Bicycle Heads Down Display Shows You The Way

October 28, 2015 by James Hobson 10 Comments

On a bicycle you’re typically looking ahead and slightly down to make sure you don’t ride over any potholes. While a speedometer is great on the handlebars, what if you could project your speed and other information onto the road ahead? Well, it turns out if you have a smartphone and a bit of ingenuity, you can do just that!

We’ve seen this hack done before with a pico projector, but that’s a pretty big investment for your bicycle. So [Peter] had another idea. What if you could just use your cellphone as is and a bit of optics? It turns out you can buy some pretty cheap “cell phone projectors” from China or Amazon — it’s basically a little cardboard box that your phone fits into, with a cheap plastic lens to project your image. Lumen output is pretty miserable, but if you’re riding at night, it is enough to see by!

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Toy Television’s Dreams Come True

October 21, 2015 by Kristina Panos 12 Comments

A couple of years ago, [Alec]’s boss brought him a souvenir from Mexico City—a small mid-century console television made of scrap wood and cardboard. It’s probably meant to be a picture frame, but [Alec] was determined to give it a better life.

As it turns out, the screen of [Alec]’s old Samsung I9000 was a perfect fit for the cabinet with room to spare. It was on its way to becoming a real (YouTube) TV once [Alec] could find a way to control it remotely. A giant new-old stock remote that’s almost bigger than the TV was just the thing. There’s enough room inside the remote for a non-LE Bluefruit module, which is what the I9000 will accept as input without complaint.

Trouble is, Bluefruit doesn’t support matrix keypads, so [Alec] used a bare ATMega328 running on the internal clock. Since the Bluefruit board provides voltage regulation, the remote was able to keep its native 9V power. [Alec] is happy with the results, though he plans to refine his button choices and maybe make a new overlay for the remote. Stay tuned for a tiny TV tour.

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Etch-A-SDR

October 4, 2015 by Al Williams 3 Comments

What do you get if you cross a software defined radio (SDR) and an iconic children’s drawing toy that we are sure is a trademarked name? If you are [devnulling], you wind up with the Etch-A-SDR. The box uses an Odroid C1, a Teensy, and the ubiquitous RTL-SDR.

The knobs work well as control knobs (as you can see in the video below). When you are bored listening to the radio, you can reset the box and go into Etch-a… um, drawing mode. The knobs work like you’d expect and you can even erase the screen with a vigorous shake.

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Resistance Is… There’s An Augmented Reality App For That!

September 12, 2015 by Al Williams 68 Comments

Like many engineers of a certain age I learned the resistor color code using a mnemonic device that is so politically incorrect, only Tosh might venture to utter it in public today. When teaching kids, I have to resort to the old Radio Shack standby: Big Boys Race Our Young Girls But Violet Generally Wins. Doesn’t really roll off the tongue or beg to be remembered. Maybe: Bad Beer Rots Our Young Guts But Vodka Goes Well. But again, when teaching kids that’s probably not ideal either.

Maybe you can forget all those old memory crutches. For one thing, the world’s going surface mount and color coded resistors are becoming a thing of the past. However, if you really need to read the color code, there’s at least three apps on the Google Play Store that try to do the job. The latest one is ScanR, although there is also Resistor Scanner and Resistor Scan. If you use an iPhone, you might try this app, although not being an Apple guy, I can’t give you my feedback on that one.

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Want A Low-cost ARM Platform? Grab A Prepaid Android Phone!

September 10, 2015 by Adam Fabio 113 Comments

What would you pay for a 1.2Ghz dual-core ARM computer with 1GB RAM, 4GB onboard flash, 800×600 display, and 5 megapixel camera? Did we mention it also has WiFi, Bluetooth, and is a low power design, including a lithium battery which will run it for hours? Does $15 sound low enough? That’s what you can pay these days for an Android cell phone. The relentless march of economies of scale has finally given us cheap phones with great specs. These are prepaid “burner” phones, sold by carriers as a loss leader. Costs are recouped in the cellular plan, but that only happens if the buyer activates said plan. Unlike regular cell phones, you aren’t bound by a contract to activate the phone. That means you get all those features for $15-$20, depending on where you buy it.

The specs I’m quoting come from the LG Optimus Exceed 2, which is currently available from Amazon in the USA for $20. The same package has been available for as little as $10 from retail stores in recent weeks. The Exceed 2 is just one of several low-cost Android prepaid phones on the market now, and undoubtedly the list will change. How to keep up with the current deals? We found an unlikely place. Perk farmers. Perk is one of those “We pay you to watch advertisements” companies. We’re sure some people actually watch the ads, but most set up “farms” of drone phones which churn through the videos. The drones earn the farmer points which can be converted to cash. How does this all help us? In order to handle streaming video, Perk farmers want the most powerful phones they can get for the lowest investment. Subreddits like /r/perktv have weekly “best deals” posts covering prepaid phones. There are also tutorials on rooting and debloating current popular phones like the Whirl 2 and the Exceed 2.

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Hack Puts Aging Sprinkler System Online

September 9, 2015 by Kevin Dady 17 Comments

Water conservation is on a lot of people’s mind, and with an older sprinkler system one may not have the finest control of when and where the lawn is getting its water. Faced with such a system [Felix] decided to hack into his, adding better computerized scheduling, and internet remote control.

The brains of the operation is handled by a Moteino, which is a Arduino compatible micro controller board with WiFi on board. In order to interface with the sprinkler system, an interface PCB is made. The interface has an on board buck power supply to regulate the 24 volt AC power of the sprinkler down to 5 volt DC for the micro and the 74HC595 shift registers.

The output from the shift registers connects to a pin header where the stock computer normally would have plugged in. With a little software and a phone app, the new micro-controller takes over the sprinkler’s TRIAC’s turning on and off zones with a push of the thumb.

Join us after the break for a quick demonstration video.

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Hand Controlled Robot Uses Accelerometer

August 16, 2015 by Al Williams 3 Comments

What do orchestra conductors, wizards, and Leap controller users have in common? They all control things by just waving their hands. [Saddam] must have wanted the same effect, so he created a robot that he controls over wireless using hand gestures.

An accelerometer reads hand motions and sends them via an RF module to an Arduino. This is a bit of a trick, because the device produces an analog value and [Saddam] uses some comparators to digitize the signal for the RF transmitter. There is no Arduino or other CPU on the transmit side (other than whatever is in the RF module).

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