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 nice site called Robotbox is a community website for robot builders to show off their projects. It’s like an online portfolio for robot builders. The goals of the site are: 1) making it easy to find neat robots in one central location 2) making it easy to have a spot to show off all your robotic creations and 3) to inspire other builders with your projects. They have already 1000 registered members and over 200 robots so far.

This project is a temperature controller that controls the temperature of refrigerator and can regulate conditions for food and alcohol fermentations. It is based on ATmega48 microcontroller and includes a remote temperature sensor. It also has a relay to control the refrigerator. Check schematic and source code on the link below.

YATC – Yet Another Temperature Controller –[Link]

[Z]iyan and [Z]achery from the Rochester Institute of Technology are an excited bunch. They came up with a way to open their apartment door with a series of coded taps on their TI Chronos Watch. On the receiving end, at the door, a Ti CC1111 Eval Kit ( CC1111EMK868)  is in charge of opening the door when commanded by the watch.