RS232 To TTL Converter Module MAX3232
This module can be used to convert the RS232 voltage of PC to TTL voltage that used by microcontroller. Directly plug the DB9 connector your PC then you can communicate with the microcontrollers using the Serial port. It is applicable to a variety of platforms including Arduino / AVR / ARM. For Arduino, please also note that there is already a UART2USB connection, you just need this module if you want more serial connection to your computer.