On Fri, Mar 27, 2009 at 4:31 PM, Graham Davies <ecros...@ecrostech.com>wrote:
> David VanHorn wrote: > "Ok, so that leaves me VERY confused." > Maybe it would help to think about logic levels in simulation. The three > basic levels are "low", "high" and "unknown". The three variations of the > char type are similar, signed, unsigned and unspecified. I think that the > reason the unspecified variant of char got into the C language definition > was political, not technical. The other basic integer types don't share > this quirk. > Right, the unspecified variant looks like a disaster waiting to happen, IMHO. > The compiler is probably warning you because a signed char and an > unsigned char are both different from an unspecified or plain char, just > like low and high are different from unknown. > Ok, but using the portable types, there does not appear to be an unspecified char, which seems like a very good idea to me. > The reason that a function would take a char of unspecified signedness is > that the writer of the function reasons that only the least significant > seven bits mean anything, so why bother with what the MSB does. I think > it's kind-of traditional that 7-bit ASCII is represented as a plain char. > Personally, I use uint8_t. > Right, and that's what makes the most sense to me, ASCII is unsigned, so unsigned char should be right, but the routine apparently requires signed! Previously, I was using the "unsigned char" and "signed char" forms, and the "unsigned char" form gave me warnings.. So I used "signed char", which satisfied the compiler... Now I'm in the situation where I can't seem to satisfy it with signed or unsigned, in the "uint8_t" and "int_t" forms. I don't want to cast aspersions, but it seems to me like lcd_puts is buggy, if it's requiring sign. > Graham. > > > _______________________________________________ > AVR-GCC-list mailing list > AVR-GCC-list@nongnu.org > http://lists.nongnu.org/mailman/listinfo/avr-gcc-list > > -- David VanHorn Hardware Engineer MobileFusion, Inc 2715 Sarah St Pittsburgh PA, 15203 Phone: (001) 412-481-1111 Cell: (001) 765-215-8521 Fax: (001) 412-481-0220 d...@mobilefusioninc.com www.mobilefusioninc.com **************************************************************************** This communication (including any attachments) is for the use of the intended recipient(s) only and may contain information that is confidential, privileged or otherwise legally protected. Any unauthorized use or dissemination of this communication is prohibited. If you have received this communication in error, please immediately notify the sender by return e-mail message and delete all copies of the original communication. Thank you for your cooperation. ****************************************************************************
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