shift left? shift right?

[rayferd2]

hi everyone, this is my first post.

I'm not a total noob to C but my skills are rusty....it's been a while.

Here is what I have:

BYTE cin[133];
WORD msg[66];
.
.
where cin holds the values read from the serial port. the box I'm writing code for only reads one char at a time from the port. I want to take this data and map it over to a WORD as follows:

lets say cin[0]=FF and cin[1] =AC.....I want msg[0]=FFAC.

help?

 

[Salem]

lets say cin[0]=FF and cin[1] =AC.....I want msg[0]=FFAC.

Try

msg[0] = (((WORD)cin[0])<< 8 ) | cin[1];

 

[dlkfjdlkfjdlfkd]

There aren't any BYTE or WORD types in C. But assuming that BYTE is unsigned char and WORD is unsigned int:

msg[0] = cin[0] << 8 | cin[1];

 

[rayferd2]

Thanks, that worked perfectly!!

 

[lionelhill]

Just do remember that the consequences of what you are doing are different in apples to PCs. If you are doing this on a PC, you are swapping the byte order, since a PC expects the low byte first, high byte second, whereas you're interpreting your data mac-way-round.