|
From: | Dave Hansen |
Subject: | Re: [avr-gcc-list] Small program for UART not working |
Date: | Mon, 12 Sep 2005 14:55:11 -0400 |
From: "Anton Erasmus" <address@hidden> [...]
> I tried to calculate the baud rate on scope, I found I > can't get a exactly number, I can only get an > estimate. Do you know if there's way to set the baud > rate accurately? Send 0xAA continiously. That way you get a nice square wave at the baud rate frequency. If you drop
I thought it was 0x55 (or ASCII 'U') that you wanted, rather than 0xAA.An idle RS-232 line is in the "Mark" state. Start bit is "Mark" to "Space" transition. Data bits are then sent LSB first, with "Mark" == 1, "Space" == 0, so the LSB has to be a '1'. After the last databit (bit 7 is zero, or "Space"), the stop bit puts the line back into idle ("Mark") for 1 bit time.
This should work for 8N1. Regards, -=Dave
[Prev in Thread] | Current Thread | [Next in Thread] |