Roomba Used To Map Indoor Air Quality

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The next time you set off for a long day in the coal mines, forget the canary – bring your Roomba along instead!

While we are pretty sure that canaries are no longer used in the mining industry, this Roomba hack could make a suitable replacement if they were. A team from the Public Laboratory for Open Technology and Science (PLOTS) recently showed off a Roomba which they modified to test an area’s air quality. Using an Arduino and a volatile organic chemical (VOC) detecting air quality sensor, the Roomba goes about its normal business, lighting an LED any time it encounters overly contaminated air. When captured via a long exposure image, the process creates a “bad air” map of sorts, with the polluted areas highlighted by the glow of the LED.

While the Roomba currently only detects VOCs, the team plans on adding additional sensors in the near future to expand its functionality. The Roomba is merely a proof of concept at the moment, but we imagine that similar technology will be adapted for use in unmanned explorations of chemically hostile environments, if that hasn’t happened already.

[via DVice] [Image via TechnologyReview]

Output Up To 768 PWM Signals From One Arduino

Here’s an Arduino library that will let you drive a very large number of LEDs. [Elco Jacobs], an electrical engineering student, is the author of the library. He has a work-study job that has him helping out others with their electrical projects and he was constantly being solicited for methods to control droves of light emitting diodes. This was the motivation that led him to produce the dazzling 16 RGB LED example seen in the video after the break.

His setup doesn’t use expensive LED drivers, but instead utilizes 595 shift registers which are both common and cheap. He calculates that it is possible to control up to 96 of these shift registers, each driving 8 LEDs, with reasonably satisfying results. This is thanks to his well-optimized code that manages to drive the clock pin of the registers at 1.33 MHz. This optimization is done by writing each command in assembly, which allows him to precisely count the cycles. Each individual pin takes 12-13 cycles to address, totally 9984 cycles at worst when addressing the maximum number of outputs.

[Elco] thinks this is as fast as he can make the routine run, but he is asking for help with testing. If you think you know how to squeeze out a few more cycles, make sure you join in on his forum thread.

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Beat707 LE: A Button Pad-based Standalone MIDI Sequencer

sparkfun_button_pad_midi_controller

[Guilherme] picked up a SparkFun Button Pad and was taking a closer look at the device when he noticed that it was based off the ATMega328 microcontroller. Since he loves working with MIDI, he thought that the Button Pad would make a slick yet compact standalone MIDI controller.

Since his ultimate goal was to create a completely standalone controller aside from the power plug and MIDI interface, it forced him to work quite closely with the ATMega chip. He and his partners spent a good deal of time working through some serial communications issues so as not to block the LEDs or MIDI block timer during operation. Ensuring that the Arduino doesn’t block any other functions is obviously important when you are building a MIDI timer, and it seems [Guilherme] was successful in his quest.

The MIDI controller works quite nicely as you can see in the videos below, great job!

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Chilean Teen Builds Automatic Earthquake Alarm

chilean_teen_earthquake_alarm

When an earthquake is about to strike in Chile, who do you think is first to sound the alarm? You might be surprised that it’s not the government, but rather a 14 year old boy.

After living through an earthquake in 2010 and seeing the devastation this spring in Japan, Chilean teenager [Sebastian Alegria] decided that he wanted to construct something similar to Japan’s earthquake warning system. He purchased an off the shelf earthquake detector for less than $100, and connected it to his computer via an Arduino.

Now, whenever seismic activity is detected, his sensor tweets an alert letting his 29,000+ followers know that a perceptible earthquake is 5 to 30 seconds away. Apparently the Chilean government is working on a similar system that is still at least a year away, so in the meantime his fellow citizens rely on [Sebastian] instead.

While it might seem like a relatively easy hack to pull off compared to other earthquake detectors, we’re impressed by [Sebastian’s] creativity, and his will to help others. He’s been pounding away at computers since he was about 4 years old and has several other popular Twitter-based projects under his belt already, so we won’t be surprised if we hear from him again in the future.

word_clouds_from_broacast_television

Analyzing TV’s Talking Heads With Processing

[Michael] from Nootropic Design wrote in to share an interesting and fun project he put together using one of the products his company sells. The gadget in question is their “Video Experimenter” shield which was designed for the Arduino. It is typically used to allow the manipulation of composite video streams via overlays and the like, but it can also serve as a video analyzer as well.

When used for video analysis, the board lets you decode closed captioning data, which is exactly what [Michael] did here. He decided it would be fun to scrape the closed captioning information from various shows and commercials to do a little bit of content analysis.

Using a Processing sketch on his Arduino, he reads the closed captioning feed from his cable box, keeping a count of every word mentioned in the broadcast. As the show progresses, his sketch dynamically constructs a cloud that shows the most commonly used words in the video feed.

The results he gets are quite interesting, especially when he watches the nightly news, or some other broadcast with a specific target audience. We think it would be cool to run this application during a political debate or perhaps during a Hollywood awards ceremony to discover which set of speakers is the most vapid.

if you’re interested in learning more about the decoding process, [Michael] has put together a detailed explanation of how the closed captioning data can be pulled from a video stream. For those of you who just want to see the decoder in action, keep reading to see a quick video demonstration.

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IPhone To Arduino Communications Sans Jailbreak

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When Google released their ADK allowing Android smart phones to interact with Arduino-based devices, we’re sure there were at least one or two iPhone users who felt left out. Thanks to the folks over at Redpark, those people can now interact with an Arduino without having to jailbreak their phone.

For anyone looking to do any sort of iPhone/Arduino interaction, this is a good thing – except for the price. The 30-pin to serial cable is currently available over at Make for $59, which honestly seems pretty steep to us. When we first saw this announced, our initial thoughts were that we would see an open-source version in no time.

Unfortunately, that idea was short-lived, as we were quickly reminded of Apple’s MFI program. If you are not familiar, MFI (aka Made for iStuff) program limits what can be connected to an iDevice via licensing fees and a boatload of legal agreements. While we won’t be picking up this dongle any time soon, we’re all ears if someone has done any reverse-engineering of those pesky MFI chips.

DIY Robot Remote Control

[Patrick] wanted a remote control to control some of the robots he’s built. He also wanted to get some data back from his robots, so an inexpensive off-the-shelf solution wouldn’t be up to the task. Like all good geeks, [Patrick] decided to build what he needed.

For analog control, [Patrick] decided to use a Wiimote nunchuck. This turned out to be a very good choice – the nunchuck has a 2-axis joystick and 3-axis accelerometer in one small, easy to interface package . The wireless radio is taken care of with an XBee module. For the microcontroller, custom “lcd backpack” was created that provides an I2C port for the nunchuck, inputs for the buttons and the single pot, and 2 serial ports for the FTDI and XBee.

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