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pic18f252 usart char

Started by Unknown December 29, 2003
hi all
can the USART of PIC 18f252 transmit only signed char or does it even
transmit unsigned char.
i am checking the serial communication by sending a few HEX values through
the PIC through a MAX232 to my PC,but when i send hex values above 0x80
ie(128 d) i donot get the desired byte on my PC.
waiting for an reply anxiously

krishna
--------------------------------
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Check to make sure you are using 8-bit no parity settings on the USART of both the PC and PIC.  I can't speak for the 18F252, as I've not used it, but the pic's I've used will do 8-bit no parity just fine.  If you are using 7-bit with parity, then you can't do unsigned chars as they won't fit in 7 bits, and the USART will chop off the 8th bit and replace it with the parity bit.
----- Original Message -----
From: k...@microtechnologies.net
To: p...@yahoogroups.com
Sent: Monday, December 29, 2003 1:37 PM
Subject: [piclist] pic18f252 usart char

hi all
can the USART of PIC 18f252 transmit only signed char or does it even
transmit unsigned char.
i am checking the serial communication by sending a few HEX values through
the PIC through a MAX232 to my PC,but when i send hex values above 0x80
ie(128 d) i donot get the desired byte on my PC.
waiting for an reply anxiously

krishna
--------------------------------
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http://mail2web.com/ .


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also, check the pc side of things. some serial I/O libraries whack
the 8th bit. there is nothing in the PIC USART that precludes 8 bit
I/O.

--- In , "Bert Drake" <Bert@D...> wrote:
> Check to make sure you are using 8-bit no parity settings on the
USART of both the PC and PIC. I can't speak for the 18F252, as I've
not used it, but the pic's I've used will do 8-bit no parity just
fine. If you are using 7-bit with parity, then you can't do unsigned
chars as they won't fit in 7 bits, and the USART will chop off the
8th bit and replace it with the parity bit.
> ----- Original Message -----
> From: krishnap@m...
> To:
> Sent: Monday, December 29, 2003 1:37 PM
> Subject: [piclist] pic18f252 usart char > hi all
> can the USART of PIC 18f252 transmit only signed char or does it
even
> transmit unsigned char.
> i am checking the serial communication by sending a few HEX
values through
> the PIC through a MAX232 to my PC,but when i send hex values
above 0x80
> ie(128 d) i donot get the desired byte on my PC.
> waiting for an reply anxiously
>
> krishna >
> ------------------------------
--
> mail2web - Check your email from the web at
> http://mail2web.com/ . >
>
> to unsubscribe, go to http://www.yahoogroups.com and follow the
instructions
>
>
> --------------------------------
----------
> Yahoo! Groups Links
>
> a.. To





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