This doesn't work:
unsigned char foo; foo = 0x123; sprintf("the unsigned value is:%c",foo);
I get this error:
cannot convert parameter 2 from 'unsigned char' to 'char'
printf() formta string's
Before you go off looking at unsigned chars causing the problem, take a closer look at this line:
sprintf("the unsigned value is:%c",foo);
The first argument of sprintf is always the string to which the value will be printed. That line should look something like:
sprintf(str, "the unsigned value is:%c",foo);
Unless you meant printf instead of sprintf.
After fixing that, you can use %u in your format string to print out the value of an unsigned type.