by By Ben Coxworth @ gizmag.com:
It’s the big paradox of emergency-use flashlights … by the time you eventually need to use them, their batteries have died. Eton’s new Blackout Buddy H2O, however, will reportedly still work after sitting for up to 10 years. And to turn it on, you just add water.
This latest member of the Blackout Buddy line has a magnesium-oxide battery, which starts delivering power to the light’s three LEDs when exposed to H2O. To initially fire it up, you dip it into a small cup of water, or pour water into its battery compartment. After that, it will keep going continuously for up to 72 hours – if it starts to dim within that time, you simply add more water.
Blackout Buddy H2O runs on water to provide emergency lighting - [Link]
Davide Gironi writes:
A Spark.io library for the BH1750FVI IC.
The BH1750 IC is a light intensity sensor module with built-in a 16 bit AD converter generating digital signal. With the BH1750 Light Sensor intensity can be directly measured by the luxmeter, without needing to make calculations. This library provides function to measure lux through I2C on a Spark Core.
Measure brightness in Lux using BH1750 sensor on Spark core - [Link]
by Vadim Panov:
Back when I was only starting to dabble in electronics, I needed a project that would meet the following requirements:
simple to make;
original (i.e. done entirely by myself from scratch);
containing a microcontroller;
and maybe the most important of all, useful. I’ve had enough devices I assembled just to dismantle the whole thing a month later.
The thing I came up with at the time was a light swich for my room controlled over an IR remote from TV. Remote that I had used RC-5 protocol, hence the firmware is suited for any RC-5 compatible remote.
Everyone is familiar to the everliving problem with switching the lights off in your room before going to bed and stumbling back across the room. The IR switch I describe here solves that problem, and I can definitely tell that this project was a success – I am still using it with no regret.
Infrared remote controlled light switch with ATTiny2313 - [Link]
Just wanting to share one of my latest projects, made possible by DirtyPCBs. I got a lot of good boards (actually 2 designs) and saved 25$ using this service. Very nice.
It’s a simple thing, just a micro (ATmega168) + a bunch of WS2812B LEDs. Main purpose: more colours
It’s meant to fit nicely into IKEA Samtid lamps, runs with 5V DC and takes up to 2.75A. The control module is removable, so one doesn’t have to rip the lamp apart every time you change code. I used microMaTch connectors, as they’re somewhat low profile, at least compared to standard headers, and provide quite good mechanical support.
IKEA Samtid mood-light upgrade - [Link]
Pulse-controlled dimmers of lighting – Finder series 15 offer an elegant solution of lighting dimming controlled by a single switch.
Possibility to control level of lighting is beneficial at least from two reasons – saving of energy and naturally – we don´t need always a full intensity of lighting. At watching of media-projector presentation, TV, illumination of corridors, … it´s often desirable only to reach only a minimum level of illumination (but not a total darkness). Light dimmers are for a long period used for these purposes, usually based on a phase regulation.
Solution from company Finder is exceptional in a fact, that it´s usable with almost every light source – for example incandescent bulbs, 230V halogen bulbs powered by a toroidal or EI transformer, dimmable CFL lamps, as well as LED bulbs. The essence of Finder 15 series dimmers versatility is in the possibility to choose a method of a phase regulation – on the beginning of the sinusoid, or on its end (leading/ trailing edge – the difference is illustrated on the attached picture). The first method is generally suitable for electronic transformers for halogen bulbs and LEDs, the second method is better for classic transformers for low voltage bulbs, for 230V CFL and for 230V LED lamps.
As it uses to be, control of such dimmers is maximally simple – by a short push of a control button (switch) the relay (output) will switch on or switch-off. By a longer holding the button presses, we can change the light intensity from minimum to maximum and vice versa. Finder 15 series dimmers also enable to work in a mode with a switched on memory (after a repeated switch on, the last used level of intensity will be set) or without a memory (after switching on, the maximum intensity will be set). An above standard benefit is a possibility to adjust a minimum light intensity by a potentiometer, what´s important mainly at electronic transformers to avoid a possible blinking at very low intensities and it´s also at classic incandescent bulbs, as their efficiency drops down rapidly at very low intensities (duty cycles).
All 3 produced types are available directly from our stock:
18.104.22.168.0404 – assembly to installation boxes, linear dimming (also available types with dimming in 10 incremental steps)
22.214.171.124.0500 – assembly to boxes or on a panel, linear dimming
126.96.36.199.0000 – DIN rail assembly, linear dimming
Available are various versions, detailed information and a comprehensive table about possibilities of usage of particular types will give you the Finder 15 datasheet.
One impulse is able to set intensity of luminance - [Link]
by Deddieslab :
I have a couple of front door LED lights which I would like to switch on automatically during the evening/night. The two conventional methods that are commonly available had their disadvantages:
A timer switch is the easiest and cheapest solution, but doesn’t take into account day light savings. Besides that, in Einhoven, the Netherlands where I live in december the sun sets around 16:30 while in June it doesn’t get dark before 22:00. A simple timer doesn’t take that into account either.
Since you only want the lights on when it gets dark, instead of time you can also use a light sensor to distinguish day and night. You have these front door lights that have this built in. The problem that I had with these devices is that they start bouncing (‘flickering’) around sunset/sunrise. They constantly turn on/off which causes damage to the LED lights I was using. This cost me already several expensive led lights.
Frontdoor light switch based on local sunset/sunrise - [Link]
by dreded @ dredx.com:
In my home I have a fairly long hallway that has light switches at either end but 99% of the time we enter the hallway from the middle where there is no switch. So I decided I needed to do something about this as walking down a dark hallway all the time was annoying.
I have seen a fair number of people use an arduino or even a standalone ATTiny85 with a El cheapo HC-SR501 which can be found on ebay for about $1.25 each and I find these things work fantastic, they have an excellent range and detection spread.
Motion activated lighting without a Micro-Controller - [Link]
Another Instructables by Jan Henrik, a police light with a Attiny25/45/85. He writes:
Hello, in this project I want to show you how to build a multi functional Police Light with a Attiny25/45/85 .
It will have several animations , which can be changed with a button on the circuit board, it has 2 channels, which can be controlled with PWM. That allows us to add serval animations or police light flashing sequences. The maximum rated current per channel is 500mA, that allows us to control high power LED´s, LED stripes or old Light Bulbs!
Attiny25/45/85 police light with Arduino - [Link]
Jaanus Kalde made this 32 channel light dimmer project, that is available at Github:
I needed a computer controllable 32 channel light dimmer for an art installation. After looking around a bit I found out that there isn’t even a Arduino shield for the work. So I made a quick 4 channel stackable board to control lights. The board uses SHARP thyristor based solid state relays to switch mains voltage. As normal with thyristors – all the outputs can be used as dimmers through zero-crossing detection. All outputs are able to handle 0.9 A / 200 W. We connected 40 W incandescent light bulbs to it but you can control whatever with it – lights, electronics, computers, motors etc.
32 channel mains lamp controller - [Link]
Raj @ embedded-lab.com writes:
A light meter is used to measure the intensity of illumination in a given area. It is widely used in schools, warehouses, factories, hospitals, office buildings, museums, art-galleries, parking garages, stadiums, and many more, to measure and maintain proper lighting levels. The intensity of illumination is usually expressed in Lux or foot-candles. As the 4th project in our chipKIT tutorial series, today we are going to build a digital light meter using the chipKIT Uno32 board and the BH1750 digital light sensor. This project uses Digilent’s chipKIT Basic I/O shield for displaying the measured light intensity in Lux, foot-candles, and Watts/m^2 units.
chipKIT Project 4: Digital light meter - [Link]