Personal Energy Orb Prevents Your Life From Being Swallowed By The Internets

September 25, 2012 by Mike Szczys 14 Comments

We love the Internet, but we are definitely guilty of losing track of the time we spend traipsing around our virtual haunts. This project will not only remind you to get out and exercise, it will cripple your digital experience if you don’t heed its colorful warning.

[Janko Hofmann] calls it the Personal Energy Orb. It’s really just an Arduino and an RGB LED. But as with most creations, the idea is what makes it great. The orb has a dock next to your computer. It tracks how much time you spend online, changing colors as you rack up the hours. If you don’t heed the warning signs of overuse it will even start to slow down your mouse cursor. But never fear. Full functionality can be restored by topping off your personal energy. As you can see above, there’s also a docking station on [Janko’s] bicycle. The orb monitors your mileage, moving out of the red zone so that your computer will be unencumbered the next time you sit down for a long session of flash games. Don’t miss his video presentation embedded after the break.

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Tutorial Explains The Concepts Behind An IMU

September 25, 2012 by Mike Szczys 12 Comments

[Anilm3] wrote in to share the IMU tutorial series he is working on. An Inertial Measurement Unit is most often found in self-balancing robots and quadcopters, providing enough high-speed sensor data to keep up with the effects of gravity. He previously used some all-in-one IMU devices in school which did most of the work for him. But he wanted to grind down and look at what each sensor spits out and how those measurements are used. The first installment deals with the accelerometer, using its data to calculate pitch and roll. For these demonstrations [Anilm3] is using this ADXL345 sensor board, an Arduino, and some processing sketches for testing.

Whenever working with sensors you need to take noise into consideration. The post shows how to implement a low-pass filter in the code which will help smooth out the readings. The filtered data is then fed to a couple of mostly-painless formulas which calculate the movement of the accelerometer in degrees. The demonstration sketch is mapped to a 3D cube to give you an idea of how accurate the accelerometer is. There’s a little bit of lag which would let a self-balancing robot have a nasty fall. The solution to this issue will be discussed in upcoming parts of the series. The next installment tackles the gyroscope sensor.

Speech Recognition On An Arduino

September 22, 2012 by Brian Benchoff 33 Comments

Speech recognition is usually the purview of fairly high-powered computers chugging along at hundreds of Megahertz with megabytes of RAM. Bringing speech recognition to the low-power microcontroller you’d find in an Arduino sounds like the work of a mad scientist or Ph.D. candidate, but that’s exactly what [Arjo Chakravarty] did. He developed the μSpeech library for the Arduino to allow for speech recognition for a limited set of voice commands.

Where most speech recognition systems use FFT and very fancy math to determine what phonemes a user is saying, [Arjo]’s system does away with this unnecessary complexity in favor of using very, very basic integral and differential calculus.

From [Arjo]’s user guide for μSpeech (PDF warning) we can see it’s possible to connect a small microphone to the analog input of an Arduino and accept voice commands such as ‘left’, ‘right’, and ‘stop’. The accuracy is pretty good, as well – 80% if μSpeech is trying to recognize words, and 30-40% if μSpeech is programmed to recognize single phonemes.

Sadly we couldn’t find a demo video of μSpeech in action, but you’re more than welcome to grab it via github for your own project. Send us a video of μSpeech in action and we’ll put it up.

Wiring Up A Lot Of LED Segment Displays

September 21, 2012 by Mike Szczys 16 Comments

One look at this display and you know there’s a whole lot of pins that need to be wired up. Now look at what those display modules are mounted on. That’s right, [Kemley] is using point-to-point soldering to rig up this big display. It sports four sixteen segment modules on top for alpha-numeric information, and eight large seven segment modules for displaying numbers only.

We’re not certain as to how the electronics are arranged. When talking about the 16-segment modules he mentions that all four are in parallel with NPN transistors to switch the common anode of each. That’s easy enough to understand. But when you get a look at the transistor board you’ll see 24 of them in use. He’s included a 150 ohm resistor on the collector of each transistor. It must be set up to only allow one segment of each group to switch on at a time? We’d guess that each segment is divided into two (upper and lower pins are multiplexed separately), which would explain the double set of transistors. As for date and time, an Arduino board monitors a DS1307 RTC and manages the scanning of the display.

Tuitwall Uses PHP-fed Arduino To Display Tweets

September 18, 2012 by Mike Szczys 4 Comments

[Santiago] recently completed this project which he calls Tuitwall. It will display your Twitter feed on an LED matrix. The method he used to put it together will come in handy for any project where you need to scrape information from the Internet.

The project does require a server in addition to the Arduino hardware seen above. On the Arduino side [Santiago] uses an Ethernet shield and an LED matrix which is addressed via SPI. The server is running a PHP script which takes advantage of the twitteroauth library to handle authentication.

There’s a little bit of configuration to be done, most of it having to do with how Twitter handles 3rd party applications. But once everything is set up you can take the hardware with you and plug it into any network (as long as it offers DHCP). With this framework as a guide it’s a snap to bend it to your will. It could be used as an RSS reader, time and temperature, server farm status, a prank ticket displaying fake headlines, etc.

Scrolling Tweets With A WiFi LED Matrix

September 17, 2012 by Brian Benchoff 4 Comments

For his most ambitious build to date, [Param] thought it would be a cool idea to have a LED matrix display spitting tweets out via a WiFi connection. The build is now done, and we’ve got to hand it to him for a very nice build.

The build is based on an Arduino with a Sparkfun WiFi shield providing the network connection. The Arduino pings a Javascript app that pulls down tweets from The Verge and displays them on an 8×8 LED matrix display.

What makes [Param]’s build so cool is its portable nature; the entire device is completely wireless, getting its power from a Sparkfun LiPower shield and an apparently extremely capacious LiPoly battery.

With a rat’s nest of wires hanging out the back of the LED display, [Param]’s build is crying out for a proper enclosure, but even given that it remains a quality project. You can see a video of the WiFi’d Twitter display after the break.

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RC Car Upgraded To Bluetooth Control

September 14, 2012 by Mike Szczys 7 Comments

[Chet] is showing off the Bluetooth controller upgrade for this RC car. The donor vehicle is a rather inexpensive Porche which he purchased to make sure he didn’t start hacking up his more expensive toys.

He took a bit different route than the IOIO RC truck we saw earlier in the week, but the concept is basically the same. That build used an IOIO board with a USB Bluetooth dongle. This one uses an Arduino Mini with a serial Bluetooth module. He patched into the motor driver circuits on the original PCB. While he was at it he also soldered in some LEDs to use as switchable headlights.

There was one issue which he had to overcome. The current draw from the motor starting up would sometimes dip the voltage low enough to reset the Arduino. He tried using a bigger capacitor to feed the board, but in the end opted to add a boost converter.