Davide Gironi writes: This circuit is a Drum Light Trigger. It uses a piezo transducer that reacts to drum vibration, and a NE555 timer to setup the light time. There are two trimmer pot, one to setup the sensibility of the vibration, the other to set how long the LED light will be active. This […]
Another Instructable by Jan Henrik, a constant-current source which gives 20mA at the output. He writes: It is a circuit, which limits the current to 20mA, what allows us to drive any normal led, without calculating a resistor, you can just plug the led in and see it emitting light… Also this allows us to test […]
Luca Dentella has published his latest project: BlueMatrix. It’s a portable LED matrix display based on Arduino Uno, powered by a Lipo battery and connected via Bluetooth to a personal computer or an Android smartphone. I’ve also developed the controlling app for Android, available on Google’s PlayStore. All the schematics, source files, inkscape files for […]
Raj of Embedded Lab has a series of chipKIT tutorials. This 5th project will show you how to build a digital stopwatch on seven segment LED display with the chipKIT Uno32: In this project, we will use the chipKIT Uno32 board to build a digital stopwatch capable of timing minutes, seconds, and 1/10th of seconds, and with a […]
In this video Julian Ilett demonstrates his DIY 100W LED flashlight: 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 […]
Iamzxlee has written an article detailing his colour sensor 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 […]
Scott Harden writes: I came across the need for a quick and dirty display to show a 4 digit number from a microcontroller. The right way to do this would be to use a microcontroller in combination with a collection of transistors and current limiting resistors, or even a dedicated 7-segment LED driver IC. The […]
TomKeddie writes: Based on a recommendation in these forums I bought an American Optical 570 stereo microscope on ebay some time back. I added the illumination shown below, I thought it might be useful to others. I cut 3 pieces from a right angle piece of aluminium section, coated them in heatshrink, attached them to […]
Peter over at Electronics-Lab posted an article describing how he designed and built his simple SMD LED tester: This project is a simple LED tester and LED polarity checker. It can be used to check 1206, 0805, 0603 and 5mm LEDs. All parts are readily available and they are very cheap. Usage is very simple. Just press the […]
cpldcpu writes: What’s pretty cool about these LEDs is that they are diffuse – no more blinding unidirectional light. This might be very useful for indicator lights. Furthermore, you can easily wire them freeform without a pcb. I see a lot of RGB LED cubes coming up… The LEDs come with four leads: VCC, GND, […]
Kevin Rye built this Night Light 2.0: And there it is. Definitely not my best work, but it’ll do. I just wanted to use up that last PCB left over from the Tesseract build. I guess it was better to use the PCB for something rather than have it sitting in a parts drawer. I imagined the entire […]
Ray Wang writes about his recently completed project, the SquareWear Mini with All-New Chainable Color LED Matrix, and an Interactive Animation Design Tool. The goal is to make standalone programmable color display gadgets. The LED matrix is chainable and can be seamlessly extended in both X and Y directions. The SquareWear Mini is essentially an […]
Michael Beyhs shows us how to use an LED as a sensor: How the code works: Configure all analog inputs to outputs and pull low to turn on all red LEDs. Turn one analog input pin into an actual Input and read the amount of light that is reflected into it. Turn that input back into […]
As Valentines day is fast approaching, many are thinking of a wonderful present to their love ones. Tom built this heart-shaped LED chaser and wrote a post on his blog detailing it’s assembly: The object of your desire will not be able to resist a heart-shaped LED chaser, lovingly hand-crafted on perfboard with a CD4017B decade counter […]
Nick Leijenhorst writes: I wanted to dim my room LED lighting with a potentiometer, and decided on creating a solution from scratch to make it more fun and educative. I decided to go with the fairly well-known 555 PWM circuit. To decrease size and for learning purposes I decided on using surface-mount components for the […]
Davide Gironi blogged about his LED matrix mask built on AVR ATmega8: avr_mask1 wish you a Merry Christmas and a Happy New Year! AVR Mask1 is a led mask built around 74hc595 shift register and 8×8 led matrix, running on an ATMega8 microcontroller.
Kevin Rye posted an update on his Tesseract, we wrote about it previously. With the software and hardware for the Tesseract complete, it was time to wrap up the enclosure.
Kevin Rye documented his Tesseract build. Check out the project’s Part II.
Dilshan Jayakody wrote a post on his blog about his 3W constant current LED driver: This is quick post about 3W constant current LED driver which I was design to combine with some homemade furniture piece. The main components of this system is LM311 voltage comparator and IRF9640 P-Channel MOSFET. This module is design to drive maximum of […]
Rupert Hirst writes, “After the success using the Midas MCOB21605G1V 1602 OLED display in my previous article. My next challenge would be connecting the module to my i2C backpack custom PCB, Using the PCF8574 i2c IC”