Hi,

I've seen auto baud rate detection in 'smart' rs232 Y cables, that let you
connect  a barcode reader to a rs232 connection between a terminal and a
host.
You put the Y cable in autodetect mode and then type UTUT at the terminal
prompt. If you notice U is 0x55 and T 0x54 in ASCII. So an U is a sequence
of low-high with bit duration. I presume thr microcontroller in the cable
counts the duration of the low-highs and then sets the correct baud rate.

Well this system isn't truly automatic, since you need to put it into
autodetect mode, but it's the closest thing I've seen.

Pedro Machado
pedrom@burotica.pt
 ----------
From: owner-piclist
To: Multiple recipients of list PICLIST
Subject: Auto bauding
Date: Tue, 96 de 10 de 15 10:39

Hi,

Does anyone have any ideas for implementing auto baud rate detection
on the PIC16C73.  I don't want any switches hanging off my device and
would like it to detect the baud rate anything between 1200 and 57600.

I suppose I could just measure the width of the start bit & calculate
the appropriate baud rate.  But this will not work when changing the
baud rate without powering the device do.

Any ideas would be greatly appreciated.  Or better still a pointer to
any exising code if someone has any?

TIA
Maurice