I NEED TO FIND CABLE MICRO USB(SMARTPHONE) TO Serial Communication(RX/TX) TO SEND SMS WITH
arduino MEGA 1280
Stop SHOUTING.
You can't connect usb directly to the Arduino's serial pins.
SO HOW CAN I CONECT MY SMARTPHONE TO THE TX/RX AND NOT WITH BT
Is your shift key or caps lock key stuck?
Which smart phone do you have?
ANDROID PHONE SGS
Seriously, quit with the BLOCK CAPITALS.
You could use a USB host shield, and the Android ADK.