problem with getch an rs232

[alfonsol]

i'm tryin to make a menu, but always it executes the last IF

if (orden!='C'){
pila=150;
(int32)deltap=9000

i can send an A, B or C, but the program always executes the last if.

here is the code.

orden=getch();
if (orden!='A') {
pila=60;
(int32)deltap=2000;
}
if (orden!='B'){
pila=330;
(int32)deltap=9000;
}
if (orden!='C'){
pila=150;
(int32)deltap=9000;

[PCM programmer]

Post a small program that shows the problem.
1. Show all variable declarations.
2. Show your #use rs232() statement, etc.
3. Post your version of the compiler.

[sonicdeejay]

I use Max 232 to buffer between my PIC..that's connection works for me...and my RS232 code is

[Ttelmah]

As written, the code will always execute the last if, unless the character is a 'C' (also remember that if you type a 'C', by default this will be lower case, and will not be accepted).
As it stands, if 'A' arrives, it'll execute the pila=330 code, then the pila=150 code. If 'B' arrives, it'll execute the pila=60 code, and then the pila=150 code. If 'C' arrives, it'll execute the pila=60 code, then the pila=330 code. If anything else arrives, all three statements will execute.
Normally you would test for the character beng equal, rather than 'not equal', and also use the 'else' statement, so it only executes the other tests if the tests so far have failed.

Best Wishes

[alfonsol]

include <18F1320.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=10000000)
#use rs232(baud=9600, xmit=PIN_b1, rcv=PIN_b4)

char orden;
int32 pila,deltap;

main(void)
{
orden=getch();
if (orden!='A') {
pila=60;
(int32)deltap=2000;
}
if (orden!='B'){
pila=330;
(int32)deltap=9000;
}
if (orden!='C'){
pila=150;
(int32)deltap=9000;

}
printf("\n\rorde: %4c pila: %4ld deltap: %4ld \n\r",orden,pila,deltap);
}

this program shows what happens

[SherpaDoug]

It seems this should wait for a character, then execute two of the three options depending what the character is, or all three if it is an unknown character. Is this what you want to happen? What do you want this code to do?

Offhand i would say the <if (orden!='A')> is a little odd for a menu. It means that that section of code will execute if anything EXCEPT 'A' comes in. < if (orden ='A')> is more what I would expect.
_________________
The search for better is endless. Instead simply find very good and get the job done.

[dbotkin]

Sonicdeejay: Here's a little easier and much cheaper way to do it:



You can use 10K resistors in place of the 2.2K. Complete details at http://www.botkin.org/dale/rs232_interface.htm if you want to read it.

Dale

[sonicdeejay]

[alfonsol]

thanks the problem was i used != and i should used == i copied the line from another program and i didn't see that