By Katherine Derbyshire:
Light destroys art. Some wavelengths are more damaging, some media are more vulnerable to damage, but all curators and conservators face a fundamental conflict between the demands of preservation and the desire to display the objects in their care. These conflicts come to the forefront whenever a museum must decide which objects to display, for how long, and with what illumination. The recent emergence of museum-quality LED lighting is challenging existing assumptions about the “best” lighting for art objects.
LEDs Offer Efficient, Color-Accurate Museum Gallery Lighting - [Link]
BH1750FVI Is a Digital Light sensor , which is an digital Ambient Light Sensor IC for I2C bus interface. This IC is the most suitable to obtain the ambient light data for adjusting LCD and Keypad backlight power of Mobile phone. It is possible to detect wide range at High resolution.( 1 – 65535 lx ).
BH1750 Digital Light Sensor - [Link]
A light meter is a device that measures the intensity of light. It finds applications in schools, hospitals, production areas, passageways and more to measure and maintain proper lighting levels. It is often used by photographers to determine the proper exposure for a photograph. Today we are going to build a simple light meter using an Arduino board and a BH1750 digital light sensor. The measured lighting level or intensity is displayed on eight seven segment LED displays, in both Lux and Foot-candle units.
Building a simple digital light meter using Arduino and BH1750FVI sensor - [Link]
Here’s an interesting project by Steve of Tangent Audio the AZIZ project, a microcontroller-based LED microscope illuminator:
AZIZ is an LED microscope illuminator that I designed and built from scratch. It is designed around a Texas Instruments TLC59116 constant-current PWM LED driver chip, and an Atmel ATTiny1634 8-bit microcontroller.
AZIZ: DIY LED microscope illuminator - [Link]
I really liked the idea of controlling my “Home Theatre” lights with a remote (TV or other), this would save me the exhausting task of heaving myself off the couch to turn the lights on or off.
I found one of my remotes has a spare power button, its one of those stupid “universal” remotes that comes with DVD players or TVs but only work if you have all the same brand equipment, I don’t so this made a good option for a light switch.
Remote Controlled Home Theatre Lights - [Link]
The MAX44004 is a wide dynamic range, low-power ambient light sensor (ALS) ideal for many light sensing applications: tablets, displays, accessories, medical devices, and light management systems.
The on-chip ambient sensor has the power to measure the exact visible light from 0.03 lux to 65,000 lux and communicate through an I²C digital communication bus. The IC has patented sensors, filters, and circuitry to mimic the human eye response. With on-chip calibration registers, it performs the same in different light conditions (i.e., fluorescent, incandescent). The interrupt pin minimizes the need of constant polling of the device, freeing up microcontroller resources for efficient communication and thus reducing overall power consumption. The part-to-part matching is optimized by proprietary Maxim process to speed up end-product development time.
MAX44004 – Digital Ambient Light Sensor - [Link]
Tenty LED Brake Lights. Pete writes – [via]
I Purchased a motorcycle about two weeks ago. Interestingly, whenever I tell someone this news, they immediately proceed to tell me the most gruesome injuries and stomach turning plights that they or someone they know, has fallen victim to while motorcycling. In some cases, these raconteur’s briefly pause to look over their shoulder, presumably scanning for small children or otherwise offendable ears, before delivering the goriest details.
One commonality in these stories, aside from the macabre and arguably poor timing involved in telling them to me is that many accidents come down to a lack of visibility of motorcycles and their riders. Less than Argus-eyed motorists often pull out into the path of a motorcycle and with insufficient time for evasive action, that quickly an accident has occurred. Other times, drivers may focus on the car ahead of the motorcycle and in the event of stopping at a red light or similar, fail to leave enough room.
Tenty LED Brake Lights - [Link]
Replacing electricity with light: First physical ‘metatronic’ circuit created – [via]
The technological world of the 21st century owes a tremendous amount to advances in electrical engineering, specifically, the ability to finely control the flow of electrical charges using increasingly small and complicated circuits. And while those electrical advances continue to race ahead, researchers at the University of Pennsylvania are pushing circuitry forward in a different way, by replacing electricity with light.
Replacing electricity with light: First physical ‘metatronic’ circuit created - [Link]
Giorgos Lazaridis writes:
I got myself some UV-curable solder mask for my PCB workshop, and as soon as i got it, i discovered that my UV artwork transfer box is totally incapable to activate the UV paint and cure it. I began searching the net for powerful UV lamps, and then it hit me: Some months ago i uploaded a theory regarding the Cold and Hot cathode discharge lamps. During my research for these lamps i found out that they can provide directly visible light (lamps without internal coating), or they produce UV radiation. The lamps that produce UV radiation have an extra coating on their internal surface which glows when excited by the UV rays, thus producing light!
Hack a Hg Lamp to a Powerful UV Light Source - [Link]
Measurement of light intensity is a prime necessity in several occasions. The diversity of such needs make their way to various branches of physics and engineering as well as in media. For instance, in engineering, such kinds of measurements are needed to design optimum lighting conditions of a room. In photography, light intensity measurements ensure good quality pictures by determining the right exposure. Wiring a phototransistor or a light-dependent-resistor (LDR) with an analogue LED voltmeter chip like the LM3914 or even to a microcontroller and displaying the ADC values is a pretty simple technique of measuring light intensity. The bad part of this technique is that these simple and amateur-level devices can only measure relative intensity of light and are unable to provide measurements on an absolute scale. However, with a precise knowledge of the transfer characteristic (resistance vs light intensity) of the LDR it is possible to relate the LDR output to the intensity of light in standard unit. In case the LDR characteristic is unknown or unreliable, you can still calibrate the sensor output by using a variable light source and an external reference photometer. This project is about a microcontroller based light intensity meter where an LDR light sensor is calibrated against an external photometer to obtain the intensity of incoming light in the unit of lux. The lux is the SI unitm of illuminance and luminous emittance, and measures lumens per square meter (lm/m2). The microcontroller used in this project is ATMega8L and its firmware is written using mikroElektronika’s MikroC Pro for AVR compiler.
Building a digital light meter with a calibrated LDR - [Link]