Are there light switches in your home that aren't as conveniently located as you would like? This laser-based switch decoder and driver allows for flexible control of those lights located in less than ideal places.
I live in an apartment. My kitchen is boring and can be accessed from either end of a central counter. This laser based control, mounts just below the cabinets, scans across the entire sink's counter surface using a single beam of a modified laser pointer. The interrupter beam is detected, processed to provide multiple possible hand based gestures, and the result drives a small relay that enables and disables the light fixture directly over the sink. Sure makes getting a drink of water a bit more interesting.
There are three assemblies in this project. Fashioned out of pill containers and a modified surge protector assembly, they include a wall mounted reflecting mirror, an enclosure with the laser, photo resistor, an indicator LED, an assembly providing AC based power, controller, and relay hardware.
The laser is only modified to minimize its physical length. I used an inexpensive laser pointer and cut the body down past its battery enclosure to just above the pointer switch.
The laser is PWM modulated to reduced the power and also varied depending on whether the laser is detected or not detected. The power to the laser is also a bit reduced because the voltage delivered to the laser module incudes some small losses from controllers driver and in the cabling to the laser/photo detector module. There are also a few other driver features that provide 'debounce' delays between hand swipes so as to distnguiish the hand motions.
I found that for long light path lengths the laser power will likely want to be greater/ brighter because the detected light is more dispersed over the longer path. This can be adjusted at the regulator or by shorting 1 of the the 2 diodes shown in the regulator related schematic.
So I understand the principal operation is a beam interruption with some smarts behind it. Two questions: Why did you choose a visible red laser beam rather than an invisible IR LED? Second, as I understand it, laser pointers are not meant for continuous operation due to internal heating. Did you take any steps to keep the laser cooled to prevent its early demise? Thanks RW
The Attack Dyno brings car enthusiasts an attack timer and dynamometer in a small, portable package with the ability to output vehicle torque, speed, horsepower, 1/4 mile times, 0-60 mph acceleration times, ambient air temperature, and more.
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