Arduino Wire.h Library !free! Link

Before Arduino, if you wanted to connect a microcontroller to a sensor, you entered a world of pain. You had to read datasheets that read like legal contracts. You had to manually toggle pins high and low, calculating precise timing delays in assembly or C. If you wanted to talk to a screen or a thermometer, you were essentially learning a new language for every single component.

Wire.beginTransmission(0x68); // Talk to device at address 0x68 Wire.write(0x00); // Tell it to look at register 0 Wire.endTransmission(); // Let go of the line arduino wire.h library