What is the best way to control PCINT0.3 of ATtiny85

[sfiga69]

excuse me, but I have little experience with the AVR 8bit.
I have to control the PCINT0.3 interrupt of a attiny85.
The simulation in Proteus with the connection 1, it works correctly, but in practice no. The pin PCINT0.3 always remains at a low level (0.4 - 0.6V).
if I configure the pin as an input, the levels are correct (0 - 4.4V) but the interrupt does not trigger.
What is the correct method to interrupt drive? (1 or 2)

thanks

[pickit2]

show us your code... you have to be careful using Proteus, they expect you to have set the fuses correctly.
Example enter code for a pic16f84 change device and the code still runs.

I suspect your fuse setting are wrong. if set correct it should be high. you enable pull up resistor, or have a resistor in your circuit.

[kreutz]

You should not only configure it as input but also enable interrupts and have the proper interrupt routine written in order for it to work. Check the code.

[TucoRamirez]

yup, gotta disable all the other alternative functions on that pin  (Analog in, comparators, i.e.)  and as i can see, check the fuses to activate the internal osc and detach from the XTAL pin circuitry

[mars01]

The schematic in figure 1 is OK.

On how to configure things, have a look on what this guy done here:
http://www.avrfreaks.net/forum/pin-change-interrupts-attiny-beginners

For PCINT3 test I would do a code like this (make sure that you have debounce on the LED of the opto if the signal is bouncing):

Code:

// ADD a LED (with resistor) on pin5 of the uC and use the pin change interrupt function on pin 2 of the uC

volatile unsigned char flag = 0;

ISR(PCINT3_vect)	                    // interrupt service routine
{			                    // called when PCINT3 changes state     
        flag++;
        return;
}

void SystemInit(void)
{
	PCMSK |= (1<<PCINT3);     // pin change mask: listen to PORTB bit 3
	GIMSK |= (1<<PCIE);       // enable PCINT interrupt 
	sei();			  // enable all interrupts
}

void main(void) {
        ADCSRA = 0;                    // ADC is disabled (because bit7 is 0)
        ACSR = 0;                      // comparator OFF (because bit7 is 0)
   	DDRB = 0b00000001;  	       // PORTB bit 0 is OUTPUT the rest are INPUT's
        PORTB &= ~(1 << 3);  	       // PORTB bit 3 internal pull-up resistor disabled 
	SystemInit();

        while(1) {
            // the LED on PORTB bit 0 will change state only when the pin change from HIGH to LOW and then HIGH again - schematic in FIG 1 was used 
            if (flag >= 2) {
                 cli();              
                 flag = 0;
                 PORTB = (PORTB ^ 0x01);     // toggle red led on PORTB bit 0
                 sei();
            }
        }
} 

[sfiga69]

I have attached a test Proteus project with the source bascomAvr to check the interrupt operation.
I'm trying on a digispark with D + and D- USB's cut, so as not to have influences on PB3 (usb only for power).
Proteus you can see that in the two cases all operating normally.
practically the P2 and P1 button have no effect.
I think I properly set the bits required to operate according to the ATtiny85 datasheet:
GIMSK, Bit 5 - PCIE: Pin Change Interrupt Enable
PCMSK, BIT 3 - PCINT3 Pin Change Mask Register

from datasheet:
9.2 External Interrupts
......  Observe that, if enabled, the interrupts will trigger even if the INT0 or PCInt [5: 0] pins are configured as outputs. This feature Provides a way of
generating a software interrupt. Pin change interrupts PCI will trigger if any enabled PCInt [5: 0] pin toggles. .....
 
If I put:
Portb.1 config = Output
Proteus acts as the digispark:
P1 = no effect
P2 = triggered the interrupt

Thanks for your help

[kreutz]

Can't help, I don't use Proteus. If you post the code I might be able to take a look at it.

[sfiga69]

schematics and code

Code:

'       LB    FBL    FBH    FBE
$prog &HFF , &HF1 , &HDF , &HFF

$regfile = "attiny85.dat"
$crystal = 16000000
$hwstack = 40
$swstack = 40
$framesize = 40

On Pcint0 Isr_int0											' interrupt service routine
Set Gimsk.5 												' enable PCIE = PCINT0 enable interrupt
Set Pcmsk.3                                                 ' enable PCINT3

Config Portb.1 = Output
'config portb.3 = output

Start1:

Enable Interrupts
Do

Loop
End

Return

'***************************************************************************
'* interrupt routine INT0
'***************************************************************************

Isr_int0:

Toggle Portb.1

Return

[mars01]

Hi,

I've made a fast program in mikroC for AVR.
The code works as it is supposed to and it is like this:

Code:

volatile unsigned char flag = 0;

void PCINT3_ISR() iv IVT_ADDR_PCINT0 ics ICS_AUTO {
     flag++;
}

void init_sys(){
     ADEN_bit = 0;      // disable ADC
     ACD_bit = 0;       // disable Analog Comparator
     DDRB = 0b00000010; // set PORTB bit 1 as OUTPUT, the rest are INPUT's
     PORTB3_bit = 0;    // disable internal pull-up on bit 3 of the PORTB
     
     PCINT3_bit = 1;    // enable interrupt on PCINT3
     PCIE_bit = 1;      // enable pin change interrupts
     SREG_I_bit = 1;    // enable interrupts
}

void main() {
     init_sys();
     for(;;) {
        // the LED on PORTB bit 0 will change state only when the pin change from HIGH to LOW and then HIGH again - schematic in FIG 1 was used
        if (flag >= 2) {
           SREG_I_bit = 0;             // disable interrupts
           flag = 0;
           PORTB = (PORTB ^ 0x02);     // toggle led on PORTB bit 1
           SREG_I_bit = 1;             // enable interrupts
        }
     }
}

I've attached an archive that contain the mikroC for AVR project and Proteus 8.4 simulation. I hope that this will solve your problem.
Unfortunately I don't code in Bascom but if you look at the program structure you might easily port it.

[sfiga69]

thanks mars01
 I try and tell you if it works

[kreutz]

Sfiga69, I can't see where you declare the interrupt type (rising edge, falling edge, etc) for int0 on the code above, and where you enable int0 specifically after enabling all interrups.  At least in my older versions of BascomAVR you need to do that.

For example (on this code for an Atmega16):

Config Portd = &B11110011                                   ' PORTD AS output 0,1,4.5.6.7 and
'                                                            input portd2(Int0), portd3 (Int1)

'======================================                      '----------------
Config Int0 = Rising                                        'PORTD.2  ZERO CROSING INTERRUPT PULSES
'                                                             'ACTIVE HIGH USE THE RISING EDGE

 
Enable interrupts
Enable Int0  

[mars01]

Hi @kreutz,
The OP is not working with the external interrupt INT0 but with pin change interrupt PCINT0:5 specifically with source 3 for the pin change interrupt, PCINT3.

@sfiga69, if you test the code that I posted and you use a mechanical button, make sure that you use a low pass filter on the interrupt pin to counter the bouncing of the contacts otherwise you might not see what you expect.

[kreutz]

From the BascomAVR help file:

 "There are multiple interrupt sources and it depends on the used chip which are available.
 
To allow the use of interrupts you must set the global interrupt switch with an ENABLE INTERRUPTS statement. This only allows that interrupts can be used. You must also set the individual interrupt switches on!
 
ENABLE TIMER0 for example allows the TIMER0 interrupt to occur.
 
With the DISABLE statement you turn off the switches..."

My partial code above is just an example.

Posted on: July 03, 2016, 05:40:19 17:40 - Automerged
mars01;

I will look into my old programs for a reference example on pin change interrupt  but, basically, they should be similar.

[kreutz]

Maybe the following links with examples will help solving your problem: http://electronics598.rssing.com/browser.php?indx=8435866&item=4222   https://sites.google.com/site/qeewiki/books/avr-guide/external-interrupts-on-the-atmega328

[sfiga69]

thanks at all, solved!!!
In basic the problem is a configuration of pin PB3.
@mars01, your code work.. I translated into basic your code in C and now works
in particular:
In C
DDRB = 0b00000010;      
PORTB3_bit = 0;  
In basic
Ddrb.3 = 0                                                  ' PB3 = input for PCINT3
Config Portb.3 = 0                                         ' portb.3 disable pullup
then moving before the interrupt configuration.
in this way, it works correctly in 2 configurations

Code:

$prog &HFF , &HF1 , &HDF , &HFF


$regfile = "attiny85.dat"
$crystal = 16000000
$hwstack = 40
$swstack = 40
$framesize = 40

Ddrb.1 = 1                                                  ' PB1 = output for led
Ddrb.3 = 0                                                  ' PB3 = input for PCINT3
Config Portb.3 = 0                                          ' portb.3 disable pullup

On Pcint0 Isr_int0
Set Gimsk.5
Set Pcmsk.3

Start1:

Enable Interrupts

Do


Loop
End


Return

'***************************************************************************
'* interrupt routine INT0
'***************************************************************************

Isr_int0:

Toggle Portb.1

Return

for debouncing, no problem in fact P1 or P2 is a Reflective photosensor.
this is a part of tachometer for spindler of my CNC.
when I finished my puzzle, it will be published in projects
thanks again to all

[sfiga69]

Sfiga69, I can't see where you declare the interrupt type (rising edge, falling edge, etc) for int0 on the code above, and where you enable int0 specifically after enabling all interrups.  At least in my older versions of BascomAVR you need to do that.

in ATtiny85 only INT0 can select rising, falling and change.
for PCINT0 (0:5) any change level triggers interrupt