Given a microcontroller with a digital IO pin and an LED, we know that we can provide a PWM signal to vary the percieved level of light emitted. Thanks to Forrest Mimms, we also know that LEDs can sense light levels. As solid state devices, LEDs can switch state rapidly and other projects have switched between driving the LEDs and reading light levels from them at a pace faster than the human eye can follow.
The light fixture idea is as follows: Some number of LEDs would be connected each to its own IO line on the microcontroller. The controller would perform a sigma delta A2D read on the voltage from the LED to set the light level in that area. It would then output a PWM signal inversly proportional to that reading to the LED for a fraction of a second and then the process would repeat.
Each of the LEDs would be encase in a short opaque tube which would point in a specific direction. This array would be arranged to cover the area to be illuminated.
Since each section of the total area is serviced by its own LED, areas that are darker (farther away, having less light from other sources, etc... ) would recieve more light from the fixture.
At the same time, any changes in the light level reading between the elements could be used to detect motion which would allow the fixture to only come on when needed.
Further, when another fixture is in view of one element, very rapid, full scale changes in light level would be detected and could possibly trigger a mode change from illumination to communication. i.e. the fixtures would see each other, and use thier directional LEDs to communicate data forming an adhoc network.
Information such as light levels (obviously) and motion in different areas, as well as data from added sensors such as temperature, humidity or smoke detectors could be transmitted throughout the house.
|file: /Techref/idea/zlight.htm, 2KB, , updated: 2006/2/15 15:58, local time: 2017/12/16 23:50,
|©2017 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?|
<A HREF="http://www.piclist.com/techref/idea/zlight.htm"> Light fixture with Multi-zone light level detection and compensation</A>
|Did you find what you needed?|
PICList 2017 contributors:
o List host: MIT, Site host massmind.org, Top posters @20171216 RussellMc, Van Horn, David, Sean Breheny, James Cameron, alan.b.pearce, IVP, Neil, Bob Blick, David C Brown, John Gardner,
* Page Editors: James Newton, David Cary, and YOU!
* Roman Black of Black Robotics donates from sales of Linistep stepper controller kits.
* Ashley Roll of Digital Nemesis donates from sales of RCL-1 RS232 to TTL converters.
* Monthly Subscribers: Gregg Rew. on-going support is MOST appreciated!
* Contributors: Richard Seriani, Sr.
Welcome to www.piclist.com!