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Message |
Guest
Guest
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| problem with switch on picdem DBoard |
 Posted: Sat Feb 04, 2006 11:40 am |
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I have PU switch and i use PIN A4. The MCU is 16F84A.
If i run my code :
| Code: |
#define P_0 PORTA,4
#define TRISP_0 TRISA,4
int tipkaPRESSED()
{
static int1 laststate=0;
if (!bit_test(* P_0) ) {
delay_ms(50);
if (laststate) {
laststate = 0;
return(1);
}
} else
laststate=1;
return (0);
} |
i get compiler error :
1.) Condition always FALSE PORTA
2.) Undefined identifier
He ??
Ports are defined and pointed to A4. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sat Feb 04, 2006 1:35 pm |
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Port i/o is easier if you use the CCS functions such as:
input()
output_low()
output_high()
If you use the CCS "standard i/o" mode (which is the default mode of
the compiler) then you don't have to set the TRIS for these functions.
The compiler will do it for you automatically.
I've changed your program to use the input() function.
See the lines shown in bold below:
| Quote: | #define P_0 PIN_A4
int tipkaPRESSED()
{
static int1 laststate=0;
if (!input(P_0)) {
delay_ms(50);
if (laststate) {
laststate = 0;
return(1);
}
} else
laststate=1;
return (0);
} |
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Guest
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| Posted: Sun Feb 05, 2006 5:06 am |
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Thank you, it partly is working.
1.) If i want to use "my way", can i define this in compiler ?
2.) Im asking this becuse, then i have to change parts where im using ASM:
(is there any function in CCS so i can avoid ASM ? ).
| Code: | void START_tipka() {
#asm
BSF _RP0
BSF TRISP_0
#endasm
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sun Feb 05, 2006 5:27 am |
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You can use a #byte statement to declare PortA to be a variable
at memory address 0x05. Then you can use PortA as a parameter
in the bit_test() function. Example:
| Quote: |
#byte PortA = 5
int tipkaPRESSED()
{
static int1 laststate=0;
if (!bit_test(PortA, 4) ) {
delay_ms(50);
if (laststate) {
laststate = 0;
return(1);
}
} else
laststate=1;
return (0);
} |
If you want to set the TRIS, then use the set_tris_a() function.
Though, you could also use a #byte statement to declare the
address of the TRISA register, and then access it directly. |
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Guest
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| Posted: Sun Feb 05, 2006 6:14 am |
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| Code: | #define TRISP_0 TRISA,4
void START_tipka()
{
#asm
BSF _RP0
BSF TRISP_0
#endasm |
Please explain me this part... As far as i know, CCS supports ASM parts.
But when i want to run the initialisation part for button then i get compiler message: Undefined identifier TRISA
I saw that you have written :
| Quote: | | If you want to set the TRIS, then use the set_tris_a() function. |
Is this a MUST or can i use ASM for such jobs... |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sun Feb 05, 2006 2:17 pm |
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You shouldn't mix ASM and C in the way that you're doing it.
Also, it looks to me like you came from a different PIC C compiler.
You were previously using one that doesn't have all the capabilities
of CCS, perhaps, so you're trying to do all sorts of low level coding
that you believe must be done.
You don't have to do that with CCS. You don't have to set RP0,
or the bank select registers. You don't have to manually assign
memory addresses or banks to your variables. It's all done
automatically for you. This is one of the reasons why people use CCS.
With regard to your specific question, CCS doesn't have a predefined
header file with all the register addresses. You either have to do it
yourself or find one of the register header files that have been posted
around the forum, usually in the Code Library forum.
The following program will show you how to use the #bit directive
to declare the address of a bit.
| Quote: | #include <16F877.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=4000000)
#bit TRISP_0 = 0x85.4
//=========================
void main()
{
#asm
BSF TRISP_0
#endasm
while(1);
} |
The CCS Assembler has several limitations, and these are discussed
on here fairly often by Ttelmah. It's not the same as MPASM. If you
want to use CCS as a "shell" to do assembler, it's not the best idea. |
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Guest
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| Posted: Tue Feb 07, 2006 6:50 am |
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| Code: |
#byte PortA = 5
#bit TRISP_0 = 0x85.4
int tipkaPRESSED()
{
static int1 laststate=0;
if (!bit_test(PortA, 4) ) {
delay_ms(50);
if (laststate) {
laststate = 0;
return(1);
}
} else
laststate=1;
return (0);
}
//-------------------------------------
void STARTtipka() // initialisation
{
#asm
BSF TRISP_0
#endasm
}
main()
{
STARTtipka();
if ( tipkaPRESSED())
output_high(PIN_B0);
}
|
Before i get further please explain me this: this is the code that should trigger the button state and i think that i write it OK. Wenn i run the code, press the switch,nothing happens. There is no compiler errors.
This has nothing to do with ASM ? ( just to be sure before i start changes :-)) |
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Guest
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| Posted: Tue Feb 07, 2006 6:52 am |
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| Code: |
#byte PortA = 5
#bit TRISP_0 = 0x85.4
int tipkaPRESSED()
{
static int1 laststate=0;
if (!bit_test(PortA, 4) ) {
delay_ms(50);
if (laststate) {
laststate = 0;
return(1);
}
} else
laststate=1;
return (0);
}
//-------------------------------------
void STARTtipka() // initialisation
{
#asm
BSF TRISP_0
#endasm
}
main()
{
STARTtipka();
if ( tipkaPRESSED())
output_high(PIN_B0);
}
|
Before i get further please explain me this: this is the code that should trigger the button state and i think that i write it OK. Wenn i run the code, press the switch,nothing happens. There is no compiler errors.
This has nothing to do with ASM ? ( just to be sure before i start changes :-)) |
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Guest
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| Posted: Tue Feb 07, 2006 7:10 am |
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| Code: |
main()
{
while(){
STARTtipka();
if ( tipkaPRESSED())
output_high(PIN_B0);
}
} |
My mistake. Sorry! |
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