Microcontroller

Try using a search engine. According to my quick search for what you mean by LDR, I came up with the following:

Louisana Department of Revenue

LDR Industries

Long Distance Relationships

Luci della Ribalta

Lutherian Disaster Response

and Light Dependent Resistor

It might be helpfull if you indicated what you mean. As for the possibilities for microcontrollers, there are thousands available.

Among the thousands of microcontrollers, there are many examples of how to do this completely free to you. You just have to be a little more specific to get what you want. Most of the time the hardest part of finding something is to figure out what it is called. You might search for "solar tracking" and the type of controller you want to use. As you read, you might see other terms that will make good search phrases.

LDR - light dependent resistor..... am doing project on solar tracking sys... I am using LDR for this.... as we know that the sun moves 15 degree per hour,so am gonna track the sun by using ldr and i need to rotate the solar panel for 15 degree after one hr reached by the sun.... so by this way we can keep on track the sun..... I need a stepper motor program for interfacing with microcontroller .... and that motor must be programmed to rotate the solar panel for 15 degree for every one hour.... can u help me on this?

This should get you started... microcontroller sun tracking

http://bit.ly/HlW0zt