~toykeeper/flashlight-firmware/fsm

// fsm-pcint.c: PCINT (Pin Change Interrupt) functions for SpaghettiMonster.

// Copyright (C) 2017-2023 Selene ToyKeeper

// SPDX-License-Identifier: GPL-3.0-or-later

#pragma once

#include <avr/interrupt.h>

#include <util/delay_basic.h>

uint8_t button_is_pressed() {

    uint8_t value = ((SWITCH_PORT & (1<<SWITCH_PIN)) == 0);

    button_last_state = value;

    return value;

}

inline void PCINT_on() {

    #if (ATTINY == 25) || (ATTINY == 45) || (ATTINY == 85)

        // enable pin change interrupt

        GIMSK |= (1 << PCIE);

        // only pay attention to the e-switch pin

        #if 0  // this is redundant; was already done in main()

        PCMSK = (1 << SWITCH_PCINT);

        #endif

        // set bits 1:0 to 0b01 (interrupt on rising *and* falling edge) (default)

        // MCUCR &= 0b11111101;  MCUCR |= 0b00000001;

    #elif (ATTINY == 1634)

        // enable pin change interrupt

        #ifdef SWITCH2_PCIE

        GIMSK |= ((1 << SWITCH_PCIE) | (1 << SWITCH2_PCIE));

        #else

        GIMSK |= (1 << SWITCH_PCIE);

        #endif

    #elif defined(AVRXMEGA3)  // ATTINY816, 817, etc)

        SWITCH_ISC_REG |= PORT_ISC_BOTHEDGES_gc;

    #else

        #error Unrecognized MCU type

    #endif

}

inline void PCINT_off() {

    #if (ATTINY == 25) || (ATTINY == 45) || (ATTINY == 85)

        // disable all pin-change interrupts

        GIMSK &= ~(1 << PCIE);

    #elif (ATTINY == 1634)

        // disable all pin-change interrupts

        GIMSK &= ~(1 << SWITCH_PCIE);

    #elif defined(AVRXMEGA3)  // ATTINY816, 817, etc)

        SWITCH_ISC_REG &= ~(PORT_ISC_gm);

    #else

        #error Unrecognized MCU type

    #endif

}

//void button_change_interrupt() {

#if (ATTINY == 25) || (ATTINY == 45) || (ATTINY == 85) || (ATTINY == 1634)

    #ifdef PCINT_vect

    ISR(PCINT_vect) {

    #else

    ISR(PCINT0_vect) {

    #endif

#elif defined(AVRXMEGA3)  // ATTINY816, 817, etc)

    ISR(SWITCH_VECT) {

        // Write a '1' to clear the interrupt flag

        SWITCH_INTFLG |= (1 << SWITCH_PIN);

#else

    #error Unrecognized MCU type

#endif

    irq_pcint = 1;  // let deferred code know an interrupt happened

    //DEBUG_FLASH;

    // as it turns out, it's more reliable to detect pin changes from WDT

    // because PCINT itself tends to double-tap when connected to a

    // noisy / bouncy switch (so the content of this function has been

    // moved to a separate function, called from WDT only)

    // PCINT_inner(button_is_pressed());

}

// should only be called from PCINT and/or WDT

// (is a separate function to reduce code duplication)

void PCINT_inner(uint8_t pressed) {

    button_last_state = pressed;

    // register the change, and send event to the current state callback

    if (pressed) {  // user pressed button

        push_event(B_PRESS);

        emit_current_event(0);

    } else {  // user released button

        // how long was the button held?

        push_event(B_RELEASE);

        emit_current_event(ticks_since_last_event);

    }

    ticks_since_last_event = 0;

}