Jan-Erik Soderholm wrote:

>Laszlo Zsolt Nagy wrote :
>
>  
>
>>I have a PIC18LF452, connected to my computer on the COM1 
>>port (using a MAX232 to interface between the USART and the
>>serial line). CLK = 32MHz, and I'm using 56700 bps speed.
>>(Relative baud rate error is about 2%.)
>>    
>>
>
>2 % is a *little* to much. Try to stay within +/- 1 %.
>  
>
It is not possible at 32MHz. I need speed both on the USART and in the PIC.
I will try 40MHz, that will be 0.2% error. (Just I do not have a 40MHz 
crystal at hand.)

>Does it work at a slower speed ? Like 9600 ?
>  
>
Good question. Trying...

>>The simplest program I could create: read a byte from the
>>USART port, add 16 and then write it back (in an infinite loop).
>>    
>>
>
>That is *not* the "simplest program" you can create !
>
>Start with only one direction. Send a hardcoded value
>from the PIC to the PC and get that working first.
>  
>
Ok. Good idea. Thanks. :-)

>>On the computer's side, there is a Windows application, 
>>sending out the byte '255' continuously.
>>    
>>
>
>And what do you *expect* in return ?
>  
>
(255 + 16) mod 256 = 15 = 00000111b
This is what I expect. Regarding the bit pattern, what I get is similar.

Thanks, I'll try what you suggested.

   Les

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