Monitoring Your Gas Consumption With A JeeNode And A NRF24L01+

March 23, 2014 by Mathieu Stephan 15 Comments

[Sven337] just blogged about a gas consumption monitoring setup he finished not long ago. As his gas meter was located outside his apartment and nowhere near any electrical outlet, a battery-powered platform that could wirelessly send the current consumption data to his Raspberry Pi was required. His final solution therefore consists of a JeeNode coupled with the well known nRF24L01+ wireless transmitter, powered by 3 supposedly dead alkaline batteries.

[Sven337] carefully looked at the different techniques available to read the data from his meter. At first he had thought of using a reflective sensor to detect the number 6 which (in France at least) is designed to reflect light very well. He then finally settled for a magnetic based solution, as the Actaris G4 gas meter has a small depression intended for magnetic sensors. The PCB you see in the picture above therefore has a reed sensor and a debug LED. The four wires go to a plastic enclosure containing the JeeNode, a couple of LEDs and a reset switch. Using another nRF24L01, the Raspberry Pi finally receives the pulse count and reports it to an eeePC which takes care of the storage and graphing.

Prop Replica Tesseract Case Has Some Serious Tech Inside

March 12, 2014 by James Hobson 4 Comments

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[Dustin Evans] is a big fan of the recent Avengers movies — heck, we are too! So he decided to make this awesome Tesseract Case prop replica!

Tesser-what? A tesseract, or cubic prism is a geometric shape that is technically a four-dimensional hypercube — in the Avenger’s movie, it is an incredibly powerful and unstable alien energy source.

To make the replica, [Dustin] picked up a cheap aluminum tool case from the hardware store, took some measurements and began designing the inside of it using SketchUp. He’s crammed in an Arduino with a spectrum shield, a BlueSmirf Bluetooth modem, a Raspberry Pi, a 7″ LCD, speakers and an amp, a WiFi card for the Pi, and a few strips of Neopixels. It is running Raspbian with a stand-alone version of XBMC, which means using AllCast he can wirelessly control the box from a phone or tablet — now all he’s missing is a mini-generator that can put out a few million watts!

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Smart Kegerator Bills Based On Beer Consumption

March 11, 2014 by Kristina Panos 34 Comments

Kegerator ownership is awesome, but it has its downsides. It’s hard to keep track of who drank what without cans or bottles to count. [Phil] was looking for a good solution to this problem when it came to sharing beer with his roommates and friends and has just completed the first iteration of his smart kegerator.

He has devised a system based on a Raspberry Pi. His software recognizes the face of the person pulling a beer and adds a charge to their tab based on the price of the keg and the volume of the pour. The system also keeps track of current and historic temperature and humidity values inside the kegerator, and everything is displayed on a Mimo 720S touch screen.

[Phil] has a flow meter on each keg to detect and monitor pouring. This triggers the Pi camera module to run the facial recognition. The walk-through found after the jump might be a bit confusing; at the time it was recorded, the unit was only capable of facial detection. [Phil] wrote the UI in QT and C++ and used Python scripts for the flow interrupts. His plans for future iterations include weight sensors underneath the kegs, liquid probe thermometers for more accurate beer temperature readings, a NoIR Pi camera module for low light conditions, and a really snazzy UI that you’ll see on his build page.

If you don’t have a Pi, here’s an Arduino-fied kegerator that reports temperature and controls beer cooling.

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Ridiculously Accurate Mission Control Panel

February 27, 2014 by James Hobson 32 Comments

We are absolutely blown away by the level of detail that went into this amazing mission control panel that [Jeff Highsmith] made for his son.

His kid just started school and needed a desk to do homework on. They had recently visited the Kennedy Space Center, and his son found a new interest in all things space — So [Jeff] took the opportunity to make the desk into this mind-boggling control panel.

We saw a similar project recently, but this one seems to take it to the next level. The desk itself is hand-made from MDF sheet and with oak boards making up the structural members. He’s cut out over a dozen individual control panels, added switches, LEDs and potentiometers, and printed the labels on transparencies which give the whole thing a very professional and finished look. An iPad sits in the middle which plays a curated collection of space videos.

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Wireless AC Control With The Raspberry Pi

February 26, 2014 by Brian Benchoff 43 Comments

We’ve seen some of [Connor]’s work before, and it looks like he’s now turning to product design. He’s come up with an adapter for the Raspberry Pi to control a few wireless wall socket relays, allowing anyone with a Pi to control lights, coffee makers, TVs, and anything else that falls under the very broad home automation banner.

The system uses a 315MHz radio breakout board for a Raspberry Pi to control the relays in one of three wall socket adapters. There’s a script running on the Pi with a very nice GUI to turn the lights on and off.

[Connor]’s product is extremely similar to a certain WiFi-enabled wall-plug relay system controlled by a smartphone, and to that end, he’s decided to call his device the Belchin’ Emo Switch. The name might need work, but he’s selling three Raspberry Pi-controlled wall plugs for the same price of one wall plug from Brand A.

Below you’ll find [Connor]’s videos for his device. You can also check out this reddit thread where he shows off just how open source he can be; there are part suppliers and even how he’s packaging this system for shipment.

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Vintage DACs And A Raspberry Pi

February 23, 2014 by Brian Benchoff 25 Comments

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Before the days of iPod docks in every conceivable piece of audio equipment, most devices were actually built very well. Most shelf top equipment usually came with well designed circuits using quality components, and late 90s CD players were no exception. [Mariosis] heard of some very nice DACs found in some of these units and decided to take one out for a spin. He’s using a Raspberry Pi to play audio with the DAC found in a late 90s Kenwood CD player.

After fortune favored a CD player with a dead drive on [Mariosis]’ workbench, he dug up the service manual and found some interesting chips – a PCM56 DAC, a little bit of logic, and an SM5807 oversampling chip that does all the conversion for the DAC.

This oversampling chip uses an I2S – not I2C – bus to carry the data from the CD to the DAC. There is, of course, an I2S driver for the Raspi, but the first attempts at playing audio didn’t result in anything. It turned out there was a problem with what the oversampler expected – the ‘standard’ I2S signal delays the data one tick behind the LRCLK signal.

There are two ways to fix this problem: programming a kernel driver, or building some custom logic to fix the problem. Obviously breaking out some flip-flops and NOR gates was the cooler option, giving [Mariosis] a great sounding stereo with a vintage DAC.

Mobile Hackerspace Status Indicator

February 18, 2014 by James Hobson 16 Comments

HACKERSPACE LIGHT

Cruising around town, not sure what to do — oh hey look, someone is at the hackerspace! Introducing the Mobile Spacestate Indicator!

During our Hackerspacing in Europe tour, we had the pleasure of visiting ACKspace in Heerlen, the Netherlands. And like many hackerspaces, they have an online status indicator letting members and non-members alike know if the space is open. [Vicarious], the gentleman who kindly picked us up from the train station, has just finished off an awesome modification to his car. Using an Arduino Uno and a Raspberry Pi, he has created a mobile indicator of his hackerspace’s status.

The Raspberry Pi automatically tethers to his phone and checks the status of the hackerspace online. It then sends the data to the Arduino Uno which controls a small strip of RGB LEDs. He’s cleverly hidden all of this inside his center console, and it looks awesome!

To see more of ACKspace’s cool projects, check out their wiki!