Change Baud rate

10gigbill

I am building a serial test generator to send out serial commands. I would like to have several baud rates (say from reading a dip sw) Since "Baud" is a constant, how do I get around this? (without writing different subs for each baud rate)

PJAllen

It doesn't have to be a CONstant.
It could be a variable.

baudrate var Word

baudrate = 9600
SEROUT Sio, Baudrate, ["Bingo!"]

baudrate = 4800
SEROUT Sio, Baudrate, ["Bango!"]

wass

The SX/B manual says that the baud rate does have to be a constant, am I missing something?

While I've never tried this, take a look in the manual at the second example in the INTERRUPT command. It shows how to receive into a buffer using ASM code. It further shows the baud rate as a constant, but it would not be hard to modify this for a variable baud rate and for sedning instead of receiving. There are all SX library returns for complete UART functionality and a lot more here:

http://www.piclist.com/techref/scenix/lib/io/osi2/serial/rs232_sx.htm

10gigbill

I tried a var and get an error. It seems baud has to be a string constant. must be some way to change baud rate on the fly....?

PJAllen

OK, sorry, I haven't spent any time on SX/B since last summer.
I was looking at my XBee remote control programming from then.
The baudrate doesn't have to be a declared CONstant (it's a "string constant").

SEROUT xmt_pin, T9600, "!"

The value to be transmitted, that in quotes, could be a byte variable instead.

Read your DIP switches before you transmit and branch to a FUNC or SUB with the desired baudmode plugged in?

sending:
  xmtbyte = $F0

  IF dipsw = 0 GOTO lowbps
  GOTO highbps   ' =1

lowbps:
  SEROUT xmtpin, T2400, xmtbyte
  GOTO sending
highbps:
  SEROUT xmtpin, T9600, xmtbyte
  GOTO sending

10gigbill

Thanks P J

I think that might be the way to go. I'll plug that in and see.

Bill