First, we'll change the baud rate as described by Oscar. Use this link if you're using an Arduino to change the baud.
Using my cool CP102 USB to UART adapter, I tried following the directions from painless360, summarized below, but I couldn't change my com port. Turns out you need to run Arduino as an administrator to change the COM port. Also those commands are for the new HC-06.
Here is another great guide I used, specific to the HC-05 I ordered.
The HC-05 is different from the HC-06 in 2 respects, it requires the button be depressed when powering on to go into AT mode and it wants both NL and CR sent with the command. Also, my UART to USB adapter has the option of 3 or 5v. 3v didn't work, so I had to use 5v.
Plug it in
Open the Arduino Studio
Open the serial Monitor
Pick "Both NL & CR"
Set serial monitor BAUD to 9600
ATcommand with every BAUD until you find the right one.
AT+UARTcommand, which returns the BAUD, showed that it was running 9600,0,0. Edit: This is for non-AT mode.
Change BAUD enter
AT+UART=115200,1,0 where 1 is the stop bit and 0 is the parity. On the HC-06 the command is just
AT+BAUD8 More documentation for the HC-05 is available at iteadsstudio.com
It should say
OK on the HC-05,
OK115200 on the HC-06
This will change the BAUD in bluetooth mode, not the baud in AT mode, so your connection should remain open
Change the name, on the HC-05
AT+NAME? doesnt seem to work
Check the pin with
AT+ PSWD? and set it with
AT+ PSWD=0000 where 0000 is your pin
AT+PIN1234for the HC-06
If you're using a cc3d like me, here's how you wire it onto your copter