Digital Data From A Cheap Power Meter

October 21, 2014 by Ethan Zonca 46 Comments

Power meters like the Kill-A-Watt are great for keeping track of energy usage, and are also very hackable. The Kill-a-Watt in particular puts out analog signals proportional to current and voltage, which makes it easy to interface with a microcontroller.

Although reading analog voltages is easy enough, [Kalle] found a cheap Chinese power meter that is even more hackable. These inexpensive power meters cost about the same as a first-generation Kill-a-Watt, but they directly stream out digital data. The power meter [Kalle] hacked has a non-US plug, but the meter is available from the usual suppliers (eBay, Aliexpress, etc) with a 3-prong US plug and 120v rating.

After breaking out a logic analyzer, [Kalle] discovered that the meter constantly streams voltage, current, and power data from the measurement board to the display board on a SPI-like bus. The ribbon cable inside the meter even has the clock and data bus lines clearly labelled. [Kalle] went on to reverse-engineer the protocol and write an Arduino sketch that parses the stream, making it even easier to integrate this meter into your next power monitoring project.

DIY Auto Fish Feeder Feeds Fish Automatically

October 14, 2014 by Rich Bremer 28 Comments

[Brian] has a fairly large 400 liter aquarium and loves the fish that call it home. Unfortunately, sometimes life gets in the way of keeping those fish fed on a regular basis. There are automatic fish feeders out there on the market and [Brian] gave one a try. Although it worked, it dropped one huge clump of food in at a time (rather than sprinkling it in), the food hopper held a very small amount of food and the unit drained a new set of batteries in less than a week. Fifty euros were spent on purchasing that auto feeder and in the end it wasn’t any more convenient than just feeding the fish.

Faced with a tough decision on whether or not to buy another product he may not be happy with, [Brian] decided to make his own automatic fish feeder system out of parts anyone can find lying around the house. The main housing is a small Tupperware bin, inside of which 3 pieces of plastic were glued together to make a v-shaped hopper. The fish food is loaded into the hopper and as it falls to the bottom it meets a reverse-spinning drill bit that acts like an auger, pushing the food out of the container. The drill bit is powered by a small stepper motor connected to the drill bit by an improvised coupling made from a silicone sealant cap!

The control system is an Arduino and a stepper motor driver chip. Through trial and error [Brian] figured out that 100,000 half steps of the motor dumped a good amount of food into the tank. The drill bit delivery method even sprinkles the food nicely for total fish enjoyment. To keep the food flowing at regular intervals, an AC timer unit controls how often the Arduino is powered on and subsequently feeds the fish.

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New Brain For An Old Washing Machine

October 14, 2014 by Bryan Cockfield 65 Comments

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!

College Dorm Transforms Into High Tech Office

October 12, 2014 by James Hobson 24 Comments

College dorms are notoriously tiny; which either forces most students into a life of minimalism, or for [Thomas Hopmans], innovation to overcome the lack of square-footage.

His first step was getting a Murphy bed, which saves tons of space. But he wanted to add a few extra features to his, so instead he decided to make his own! He designed the entire thing in SolidWorks, which might seem like overkill, but he’s an Industrial Design student, and has become quite proficient in the software from his various work internships.

The bed uses pneumatic struts to make lifting and lowering the bed frame easy — the cool part is the mechanism he designed which causes his dual 28″ monitors to pop up from the desk. They’re directly coupled to the bed with a linkage which ensures they’ll never get accidentally crushed by the bed.

He admits he could have just mounted the monitors to the bottom of the bed, but that wouldn’t have been nearly as fun as this. He estimates the total cost was around $350 for whole thing, which isn’t half bad for a bed… and a desk!

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Home Automation With A Custom Wireless Sensor Network

October 11, 2014 by Rick Osgood 5 Comments

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. Continue reading “Home Automation With A Custom Wireless Sensor Network” →

Delta Coffee-Brewing Bot

October 9, 2014 by Ethan Zonca 8 Comments

Pour-over coffee brewing is a simple and cheap hands-on alternative to using an automatic coffee maker. Although coffee aficionados often choose pour-over just for the manual brewing experience, this didn’t stop [Elias] from automating his pour-over coffee setup with an elaborate delta-robot: the DeBrew.

The coffee-brewing robot is built around a delta assembly from a 3d printer controlled by a BeagleBone Black. The BeagleBone drives stepper motors, displays information on a small open-source hardware HDMI LCD display, and serves up a web interface to control the machine. The radius of the pouring pattern, water temperature, and grind coarseness of the DeBrew can all be customized though its web interface.

For those who want to build their own pour-over robot, [Elias] has made a SketchUp drawing of the design and all of his Python source code available as open-source. Check out the video after the break where [Elias] explains how his delta pour-over bot works.

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Twittering Chicken Coops, Batman!

October 6, 2014 by Elliot Williams 5 Comments

By now you’ve seen almost anything Tweet. But have you seen the (French) twittering chicken coop? (Google translate link) [Hugo] had kept two chickens as part of a household-waste reduction campaign, and then afterward started work.

Even if you don’t read French, the chickens’ twitter feed basically tells the story.

The setup can take IR photographs of sleeping chickens and notify [Hugo] when it’s time to collect the eggs. Naturally, an abundance of other sensors are available. The coop can tweet based on ambient temperature, nest temperature, light level, motion sensor status, or the amount of remaining chicken feed. You can easily follow whether the two fowl are in the coop or out in the yard. It’s like Big Brother, only for birds.

The application is, frankly, ridiculous. But if you’re into home (or coop) automation, there’s a lot to be learned and the project is very well documented. [Hugo] used OpenCV for visual egg detection, and custom Python code to slightly randomize the tweets’ text. All of these details are up on his Github account.

And if you just can’t get enough chicken-coop hacks, be sure to check out this mobile chicken coop, this coop in the shape of a golden spiral, or this Bluetooth-enabled, talking chicken coop, among others. You’d think our name was Coop-a-Day.