Objective Development Forums

Re: PCINT instead of INT0?

2010-07-12T11:36:07+02:00

Yes, INT0_vect is already there in the repository, it will be published with the next release.

Statistics: Posted by christian — Mon Jul 12, 2010 11:36 am

Re: PCINT instead of INT0?

2010-07-12T10:27:26+02:00

Hi Christian,

thanks for the hint! I think we are getting closer. I did a simple test.
I added the lines

Code:

#ifdef SIG_PIN_CHANGE
crash
#endif

to usbconfig.h and tried to compile. No error messages => SIG_PIN_CHANGE is undefined!
Replacing SIG_PIN_CHANGE by SIG_INTERRUPT1 will cause a compiler crash as expected if SIG_INTERRUPT1 is defined.

Where should SIG_PIN_CHANGE get defined and what should be its value?...

P.S.

... Ok, found and fixed it, hurray, it is working now!
Vectors are defined in , see avrgcc manual.

SIG_PIN_CHANGE should read SIG_PIN_CHANGE0 (old) or better PCINT0_vect (new).
Also, I think in the usbconfig.h template SIG_INTERRUPT0 should be replaced by INT0_vect, as the former old name is not supported for all MCUs, e.g. not for Mega328P.

Thanks for pointing me in the right direction,
Tom

Statistics: Posted by iphi — Mon Jul 12, 2010 10:27 am

Re: PCINT instead of INT0?

2010-07-12T10:01:14+02:00

Have you verified the interrupt vector? If SIG_PIN_CHANGE is not defined, the interrupt handler will never be called and there's no compiler/linker warning or error. Please check main.elf with

avr-objdump -d main.elf

Then check the verctor address for pin change and see whether it contains the jump to your handler.

Statistics: Posted by christian — Mon Jul 12, 2010 10:01 am

Re: PCINT instead of INT0?

2010-07-11T20:34:30+02:00

Hi Christian,

I have read the data sheet and written some test code. This is what it takes to enable a PCINT0 on a Mega88:

Code:

sei();
PCICR=PCICR | (1 << PCIE0);
PCMSK0=PCMSK0 | (1 << PCINT0);

as compaared to enabling an INT0:

Code:

sei();
EICRA=EICRA | ((1 << ISC00) | (1 << ISC01));   
EIMSK=EIMSK | (1 << INT0);

Still, V-USB doesn't run on PCINT0 on my Mega88 while my interrupt test code lets the interrupt happily trigger.
V-USB and INT0 or INT1 works fine.

Here are my V-USB settings again:

Code:

#define USB_INTR_CFG            PCICR         
#define USB_INTR_CFG_SET        (1 << PCIE0)     
//#define USB_INTR_CFG_CLR        0 
#define USB_INTR_ENABLE         PCMSK0        
#define USB_INTR_ENABLE_BIT     PCINT0        
#define USB_INTR_PENDING        PCIFR         
#define USB_INTR_PENDING_BIT    PCIF0         
#define USB_INTR_VECTOR         SIG_PIN_CHANGE

Please help.

Thanks, Tom

Statistics: Posted by iphi — Sun Jul 11, 2010 8:34 pm

Re: PCINT instead of INT0?

2010-07-09T17:35:48+02:00

Yes, this means that the handler is never called. It seems that either the vector address is not correct (you can check this with a disassembler listing of the linked code) or the interrupt is not enabled. Don't know which steps are required to enable a PCINT, I would have to read the data sheet...

Statistics: Posted by christian — Fri Jul 09, 2010 5:35 pm

Re: PCINT instead of INT0?

2010-07-08T21:11:24+02:00

Hi Christian,

I have used the flooowing hook to check if the interrupt handler is called:

Code:

#define USB_RX_USER_HOOK(data, len)  PORTC=~PORTC;

Is this the correct way to check?

I have an LED connected to PORTC. With INT1 I see it toggeling a couple of times when I plug in the device.
Using PCINT0 I see no action whatsoever. Does this mean the interrupt handler is never called?

Where could I look to solve the problem?

Thanks, Tom

Statistics: Posted by iphi — Thu Jul 08, 2010 9:11 pm

Re: PCINT instead of INT0?

2010-07-08T18:53:06+02:00

No, the driver works with all three, rising edge, falling edge and change triggered interrupt. You should verify whether the interrupt handler is actually called...

Statistics: Posted by christian — Thu Jul 08, 2010 6:53 pm

Re: PCINT instead of INT0?

2010-07-08T18:24:51+02:00

it looks like if you use external interrupts (as in INT0, INT1, etc), the interrupt is generated on a rising edge signal. Pin change interrupts occur regardless of rising or falling edge. This may be one problem.

Statistics: Posted by frank26080115 — Thu Jul 08, 2010 6:24 pm

Re: PCINT instead of INT0?

2010-07-08T12:24:14+02:00

Hi Christian,

thank you very much for your hint. I could get it working on INT1 instead of INT0 on a Mega88.
I am still having trouble using the PCINT0 instead.

Here are my settings for PCINT0, which compile fine but refuse to work.
Can somebody point me to my error, please?

Code:

                                     //commented values for INT1 work fine
#define USB_INTR_CFG            PCICR         //EICRA
#define USB_INTR_CFG_SET        (1 << PCIE0)     //((1 << ISC10) | (1 << ISC11))    //00,01 for INT0
//#define USB_INTR_CFG_CLR        0 
#define USB_INTR_ENABLE         PCMSK0        //EIMSK 
#define USB_INTR_ENABLE_BIT     PCINT0        //INT1
#define USB_INTR_PENDING        PCIFR         //EIFR 
#define USB_INTR_PENDING_BIT    PCIF0         //INTF1 
#define USB_INTR_VECTOR         SIG_PIN_CHANGE  //SIG_INTERRUPT1

Statistics: Posted by iphi — Thu Jul 08, 2010 12:24 pm

Re: PCINT instead of INT0?

2010-07-05T18:02:58+02:00

See viewtopic.php?f=8&t=1067

Statistics: Posted by christian — Mon Jul 05, 2010 6:02 pm