Wii Sensor Bar Projector

September 16, 2010 by Mike Szczys 19 Comments

Having experienced quite a bit of trouble getting the Nintendo Wii remotes to work reliably with his home theater projector, [Sprite_TM] designed his own sensor bar replacement. If you’re not familiar, the Wii remotes have an infrared camera in the tip that sense two IR LEDs in the sensor bar that resides above or below your television. The problem is that if you’re too far away, the points of light are not where the remote expects them to be and the cursor will not perform as expected. Since this is a huge projected display it’s no surprise that the player is further away from the screen than the system was designed for.

[Sprite_TM’s] solution was to build a projection system for the two IR points. The unit in the picture above is a driver circuit with two IR emitters mounted on a heat sink, each with its own reflector. The reflected beams are shined through a Fresnel lens and projected on the same wall as the TV image. The viewer will not be able to see this light as it’s in a longer wavelength than the visible spectrum. But the Wii remote performs beautifully now and the replacement sensor bar is happily mounted out of sight above the projector.

Build Your Own Magnetic Levitator

August 31, 2010 by Mike Szczys 34 Comments

Here’s a great magnetic levitator build. [Scott Harden] dug up the link after seeing that awesome rotating globe this morning. This version hangs objects below an electromagnet but it has a sensor system to provide a constant distance between magnet and object even if the payloads are a different weight. This is done with a couple of infrared sensors. One acts as a reference detector, always viewing an IR LED in order to get a baseline measurement. That measurement is compared to a second detector mounted slightly lower. The circuit adjusts the electromagnetic field, making sure the object is always breaking the lower beam but never interrupting the reference beam. No microcontroller needed, this is handled with a couple of OpAmps. See it in action after the break.

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Manual Transmission Gear sensor

May 9, 2010 by Mike Szczys 57 Comments

[Ben] bought a remote starter for his car but needed a way to make sure the manual transmission was in neutral when starting. He built this infrared sensor frame to detect the position of the stick. It uses four beam paths which will tell him the exact gear or neutral position of the shifter. For this project he just needs to detect neutral but exact gearing is apparently necessary information for his next hacking project. We initially were worried about sunlight interfering with the sensor readings but he’s building this to go under the collar that is used to cover up the mechanical joint at the base of the stick.

Update: IR Controlled Lighting

April 26, 2010 by Mike Szczys 11 Comments

[Muris] is back with another infrared controlled lighting hack. When we checked in with him last year he was showing off an IR controlled dimmer module. Now he’s back with this device that is CFL friendly. Because standard CFL bulbs are not dimmer compatible he’s adapted the project away from dimming and toward switching. The new design still uses an infrared remote but now it can turn two devices on and off again or toggle between them. Our favorite part of the build is that the PIC based device can learn the codes of whichever remote you choose, rather than having to rely on one specific type of remote.

Infrared Transmission Decoding

April 21, 2010 by Mike Szczys 12 Comments

Alright class, quiet down and open your books to the chapter on Manchester Encoding. [Brian J Hoskins] did just that when building this RC5 decoder. This protocol is commonly used in television remote controls. You use them on a daily basis, don’t you think it’s time you understood what’s going on? Check out his writeup and learn the dark art of invisible light communication. Or just skip the learning and follow our how-to.

[Thanks Tim]

Location Tracking Using IR Throwies

December 30, 2009 by Mike Szczys 14 Comments

[Joe] and his team hacked together some location tracking using IR throwies for their final project. The challenge they undertook was to find a way to track the orientation of a sculpture in the form of a rotating metal cube. The end result dips its toe into the augmented reality pool but the methods are what interest us.

They wanted this to work day or night so contrast would be a major issue if working completely with image manipulation. Having a simple way to pick out the corners of the monotone block would make this process a breeze. They ended up using magnetic throwies that have an infrared LED which can easily be picked up by a webcam no matter what the ambient light issues happen to be.

After the break you can see these guys out in the wild testing the system. We’d like to note the diffusers used in the project. We’re used to seeing ping-pong balls as diffusers but this is the first time we’ve noticed Styrofoam balls being used.

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Mac Mini – Getting A Little More Useful

November 4, 2009 by Jakob Griffith 25 Comments

We’re pretty sure Apple decided to implement an IR sensor in their Mac Mini line simply to mock the user. For those who are unaware, the built in sensor only works with the standard Apple Remote; unless you happen to have a programmable PDA or similar you’re SOL. An alternative solution would be to install a USB IR receiver. But then your beautiful Mac Mini is forced to sit alongside an ugly black box. Why not have the best of both worlds? [SqueeZe] wrote an (almost) entirely non invasive tutorial for placing a USB IR receiver inside his Mac Mini. Reminds us of a certain hack a while back, but the objective was to get the IR receiver outside of the unit rather than inside. Different people, different worlds.

[Thanks Kiran]