DIY Night Vision Monocle

This interesting mashup shows it’s easy to make your own night vision goggles. It makes use of just a few parts; the viewfinder from an old camcorder, a low-light security camera module, and a collection of infrared LEDs.

The low-light camera is capable of detecting infrared light, which is invisible to our eyes. If you shine the right IR LEDs on an object, they will cast enough light for the camera to clearly view the objects around you. The camcorder viewfinder is nothing more than a compact way to display what the camera sees. This would be easy to accomplish with a wearable display. It is also beneficial to have a large IR light source so you may consider modifying that giant LED flashlight you’ve been meaning to build so that it operates in the infrared wavelengths.

This project comes from the same source as the Laser Microphone we looked in on last month. Just like that one, there’s plenty of extra information about this build. There’s suggestions for choosing and focusing a light source. This includes using lasers as the source, and binoculars for long-range viewing.

Laser Mic Makes Eavesdropping Remarkably Simple

Here’s a surprisly simple way to build yourself a laser-based listening device. It consists of two modules, a transmitter and a receiver. The transmitter is a set of lasers, one is visible red for aiming, and the other is infrared for measuring the vibration of a surface. Point the transmitter at the window of the room you want to listen in on and the laser can be reflected back to the receiver. The receiver module has a phototransistor to pick up the infrared laser light, and an LM386 audio amplifier to generate the audio signal sent to a pair of headphone. The need to be well-aligned which is easy enough using a pair of tripods. Check out the demo after the break.

Looking for something to do with the leftover laser diodes from this project? Try making yourself a laser microscope.

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Wii Sensor Bar Projector

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

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

[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

[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

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]