Pinchangeinterrupt on PB6 / PB7

Using Arduino Microcontrollers
1

Hi all

I have a standalone 328P set to internal clock and i changed pins_arduino.h to have xtal pins (PB6 and PB7) as regular i/O ports (D20 and D21). I tested those pins with digitalRead and digitalWrite and they work fine.

Now i need to set PB6 (or PB7) to Pinchangeinterrupt, i saw this example

that uses pinchangeinterrupt on pin D2 ,but i don't know what to change to work with PB6 (or PB7).

Any help?

2

And your code is? Post something which you've tested.

PCMSK0 and PCINT0_vect is for PCINT6-7 (on PB6-7) in contrast with example from the link you've posted.

3

this is from pins_arduino.h:

const uint8_t PROGMEM digital_pin_to_port_PGM[] = {
	PD, /* 0 */
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PD,
	PB, /* 8 */
	PB,
	PB,
	PB,
	PB,
	PB,
	PC, /* 14 */
	PC,
	PC,
	PC,
	PC,
	PC,
	PB, /* add - 20  - PB6*/
    PB, /* add - 21  - PB7*/
};

const uint8_t PROGMEM digital_pin_to_bit_mask_PGM[] = {
	_BV(0), /* 0, port D */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6),
	_BV(7),
	_BV(0), /* 8, port B */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(0), /* 14, port C */
	_BV(1),
	_BV(2),
	_BV(3),
	_BV(4),
	_BV(5),
	_BV(6), /* add - 20 - PB6 */
	_BV(7), /* add - 21 - PB7 */
};

and this is my code ( where i changed i commented the original code:

#include <avr/io.h>
#include <avr/interrupt.h>


ISR(PCINT0_vect) // original: ISR(PCINT2_vect)
{
    // Read PD2 using the Port D Pin Input Register (PIND)
    if (PINC & _BV(PINC6)) // original: if (PIND & _BV(PIND2))
    {
        // PD2 is high, so button is released

        // Set PB5 low using the Port B Data Register (PORTB)
        PORTB &= ~_BV(PORTB5);
    }
    else
    {
        // PD2 is low, so button is pressed

        // Set PB5 high using the Port B Data Register (PORTB)
        PORTB |= _BV(PORTB5);
    }
}

int main(void)
{
    // Configure PD2 as an input using the Data Direction Register D (DDRD)
    
    DDRC &= ~_BV(DDD6);   // original: DDRD &= ~_BV(DDD2);

    // Enable the pull-up resistor on PD2 using the Port D Data Register (PORTD)
    
    PORTC |= _BV(PORTC6);   // original: PORTD |= _BV(PORTD2);

    // Enable pin change interrupt on the PCINT18 pin using Pin Change Mask Register 2 (PCMSK2)
    
    PCMSK0 |= _BV(PCINT6);    // original: PCMSK2 |= _BV(PCINT18);

    // Enable pin change interrupt 2 using the Pin Change Interrrupt Control Register (PCICR)
    
    PCICR |= _BV(PCIE0);    // original: PCICR |= _BV(PCIE2);

    // Configure PB5 as an output using the Port B Data Direction Register (DDRB)
    DDRB |= _BV(DDB5);

    // Enable interrupts
    sei();

    // Loop forever
    while (1)
    {
        // Nothing to do here
        // All work is done in the ISR
    }
}

Led attached to D13 is always on

4

Firstly, PB6 should be configured as input pull-up.

DDRB &= ~_BV(DDB6);
PORTB |= _BV(PORTB6);
5

Hurray, it worked.

I assumed that PB6 was PORTC, but it is PORTB.
Inside ISR i also changed PINC & _BV(PINC6) to PINB & _BV(PINB6)

Thanks budvar10, i learn alot today!

6

Great!
Heh, the names are always according port names (A, B, C...). The rule is valid for all pins, registers, bits etc. You can find more in the datasheet.