Just a quick one.
I recently bought a Bluetooth
module for my future projects named BC4 L6 from ebay. It allows transparent RS232 communication using bluetooth. The module is 3.3V,
but most of my projects are 5V.
Here is small breakout board with TTL converter (3V3 to 5V) and 2x LEDs (1 for status and 1 for pairing)
Module is tested and working fine. It might be handy for someone who bought the same one. The six pin header match the FTDI breakout.
Note: The MOSFET converter can be on the RX line replaced with voltage divider.