ladyada.net has write a new article on how to use LEDs for people making their first steps on electronics. It talks about LED polarity, the various kinds of LEDs, what are LEDs used for, changing the brightness with resistors, changing the brightness with voltage, learn how to calculate the current limiting resistor etc.
How to use LEDs introduction- [Link]
This project shows how to build your own LED ring light. “Alan” bought a stereo microscope from ebay and wanted a powerful light source, so he machined one using a lathe. The light ring comprise of SMD LEDs and a block of lexan. He machined it to include slots for the LEDs as well as the microscope mount. Check photos and construction details on the link below.
Make your own Ring Light – [Link]
This article discuss about the 555 timer IC. It talks about the history of it, the modes of operation (Monostable, Astable and Bistable), the pinout etc. It also introduces a LED blinker circuit to show it in operation.
555 Timer IC – [Link]
This project is a LED speedometer based on LM2917 frequency to voltage converter. It has a fixed sensor over a rotating toothed ferrous wheel. As the teeth pass by the sensor, up & down electrical impulses are generated, as the speed increases, the frequency goes up too. Then the frequency is converted to voltage using LM2917 and that voltage will drive 30 LEDs through 3x LM3914 ICs.
LED Speedometer – [Link]
This project is a great little idea based on LED. It uses a LED and a push button to make a LED push button switch that can easily mounted on your project box. To achieve that you need a smooth flat surface at the bottom of the LED and that can be made using some hot glue and a knife as seen on the page below.
A LED Pushbutton – [Link]
This project is a 8×8 LED matrix controlled by an Arduino using 4 shift registers. The shift registers are 8-bit wide and are easily interfaced with the SPI protocol. Pulse width modulation is used to mix the colors.
8×8 RGB LED Matrix – [Link]
This project consists of LED strips mounted on an outdoor trellace which functions as a lightning simulator, outdoor breathalyzer, graphic equalizer synced to music, and a few other effects with sound. The system is controller by an Arduino. [via]
The Lightning Simulator / Breathalyzer / Graphic Equalizer – [Link]
This project is a very small virtual rotating led beacon build using 4 x 0603 SMD LEDs and it takes place of about 2,5 mm3. LEDs are controlled by a PIC12F629 and drives each led by a PWM signal. See the virtual rotating effect on the video above.
Virtual rotating LED beacon – [Link]