September 19, 2013 /
While 3D tv’s didn’t seem to take off, 3D printing sure has. And once thing leads to another. Now 3D Scanning is getting kind of hot. There’s a project on Kickstarter that is promoting a 3D Scanner for use on mobile devices. It can also do regular USB so it can be used on other devices or home-brew applications as well.
The device seems to be battery-powered, and uses infra-red LEDs and a camera to measure distance and scan. The range is 40 cm to 3.5 meters and promotes an accuracy of 1%. The current things demonstrated are a room scanner app that lets you take dimensions of a room by panning the camera around. An object scanner that can let you make a 3D model (for use in CAD or 3D Printing). And a virtual reality game.
Cool technology, it just means that this type of stuff is getting closer to being a cheap commodity for regular users.
Check out the video after the break.
September 13, 2013 /
Security researcher Silvio put together his process for defeating a cheap infra-red based security system. The security system uses an infra-red remote to arm and disarm the alarm. The alarm is triggered by any motion that happens while it is armed.
In his first attempt he tried to use an off the shelf learning remote to record the signal and play it back. For whatever reason the remote didn’t like the signal and didn’t even try to learn it. So in his second attempt, he whipped out a frequency counter and an oscilloscope and was able to replicate the signal using an Arduino and an infra-red LED. For fun he also made a third attempt using a more hacker friendly open source board called a USB Infrard Toy made by Dangerous Prototypes.
A good read if you want to learn the process of simple reverse engineering. Full article here.
September 5, 2013 /
This build uses good old FSK (frequency shift keyring) technology sending 1′s and 0′s through the air. Although its applied using infra-red, the same concept is used for RF. Also Infra-red is still technically wireless (lol). So on to the build. Just in-case you want to brush up on your FSK I recommend just straight up hitting wikipedia. (If not, here’s the TLDR version; A steady pulse is used to represent a 1, and a variation in the pulse width is used to represent a 0)
On the transmitter side a 555 timer is set up as a Astable Multivibrator, the digital input (fed from say a microcontroller) pulls down the transistor which modifies the frequency of the 555 timer, causing a 0. Leaving the pin high (representing a 1) leaves the 555 timer alone. The data is transmitted via infra-red led.
On the receiver side, a 565 PLL (Phase Lock Loop) IC locks on to the frequency of the 555 timer and outputs a 1 or a 0 when the signal alternates between the 2 frequencies.
This is a great project but mostly as an educational one. Full post up on gadgetronicx.
August 12, 2013 /
On the 20 some-odd remotes I have around the house, I know there are a bunch of buttons on some of them that don’t do anything for my model of whatever it controls. Badr noticed the same thing on his satellite receiver. So he decided to give those extra buttons something to control.
Armed with a little IR transmission know-how, a 16f84a, a transistor array and some relays he added support for controlling his some lights and a fan.
He’s got a schematic and source code up here.