Build Your Own Gear VR

With Samsung’s new Gear VR announced, developers and VR enthusiasts are awaiting the release of the smartphone connected VR headset. A few people couldn’t wait to get their hands on the platform, so they created, OpenGear, a Gear VR compatible headset.

The OpenGear starts off with a Samsung Galaxy Note 4, which is the target platform for the Gear VR headset. A cardboard enclosure, similar to the Google Cardboard headset, holds the lenses and straps the phone to your face.

The only missing part is the motion tracking electronics. Fortunately, ST’s STM32F3 Discovery development board has everything needed: a microcontroller with USB device support, a L3GD20 3 axis gyro, and a LSM303DLHC accelerometer/magnetometer. These components together provide a USB inertial measurement unit for tracking your head.

With the Discovery board strapped to the cardboard headset, an open-source firmware is flashed. This emulates the messages sent by a legitimate Oculus Rift motion tracker. The Galaxy Note 4 sees the device as a VR headset, and lets you run VR apps.

If you’re interested, the OpenGear team is offering a development kit. This is a great way for developers to get a head start on their apps before the Gear VR is actually released. The main downside is how you’ll look with this thing affixed to your face. There’s a head-to-head against the real Gear VR after the break.

[via Road To VR]

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DIY Phone Charger Born From Cyclone Disaster

As convenient as cell phones are, sometimes these power-hungry devices let us down right at the worst time. We’re talking about battery life and how short it is in modern cell phones. Sure that’s totally inconvenient sometimes but it could be way worse. For example: during a natural disaster. A cyclone hit [Ganesh’s] home city and the entire area had lost power for 10 days. He couldn’t plug in his phone to charge it even if he wanted to. After realizing how dependent we are on the electrical grid, he did something about and built a phone charger out of parts he had kicking around.

The charger is quite simple. The user cranks on a DC motor and the output power goes into a LM2596-based step-down voltage regulator. The output of the regulator is then connected to a female USB connector so that any USB cord can be plugged in. As long as the motor is cranked fast enough to put out at least 8vdc, a steady stream of 5v will be available at the USB connector. Max current output of the system has been measured at 550mA.

[Ganesh] admits this isn’t a practical every-day charger but in a pinch it will certainly do the trick. It is even possible to build a makeshift charger out of a cordless drill.

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Reverse Engineering the Kayak Mobile API

The travel meta-search website Kayak apparently used to have a public API which is no longer available. We can’t say we mourn the loss of the interface we’d never known about. If you are someone who was automating their searches for that perfect vacation getaway deal, there’s still hope. But either way you’ll like this one. [Shubhro Saha] figured out how to access the API used by the Kayak mobile app. We like that he details how to sniff the traffic between an app and the internet and make sense of what is found.

His tool of choice is the Python package Mitmproxy. We haven’t heard of it but we have heard of Wireshark and [Shabhro] makes the case that Mitmproxy is superior for this application. As the name suggests, you set it up on your computer and use that box’s IP as the proxy connection for your phone. After using the app for a bit, there is enough data to start deconstructing what’s going on between the app and remote server which which it communicates. We could have a lot of fun with this, like seeing what info those free apps are sending home, or looking for security flaws in your own creations.

[Thanks Juan via Twitter]

Controlling Nokia Phones with Arduino

While [Ilias Giechaskiel] was waiting for his SIM900 shield to arrive, he decided to see what he could do with an old Nokia 6310i and an Arduino. He was researching how to send automated SMS text messages for a home security project, and found it was possible to send AT commands via the headphone jack of Motorola phones. But unfortunately Nokia did not support this, as they use a protocol known as FBus. With little information to go on, [Ilias] was able to break down the complicated protocol and take control with his Arduino.

With the connections in place, [Ilias] was able to communicate with the Nokia phone using a program called Gnokii — a utility written specifically for controlling the phone with a computer. Using the Arduino as an intermediary, he was eventually able tap into the FBus and send SMS messages.

Be sure to check out his blog as [Ilias] goes into great detail on how Nokia’s FBus protocol works, and provides all source code needed to replicate his hack. There is also a video demonstration at the end showing the hack in action.

Reverse-Engineering a Superior Chinese Product

It makes an Arduino look like a 555.  A 364 Mhz, 32 bit processor. 8 MB RAM. GSM. Bluetooth. LCD controller. PWM. USB and dozens more. Smaller than a Zippo and thinner than corrugated cardboard. And here is the kicker: $3. So why isn’t everyone using it? They can’t.

Adoption would mandate tier after tier of hacks just to figure out what exact hardware is there. Try to buy one and find that suppliers close their doors to foreigners. Try to use one, and only hints of incomplete documentation will be found. Is the problem patents? No, not really.

[Bunnie] has dubbed the phenomenon “Gongkai”, a type of institutionalized, collaborative, infringementesque knowledge-exchange that occupies an IP equivalent of bartering. Not quite open source, not quite proprietary. Legally, this sharing is only grey-market on paper, but widespread and quasi-accepted in practice – even among the rights holders. [Bunnie] figures it is just the way business is done in the East and it is a way that is encouraging innovation by knocking down barriers to entry. Chinese startups can churn out gimmicky trash almost on whim, using hardware most of us could only dream about for a serious project.

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Selfie-Bots Will Take Your Best Shots For You

Professor [Bruce Land] teaches a microcontroller class at Cornell University, and it seems like this year’s theme was selfie-taking-robots.

First up is a clever mix of technology by [Han, Bihan and Chuan]. What happens when you take an iPhone, three microphones and a microcontroller? The ultimate device in selfie-taking-technology, that’s what — Clap-on! The iPhone is mounted on a few servo motors which allows the bot to direct the camera towards, you guessed it, a clapping noise. On the second clap, the phone takes your picture. Cute.

Next up is a bit more sophisticated — a facial recognition selfie-bot. This little robot can be programmed to track faces and take pictures of you and your friends when your arm is just not long enough. Not only that, you can set all kinds of parameters so you get the perfect picture. It uses OpenCV to crunch the raw data and outputs commands to an ATmega1284 which controls the servo motors that direct the camera. This project was by [Michael and Jennifer] — two fourth year students at Cornell.

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PeriUSBoost: A DIY USB Battery Pack

If you travel often, use your mobile devices a lot, or run questionable ROMs on your phone, you likely have an external USB battery pack. These handy devices let you give a phone, tablet, or USB powered air humidifier (yes, those exist) some extra juice.

[Pedro]’s PeriUSBoost is a DIY phone charging solution. It’s a switching regulator that can boost battery voltages up to the 5 volt USB standard. This is accomplished using the LTC3426, a DC/DC converter with a built in switching element. The IC is a tiny SOT-23 package, and requires a few external passives work.

One interesting detail of USB charging is the resistor configuration on the USB data lines. These tell the device how much current can be drawn from the charger. For this device, the resistors are chosen to set the charge current to 0.5 A.

While a 0.5 A charge current isn’t exactly fast, it does allow for charging off AA batteries. [Pedro]’s testing resulted in a fully charged phone off of two AA batteries, but they did get a bit toasty while powering the device. It might not be the best device to stick in your pocket, but it gets the job done.