I wish to connect my Arduino BT to an external unit that requires RS-232 and I have a question regarding redefining the baud rate between the ATmega and the BT modem.
While it is not normally an issue connecting RS-232 equipment to the Arduino - you can solder together/buy a TTL <-> RS-232 interface and use SoftwareSerial for the communications - this external unit needs to be connected at a baud rate of 19200. And the SoftwareSerial library only guarantees stable operations at up to 9600 baud, which means that I can’t use SoftwareSerial for this specific project.
So I am thinking, what about connecting the external unit to the Arduino BT’s TX and RX pins? I know that the two units will share the same line, with all the funny things that may happen when you suddenly have both a BT modem and another unit listening in on the same data… I’ll have to worry about that when I get things connected
Anyway, using this approach would require me to lower the baud rate between the BT modem and the ATmega from 115200 to 19200. Will this pose any problems? I can see from the document http://www.arduino.cc/en/Main/ArduinoBTInitializationSketch that one should be able to define a custom baud rate, but I am not so keen on risking rendering my Arduino BT unusable by attempting to do so.
I look forward to hearing from you.