Ive been spending some time familiarizing myself with the RN52 bluetooth module from microchip.
The footprint of the RN52 does not lend itself to mounting a breadboard or proto board with ease - but none the less its possible to connect up enough pins to get it work
The USB to serial device I had on hand was set for 5V while the RN52 requires 3.3V The ebay special adapter appears to be a fake PL2303 (cheap and no markings) to convert the UART to 3.3V i lifted PIN20 (UART VDD) and tied it to the 3.3V reg output.
Connecting GPIO9 (Pin11) to ground puts the RN52 in CMD mode. using a Serial Terminal program it is possible to interegate the RN52 and retrieve various items of data from it.