Level shifters are able to convert a low voltage to a high voltage. MAX232 is a level shifter which translates voltages so that your micrcontroller can talk to your PC through an RS-232 port. This translates between the 0 to 5V TTL level voltages to the /-12V levels required by RS-232. These ICs come in DIP package making them suitable for breadboard prototyping. Documents Maxim MAX232 Datasheet Tutorial about RS-232 and translation by Sparkfun Electronics Related
