Vlorbschnat @ instructables.com writes:
What follows are instructions for constructing a battery powered portable VU meter, as well as detailed instructions for the construction of the PCB needed to complete this project. It was designed to illuminate from 0-10 LEDs depending on ambient sound levels. I designed it to be attached to a wristband, clothing, or a necklace if the design is scaled down somewhat. Its purpose is to be worn in a nightclub or similar locale where music is playing, as an animated alternative to a glow stick. It can be used, however, for a variety of alternative purposes.
Battery Powered Portable VU Meter - [Link]
Dave proves he has no fear by opening this can of electronic worms by posing the question – “Does Current Flow Through A Capacitor?” The answer may surprise you, or drive you into a physics induced rage…
Does Current Flow Through A Capacitor - [Link]
ledartist @ instructables.com
My obsession of this year is full-color LED. I have made Aurora 9×18 as a result. As much as I love the scale of Aurora 9×18, I also wanted to have something smaller, perhaps something that can go on a costume.
Here’s Aurora mini 18. It has 18 full-color/RGB LEDs on a smallest possible circle. With a single PIC microcontroller, changing 18 RGB LEDs smoothly is reaching the technical limit. With the new PIC with wider supply voltage, the circuit is simplified compared to Aurora 9 bar, and use of two AA or AAA batteries (3V operation) or one Lithium battery is now possible.
Aurora mini 18 - [Link]
Gina Roos writes:
One of the biggest challenges faced by solid-state lighting designers is reliability. Electrical and thermal conditions are two major factors affecting device life and lighting output and, while long life is a key benefit of LEDs compared to incandescent and fluorescent light sources, all bets are off if the LEDs exceed their temperature ratings.
Thermal management continues to vex LED lighting designers, particularly for high brightness LEDs that continue to escalate in forward current while decreasing in package size. Couple this with potentially high-temperature applications such as streetlights and high-bay lighting in warehouses, and it becomes apparent that there is a major hurdle to overcome.
With an estimated 20 percent of global energy used for lighting, LED driver suppliers are more than aware of these challenges and are starting to integrate thermal foldback control into some of their designs to protect LEDs from failure and reduced lifetime due to high-temperature environments. Thermal foldback limits the LED temperature to protect against failure by reducing the LED current as the ambient temperature increases; this arrangement continues to decrease the current until the LED junction temperature returns to a safe operating temperature. The result is higher reliability, longer operating life, and, in some cases, increased safety.
How Thermal Foldback Improves the Reliability of LED Lighting Fixtures - [Link]
What is the JTAG interface and Boundary Scanning, how does it work, and what is it useful for?
What is JTAG and Boundary Scan? - [Link]
by Publitek European Editors:
This article describes the development of touch sensing and switching techniques capacitive sensing technology. Products cited include both stand-alone capacitive sensing controller ICs and microcontrollers (MCUs) that include touch sensing as a peripheral function. Capacitive touch sensing has experienced explosive growth to become the default human interface for several classes of consumer product. Users of tablets, smartphones, portable media players, and GPS systems now expect a sophisticated and responsive touch interface as a matter of course. This, in turn, has modified the expectations that the user base has of the smart device and domestic appliance markets; consumers now come, in effect, pre-programmed with the language of tap, drag, swipe, and pinch. High-end products that do not offer that mode of user interaction risk being “uncool”.
Capacitive Touch Sensing Moves from Exotic to Everyday - [Link]
This project is named “Engadino” after Engadin – ski resort in Switzerland. The reason for this is that I live in Switzerland, I like skiing and the name is easy to remember and pronounce. By itself the project is a clone of “Pinguino”.
Engadino - [Link]
Milen @ instructables.com writes:
The purpose of the project was to create an external USB audio card, which could be able to:
1) serve as usual external USB audio card with headphone/line output and audio line input
2) can transmit the digital audio data at relatively long distance (20m -100m)
3) can receive and process the digital audio data send by the similar card and either transfer it through the USB to the PC, or convert it to analog audio signal
As long distance transfer media was chosen the POF.
A short explanation of the POF technology will be presented:
External USB audio card with optical S/PDIF POF interface - [Link]
techshopdude @ instructables.com writes:
There are many electronic devices that use the SPI bus, or Serial Peripheral Interface bus, for communications (e.g. various sensors, LCD displays, digital potentiometers, D/A and A/D converters, wireless transmitters and receivers, audio volume controls). The devices receive data serially from a microcontroller using a 3-wire set-up that includes a chip select signal (usually titled CS – when this signal is at logic 0, a chip recognizes it will be receiving or sending data), a clock signal for clocking the serial data into the device, and the serial data stream itself.
Using an Arduino to Control or Test an SPI electronic device - [Link]
If you have embarked upon electronics projects in the past, there is a good chance you have already encountered this common component and soldered into your circuit without second thought. Diodes are valuable in electronics and serve a variety of purposes, which will be highlighted in upcoming steps.
How-To: Diodes - [Link]