UART problem in rate of it

HGHK · Joined: 29 Jun 2010 Posts: 33

I need UART communication and I use 32.768KHz crystal for PIC16F876. I set 9600 baud rate. But my compiler report me an error about it. Please help me ASAP.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

See this thread about the Picbaud program:
http://www.ccsinfo.com/forum/viewtopic.php?t=37250

Ttelmah · Joined: 11 Mar 2010 Posts: 19552

And, 'think about it' for a moment. The UART divider is fed from the master clock/4. 32768/4 = 8192. What 'hope' is there to generate a clock at 9600Hz, by then dividing this...
You simply have no hope of operating at 9600bps, from a 32768 crystal. Now, if you switched to 38400Hz for your crystal, you might be able to get things working, but even then, you are going to need huge gaps between the characters, since it takes several dozen machine cycles to process a character...
You need more processor speed to have any chance of getting this to work.

Best Wishes