Features:

This module requires a 3.3 volt supply for VCC, and 3.3V logic.
Connecting RX or TX on 5V Arduino will destroy this module.
You must use a logic level converter, or a 3.3V Arduino.
The 3.3V supply on the Arduino Uno has inadequate current capability to power this module.
You must provide a separate, higher 3.3V supply(about 300mA or better).