Energy Consumption By 30 Percent With This WiFi XBee Setup

July 23, 2014 by Matt Terndrup 11 Comments

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Let’s be honest. Paying electricity bills sucks. The amount paid is always too much, and the temperatures in the building are rarely set at a comfortable level. But now, with the help of this DIY Climate Control system, power-users can finally rejoice knowing that the heating and cooling process of their home (or commercial space) can be easily controlled through the utilization of an XBee Remote Kit and a process called zoning.

The team behind the project is [Doug], [Benjamin] and [Lucas]. They hope to solve the inconsistent temperature problems, which are caused by a moving sun, by open-sourcing their work into the community.

Their XBee system runs on a mesh network making it a perfect tool for sensing and communicating which areas in the house are too hot or too cold. Once the data is collected, XBee modules route the information wirelessly to each other until it reaches a central Arduino gatekeeper; which then decides if it wants to heat, ventilate, or air condition the room.

Not to mention all the added benefits posted below:

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POV Display Does It On The Cheap

July 23, 2014 by Adam Fabio 15 Comments

[Sholto] hacked together this ultra low-budget spinning display. He calls it a zoetrope, but we think it’s actually an LED based Persistence Of Vision (POV) affair. We’ve seen plenty of POV devices in the past, but this one proves that a hack doesn’t have to be expensive or pretty to work!

The major parts of the POV display were things that [Sholto] had lying around. A couple of candy tins, a simple brushed hobby motor, an Arduino Pro Mini, 7 green LEDs, and an old hall effect sensor were all that were required. Fancy displays might use commercial slip rings to transfer power, but [Sholto] made it work on the cheap!

The two tins provide a base for the display and the negative supply for the Arduino. The tins are soldered together and insulated from the motor, which is hot glued into the lower tin. A paper clip contacts the inside of the lid, making the entire assembly a slip ring for the negative side of the Arduino’s power supply. Some copper braid rubbing on the motor’s metal case forms the positive side.

[Sholto] chose his resistors to slightly overdrive his green LEDs. This makes the display appear brighter in POV use. During normal operation, the LEDs won’t be driven long enough to cause damage. If the software locks up with LEDs on though, all bets are off!

[Sholto] includes software for a pretty darn cool looking “saw wave” demo, and a simple numeric display. With a bit more work this could make a pretty cool POV clock, at least for as long as the motor brushes hold up!

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Printing Text With A Chart Recorder

July 20, 2014 by Eric Evenchick 6 Comments

Chart recorders are vintage devices that were used to plot analog values on paper. They’re similar to old seismometers which plot seismic waves from earthquakes. The device has a heated pen which moves across a piece of thermally sensitive paper. This paper is fed through the machine at a specified rate, which gives two dimensions of plotting.

[Marv] ended up getting a couple of discontinued chart recorders and figured out the interface. Five parallel signals control the feed rate of the paper, and an analog voltage controls the pen location. The next logical step was to hook up an Arduino to control the plotter.

However, once the device could plot analog values, [Marv] quickly looked for a new challenge. He wanted to write characters and bitmaps using the device, but this would require non-continuous lines. By adding a solenoid to lift the pen, he built a chart recorder printer.

After the break, check out a video of the chart recorder doing something it was never intended to do. If you happen to have one of these chart recorders, [Marv] included all of the code in his writeup to help you build your own.

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Long Range Wireless Sensors For The Home-Area-Network

July 19, 2014 by Matt Terndrup 16 Comments

7785441404784533190 In the near future, we will all reside in households that contain hundreds of little devices intertwingled together with an easily connectable and controllable network of sensors. For years, projects have been appearing all around the world, like this wireless sensor system that anyone can build.

[Eric] hopes his work will help bring the truly expansive Home-Area-Network (HAN) into fruition by letting developers build cheap, battery-powered, long-range wireless sensors. His method integrates with the pluggable OSGI architecture and home automation platform openHAB along with using an Arduino as the lower power, sensor node that is capable of utilizing many types of cheap sensors found online.

[Eric]’s tutorial depicts a few examples of the possibilities of these open-source platforms. For instance, he shows what he calls a ‘Mailbox Sentinel’ which is a battery-powered mail monitoring device that uses a Raspberry Pi to play the infamous, and ancient AOL sound bite “you’ve got mail.” It will also send an email once the postman cometh.

In addition, he lists other ideas such as a baby monitoring sentinel, a washer/dryer notification system, water leak detectors, and security implementations that blast a loud alarm if someone tries to break in. All of this potential for just around $20.

The key to making this project work, as [Eric] states, is the MQTT binding that ties together the Ardiuno and openHAB platform. This allows for simple messages to be sent over the Ethernet connection which is often found in IoT devices.

So all you developers out there go home and start thinking of what could be connected next! Because with this system, all you need is a couple of ten-spots and an internet plug, and you have yourself a strong foundation to build on top of. The rest is up to you.

This open, connected device is [Eric’s] entry for The Hackaday Prize. You can see his video demo after the break. We hope this inspires you to submit your own project to the contest!

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Quick And Dirty RFID Door Locks Clean Up Nice

July 18, 2014 by Marsh 13 Comments

homemade RFID Door Locks

[Shawn] recently overhauled his access control by fitting the doors with some RFID readers. Though the building already had electronic switches in place, unlocking the doors required mashing an aging keypad or pestering someone in an adjacent office to press a button to unlock them for you. [Shawn] tapped into that system by running some wires up into the attic and connecting them to one of two control boxes, each with an ATMega328 inside. Everything functions as you would expect: presenting the right RFID card to the wall-mounted reader sends a signal to the microcontroller, which clicks an accompanying relay that drives the locks.

You may recall [Shawn’s] RFID phone tag hack from last month; the addition of the readers is the second act of the project. If you’re looking to recreate this build, you shouldn’t have any trouble sourcing the same Parallax readers or building out your own Arduino on a stick, either. Check out a quick walkthrough video after the jump.

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Solar Powered DIY Plant Watering System

July 16, 2014 by Rick Osgood 31 Comments

Solar Powered Watering System

It’s great having fresh vegetables just a few steps away from the kitchen, but it takes work to keep those plants healthy. [Pierre] found this out the hard way after returning from vacation to find his tomato plant withering away. He decided to put an end to this problem by building his own solar-powered plant watering system (page in French, Google translation).

An Arduino serves as the brain of the system. It’s programmed to check a photo resistor every ten minutes. At 8:30PM, the Arduino will decide how much to water the plants based on the amount of sunlight it detected throughout the day. This allows the system to water the plants just the right amount. The watering is performed by triggering a 5V relay, which switches on a swimming pool pump.

[Pierre] obviously wanted a “green” green house, so he is powering the system using sunlight. A 55 watt solar panel recharges a 12V lead acid battery. The power from the battery is stepped down to the appropriate 5V required for the Arduino. Now [Pierre] can power his watering system from the very same energy source that his plants use to grow.

The Rabbit H1 Is A Stationary Mouse Replacement

July 4, 2014 by Rick Osgood 6 Comments

rabbit h1

[Dave] has some big plans to build himself a 1980’s style computer. Most of the time, large-scale projects can be made easier by breaking them down into their smaller components. [Dave] decided to start his project by designing and constructing a custom controller for his future computer. He calls it the Rabbit H1.

[Dave] was inspired by the HOTAS throttle control system, which is commonly used in aviation. The basic idea behind HOTAS is that the pilot has a bunch of controls built right into the throttle stick. This way, the pilot doesn’t ever have to remove his hand from the throttle. [Dave] took this basic concept and ran with it.

He first designed a simple controller shape in OpenSCAD and printed it out on his 3D printer. He tested it out in his hand and realized that it didn’t feel quite right. The second try was more narrow at the top, resulting in a triangular shape. [Dave] then found the most comfortable position for his fingers and marked the piece with a marker. Finally, he measured out all of the markings and transferred them into OpenSCAD to perfect his design.

[Dave] had some fun with OpenSCAD, designing various hinges and plywood inlays for all of the buttons. Lucky for [Dave], both the 3D printer software as well as the CNC router software accept STL files. This meant that he was able to design both parts together in one program and use the output for both machines.

With the physical controller out of the way, it was time to work on the electronics. [Dave] bought a couple of joysticks from Adafruit, as well as a couple of push buttons. One of the joysticks controls the mouse cursor. The other joystick controls scrolling vertically and horizontally, and includes a push button for left-click. The two buttons are used for middle and right-click. All of these inputs are read by a Teensy Arduino. The Teensy is compact and easily capable of emulating a USB mouse, which makes it perfect for this job.

[Dave] has published his designs on Thingiverse if you would like to try to build one of these yourself.