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Leef_me
Joined: 14 Mar 2006
Posts: 45
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| trouble with CCP2 on B3 on PIC18F24k |
 Posted: Tue Dec 08, 2009 8:34 pm |
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I want to use B3 as the input to CCP2 configured as CCP_CAPTURE_FE.
In addition, I'd like to be able to poll the bit value.
This would make it a quasi "Interrupt on change" input that I could also poll.
The problem is being able to poll the B3 input after this instruction is executed. It is always low. 
| Code: | | setup_ccp2(CCP_CAPTURE_FE); |
RB0 is being used as another interrupt input
RB1,2,4 are PWM outputs
RB5 is a IOC button input
RB6 & 7 are left for ICD debugging only
Below is a test program.
Can anyone make suggestions on why the RB3 pin is read as 0 instead of in 'parallel' with the CCP2 input ?
| Code: |
//Compiler version 4.099
#include <18F24K20.h>
#device ICD=TRUE
#FUSES NODEBUG //No Debug mode for ICD
#device adc=8
#FUSES NOWDT // No Watch Dog Timer
#FUSES WDT128 //Watch Dog Timer uses 1:128 Postscale
#FUSES INTRC_IO //Internal RC Osc, no CLKOUT
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOWRT //Program memory not write protected
#FUSES NOWRTD //Data EEPROM not write protected
#FUSES IESO //Internal External Switch Over mode enabled
#FUSES FCMEN //Fail-safe clock monitor enabled
input channels on RESET
#FUSES LPT1OSC //Timer1 configured for low-power operation
#FUSES MCLR //Master Clear pin enabled
#FUSES NOXINST //Extended set extension and Indexed Addressing mode disabled (Legacy mode)
#FUSES NODELAYINTOSC
#FUSES CCP2B3 // enable the CCP2 pin to be used as a button input
//#FUSES PBADEN //PORTB pins are configured as analog #FUSES NOPBADEN //PORTB pins are configured as digital
#use delay(clock=1000000)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,stream=CONSOLE)
#BYTE STKPTR = 0xffc // stack pointer address, 2 msb are flags
#BYTE INTCON = 0xff2 //INTCON: INTERRUPT CONTROL REGISTER
#BYTE IOCB = 0xf7d // interrupt on change bit control
#byte LDR_WPUB = 0xF7C
#use fast_io(B)
int8 current, x;
int8 current2;
#int_RB
void RB_isr(void)
{
}
#int_CCP2
void CCP2_isr(void)
{
}
#int_EXT
void EXT_isr(void)
{
}
void main()
{
char key;
int16 duty;
IOCB = 0x20; // enable interrupt on change for RB5
ANSELH = 0;
setup_ccp1(CCP_OFF);
x=0;
disable_interrupts(GLOBAL);
clear_interrupt(INT_RB);
enable_interrupts(INT_RB);
// clear_interrupt(INT_EXT);
// enable_interrupts(INT_EXT);
clear_interrupt(INT_CCP2);
enable_interrupts(INT_CCP2);
/////////////////////////////////////////////////////////////////////
setup_ccp2(CCP_CAPTURE_FE); // don't care about value, just want the clock edge
// for use as button push detection
/////////////////////////////////////////////////////////////////////
set_tris_b(0b00101000); // RB5 & RB3 set these as inputs
port_b_pullups(TRUE); // bits 0, 3, 5 ; intr, up, dn
while(1)
{
fprintf(CONSOLE, "\r\nPress any key.");
key=fgetc(CONSOLE);
fputc(key,CONSOLE); // echo the pressed key
x++;
x++;
x++;
current=input(PIN_B3);
x++;
x++;
x++;
current2=input(PIN_B5);
x++;
x++;
x++;
fprintf(CONSOLE, "\r\n");
fprintf(CONSOLE, "%u",current);
fprintf(CONSOLE, " ");
fprintf(CONSOLE, "%u",current2);
}
} |
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Leef_me
Joined: 14 Mar 2006
Posts: 45
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| Posted: Wed Dec 09, 2009 3:39 pm |
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| bump |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Dec 09, 2009 3:51 pm |
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You want to test your theory of using another interrupt pin to detect a
level change event (i.e., to detect an edge). You have posted way too
much code for this test. You don't need all those interrupt routines. You
don't need all the x++ stuff. You don't need the #byte statements.
You don't need #fast io mode. The test could be done in 10 lines,
probably. That's why you're not getting an answer. Strip it down to
essentials. |
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Leef_me
Joined: 14 Mar 2006
Posts: 45
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| Posted: Thu Dec 10, 2009 12:32 am |
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| PCM programmer wrote: | You want to test your theory of using another interrupt pin to detect a
level change event (i.e., to detect an edge). You have posted way too
much code for this test. You don't need all those interrupt routines. You
don't need all the x++ stuff. You don't need the #byte statements.
You don't need #fast io mode. The test could be done in 10 lines,
probably. That's why you're not getting an answer. Strip it down to
essentials. |
I know your trying to help, and I appreciate it. But some of what you said is incorrect.
Or so it seems to me.
>>The test could be done in 10 lines, probably.
If that is true, given details added below, perhaps you would show me?
Meanwhile, below is my code, stripped down.
I need to select which pin(s) are used as interrupt-on-change according to 9.11 PORTB Interrupt-on-Change,
but according to 10.3.2 INTERRUPT-ON-CHANGE only RB<7:4> configured as input can cause interrupt.
I may need to make RB4 a non-output to disable its PWM and I have no idea about RB7 & 6.
So I added the definition of IOCB and set the bit I wanted as input.
When I first started testing, I missed that CCP2 could be forcing RB3 to be low so I tried setting all the pull-ups by adding #byte LDR_WPUB = 0xF7C.
I used fast IO because I eventually wanted to read portB as a byte, but using standard IO the input_b() statement would change the states of the PWM outputs.
I want the x++ as a simple location of where to add breakpoints.
Since I want interrupts, I left the interrupt routines as stubs for now.
| Code: | //Compiler version 4.099
#include <18F24K20.h>
#device ICD=TRUE
#FUSES INTRC_IO //Internal RC Osc, no CLKOUT
#FUSES MCLR //Master Clear pin enabled
#FUSES CCP2B3 // enable the CCP2 pin to be used as a button input
#FUSES NOPBADEN //PORTB pins are configured as digital
#use delay(clock=1000000)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,stream=CONSOLE)
#BYTE IOCB = 0xf7d // interrupt on change bit control
int8 current, x, key, current2;
#int_RB
void RB_isr(void)
{
}
#int_CCP2
void CCP2_isr(void)
{
}
#int_EXT
void EXT_isr(void)
{
}
void main()
{
IOCB = 0x20; // enable interrupt on change for RB5
x=0;
disable_interrupts(GLOBAL);
clear_interrupt(INT_RB);
enable_interrupts(INT_RB);
// clear_interrupt(INT_EXT);
// enable_interrupts(INT_EXT);
clear_interrupt(INT_CCP2);
enable_interrupts(INT_CCP2);
/////////////////////////////////////////////////////////////////////
setup_ccp2(CCP_CAPTURE_FE); // don't care about value, just want the clock edge
// for use as button push detection
/////////////////////////////////////////////////////////////////////
set_tris_b(0b00101000); // RB5 & RB3 set these as inputs
port_b_pullups(TRUE); // bits 0, 3, 5 ; intr, up, dn
while(1)
{
fprintf(CONSOLE, "\r\nPress any key.");
key=fgetc(CONSOLE);
fputc(key,CONSOLE); // echo the pressed key
current=input(PIN_B3);
current2=input(PIN_B5);
fprintf(CONSOLE, "\r\n");
fprintf(CONSOLE, "%u",current);
fprintf(CONSOLE, " ");
fprintf(CONSOLE, "%u",current2);
}
} |
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