This tutorial describes in very detail about the basic structure of a monochrome LED dot matrix and how static characters and special symbols are displayed on it with a microcontroller.
Basics of LED dot matrix display – [Link]
While reading through Charles Platt’s excellent book Make: Electronics, I came across this nice little circuit for making a gentle pulsing LED. I built it for fun, and was struck by the “humanness” of the pulse, but couldn’t figure out what to do with it. Later I found a heart-shaped tag on some pants I had bought, and well, this is the result. I opted to use mainly scrap parts salvaged from various sources. I liked the hacky recycled feel that gave it.
I took Charles’ circuit, and added a second LED for some symmetry. The bob under the pendant is the power source. The pendant’s chain is part of the circuit, so the clasp becomes the on-off switch.
Beating Heart LED Pendant – [Link]
Using a pair of matched transistors to translate a high-side current-sense signal down to a ground reference, this circuit lets you parallel LED-driver circuits as required to achieve the desired drive current.
App note: Parallel LED drivers for maximum current – [Link]
This driver is used in LED replacement lamps for MR16 halogen bulb sockets. It’s compatible with common dimmers:
The MAX16840, an LED driver that employs a proprietary architecture to ensure flicker-free, dimmable operation with electronic transformers and cut-angle dimmers. Maxim’s patent-pending approach enables the design of retrofit LED lamps that can replace halogen MR16s without any changes to the existing electrical infrastructure. This removes an important obstacle to commercial viability, allowing end users to enjoy all the benefits of LED lighting with substantially lower deployment costs.
Chip powers LED lamps in MR16 halogen bulb systems – [Link]
Jon Chandler explorers the often overlooked calculations behind selecting the right resistor for an LED. This somewhat simple task is taken for granted by many, although it’s a world of mystery for others.
Got an LED and have no idea what resistor to use with it? Jon covers it step by step.
LED Calculations – [Link]
Propeller clocks are nothing new to anyone who has been into electronics for a while. They use an idea called POV, Persistence Of Vision, which means that if something appears in the same spot consistently, at least 50-60 times per second, our brains think that it’s permanently there when it really is not. TV’s and Monitors use this method of display, so it’s not as uncommon as you might think.
After having seen so many propeller clock POV videos on Youtube, but no real description of how they work or how to build your own, I set out to make one and document how it was built. The Pyro Propeller Clock POV design criteria was short and sweet: be as simple as possible in order to encourage others to make their own, DIY style.
Pyro Propeller Clock POV – [Link]
This project creates a RGB LED lit love heart which is controlled by a PIC12F683 microcontroller. I designed the project as a gift for my wife on our 15th wedding anniversary (since she puts up with my addiction to electronics I thought she deserved something in return!).
RGB LED Love Heart – [Link]
Step by step instructions for how to build and implement the replacement surgical lamp bulb system using an LED circuit developed by Mohammed Shafir and Zoe Englander as part of the course BME 262-Design for the Developing World at the Pratt School of Engineering, Duke University.
Replacement for surgical lamp bulbs using LED circuit – [Link]
In this project it was used the “Piranha Super-flux RGB” Led of common anode, and the PIC18F25K20, in order to generate combinations of colors. It has two function modes, automatic that generate the color sequence that is stored in the μC memory, and the manual mode in which you can select one of the seven possible colors.
Super Flux RGB LED Controller – [Link]
plastibots.com writes: [via]
I’ve been involved in microcontrollers for some time – but of the LEGO Mindstorms flavour (and BASIC Stamp to a lesser extent). Lately, I’ve jumped on the Arduino bandwagon. I’ve always had the natural nack to fix pretty much anything that has batteries or a plug running out of it. As the Arduino revolution has picked up dramatically over the past few years, so to has my desire to do DIY projects around the house. At some point in the future, we plan a kitchen reno. Part of that reno will the addition of under-cabinet LED lighting. Since that is far off, but I also had the need for better lighting in my office, I figured this would be a great time to proto something for the kitchen upgrade, while making something functional for the office. So, here it is..
Dual LED Desk Light Controller – [Link]