xlisus @ instructables.com writes:
Choose the hue of light that makes you feel more comfortable.
Simple bluetooth remote control from which you can modify lighting from your mobile device or tablet.
– You have two separate RGB channels where you can get different colors per channel.
– Control adjustable intensity.
– Do it yourself .
– Thanks to the arduino platform in minutes you ‘ll Omniblug armed and ready for use.
Discover all the features provided. Is very easy install this small device.
Android Bluetooth Control Led RGB - [Link]
To satisfy electronic DIY hobbyists, ICStation has developed MAX7219 Dot Matrix Module. It uses the Max7219 chip which do a great job on saving of MCU I/O. It can not only control each point individually, but also can be extended without limitation to meet your requirements on LED Sign, Team Logo and so on.
What’s more, it’s controlled by the STM8S003F3 MCU with 1K data storge space which is low cost, low power consumption, very powerful.
DIY LED Sign with MAX7219 Dot Matrix Module - [Link]
This GU10 LED spot light is cheap (£3 including postage) and bright. But it’s also lethal! There’s a 50% chance of putting live mains within a few microns of the metal casing (which is what you’ll be holding when you insert it) and there’s no earth to protect you. It’s like playing Russian Roulette with 240v AC mains. This sort of thing gives new technology a bad name. Avoid it if you want to stay alive.
Dangerous GU10 LED Spot Light is Cheap and Bright but could Kill You – Seriously - [Link]
Julian Ilett writes:
I discovered that due to a lucky co-incidence of voltage and internal resistance, a 100W LED can be connected directly across the terminals of two 18V Nickel Cadmium power tool batteries. And that means you can build a 100 Watt (7,500 Lumens) flashlight for less than $10 (not including batteries).
Monster 7,500 Lumens 100W LED Flashlight for under $10 - [Link]
frankenroc @ instructables.com writes:
You don’t have to be in Times Square to enjoy large bright displays of lights. You can create that in the comfort of your own home with some foam board, LEDs, and our little friend Arduino.
My sister-in-law decided to get married on New Year Eve, and the venue she chose stays open until 1am that night, so I started thinking it would be great to have a nice big countdown clock. I ran the idea past her and her fiance and they both loved it, so I went to work.
When I made it I intended it for just one use, but it’s a very impressive display that can be seen across a huge room. This is pretty simplified and what I’m showing you is on a breadboard. Optimizing and taking it beyond prototyping (e.g. replacing the breadboard with some pcb boards) are outside of the scope for this but shouldn’t be too difficult.
Giant Two-Digit Countdown Clock - [Link]
High color fidelity approaching an ideal is a common feature of „high CRI“ Osram LEDs with CRI up to 96.
When you recall to lessons of physics from your basic- or grammar-school, probably you´ve heard a term „black body radiation”. As we know, each object with a given temperature radiates in a wide range of wave lengths, while a maximum of a radiation depends on its temperature. We mention it because the Sun also operates on this “principle” and its spectrum (light) depends mainly on its surface temperature. Temperature of an object is also the most important factor influencing whether the light will be “warm” or “cold”, that´s why a term color (chromacity) temperature CCT is used.
Even though a portion of radiation (some wave lengths) is absorbed in atmosphere, it can be said that it is very near to a black body spectrum and it´s ideal for us in respect to a pleasant and true color perception.
There are several methods to evaluate color fidelity and one of the most important is so called CRI (color rendition index, maximum = 100). To an ideal light source with CRI =100 is very near a classic incandescent bulb, even though it´s spectrum is shifted towards warmer tones. Unfortunately a light spectrum gained from hot surfzce object also contains a large portion of thermal (infrared) radiation, what causes a low efficiency of incandescent bulbs. However LEDs deploy emission of photons on an other principle (change of electrons energy), so their surface is in fact “cold” in comparison to what temperature a black body radiator should have to gain a similar spectrum.
Modern LEDs have a high CRI, usually over 70. But among LEDs we can find types with even higher CRI (above 80) , as well as “color champions” with even higher CRI. To such champions also belong LEDs from the OSLON Square series, which we introduced to you in our article New LED OSRAM OSLON Square withstands up to 1.5A. Since then company Osram advanced in development and was able to make types with a typical CRI 96 (!), for example LCWCQAR.CC-MPMR-5J7K-1 (4500K).
Light fidelity of this LED is extremely high and such light is very suitable for lighting of areas with high requirements for a light quality, like for example: galleries, museums, shops, photographic ateliers as well as for an everyday work. Despite a high CRI, this particular type also features a considerable efficiency of 180-224 lm/700 mA and a max. current up to 1500 mA.
Among novelties from company Osram can also be found the Oslon Square 2nd generation with even betterthermal features increasing lifetime and efficiency at high temperatures. Moreover this new 2-nd version is sorted (binning) at 85°C, what ensures minimum color in a real operation.
Almost perfect light from the Oslon Square LED - [Link]
Lee Zhi Xian writes:
I was always fascinated with LED Matrix Display because it makes a good and clear display. I always saw LED display used as advertisement signboard. It can be programmed with variety of animations. So I decided to make myself a 48×8 LED Matrix Display. Of course, I start off with a smaller one by soldering LEDs on stripboard, making a 8×8 LED Matrix. I tried to understand how the LED Matrix works and how to deal with the programming part.
Development of 48×8 Led Matrix Display - [Link]
ZXLee built a simple sensor for Arduino which allows him to detect colors. The idea lies behind using red, green, blue LEDs and Light Dependent Resistor (LDR). Lee Zhi Xian writes:
Previously I have made a colour sensor using Arduino but don’t have the time to update it on my blog. Today I am going to share the details of this mini project. Basically, the sensor consists of three LEDs and Light Dependent Resistor (LDR). The LDR will detect the colour and display it to another RGB LED. Besides display it on the RGB LED, the colour will also display on PC. RGB LED is commonly used in display colours on LCD or OLED such as the monitor and television.
Simple technique of sensing colors using Arduino - [Link]
This relatively simple circuit uses a 6-V DC supply with a PWM current-source configuration to provide efficient, adjustable dimming of a white LED over a wide range, needed to accommodate the unique lighting needs of an optical microscope over its magnification range from 40× to 1000×. by James Campbell
When the built-in incandescent light source of my venerable Olympus microscope failed after many years of use, I decided to design a reliable modern replacement. A 1-W white LED (SEOUL X42182, 350 mA max, Vf = 3.25 V) was the obvious choice to provide high brightness and full-spectrum light without the heat of incandescent or xenon arc lamps. The microscope lamp brightness needs to be adjustable, however, to accommodate the different objective lenses, which offer magnifications from 40× to 1000×.
Current Source For LED Microscope Illuminator Provides Full-Spectrum Light - [Link]
LANp combines an LED RGB Bar from an old scanner, an Arduino and Ethernet/SD Shield to make a full RGB Lamp.
It has a built-in webserver that has an RGB colour picker, which changes the LED bar in real-time.
There is some photos and a YouTube video to show it all working.
LANp – A DIY Arduino network controllable RGB lamp made from scanner parts! - [Link]