Interrupts

/*                          Interrupts (source code)                          */  
/*                            MCU: PIC24FJ256GA702                            */
/*                              Author: Michael                               */

/**************************** Configuration Bits ******************************/

// FSEC
#pragma config BWRP = OFF                                                       // Boot Segment Write-Protect bit (Boot Segment may be written)
#pragma config BSS = DISABLED                                                   // Boot Segment Code-Protect Level bits (No Protection (other than BWRP))
#pragma config BSEN = OFF                                                       // Boot Segment Control bit (No Boot Segment)
#pragma config GWRP = OFF                                                       // General Segment Write-Protect bit (General Segment may be written)
#pragma config GSS = DISABLED                                                   // General Segment Code-Protect Level bits (No Protection (other than GWRP))
#pragma config CWRP = OFF                                                       // Configuration Segment Write-Protect bit (Configuration Segment may be written)
#pragma config CSS = DISABLED                                                   // Configuration Segment Code-Protect Level bits (No Protection (other than CWRP))
#pragma config AIVTDIS = OFF                                                    // Alternate Interrupt Vector Table bit (Disabled AIVT)

// FBSLIM
#pragma config BSLIM = 0x1FFF                                                   // Boot Segment Flash Page Address Limit bits (Enter Hexadecimal value)

// FOSCSEL
#pragma config FNOSC = PRIPLL                                                   // Oscillator Source Selection (Primary Oscillator with PLL module (XT + PLL, HS + PLL, EC + PLL))
#pragma config PLLMODE = PLL96DIV4                                              // PLL Mode Selection (96 MHz PLL. Oscillator input is divided by 4 (16 MHz input))
#pragma config IESO = OFF                                                       // Two-speed Oscillator Start-up Enable bit (Start up with user-selected oscillator source)

// FOSC
#pragma config POSCMD = HS                                                      // Primary Oscillator Mode Select bits (HS Crystal Oscillator Mode)
#pragma config OSCIOFCN = ON                                                    // OSC2 Pin Function bit (OSC2 is general purpose digital I/O pin)
#pragma config SOSCSEL = OFF                                                    // SOSC Power Selection Configuration bits (Digital (SCLKI) mode)
#pragma config PLLSS = PLL_PRI                                                  // PLL Secondary Selection Configuration bit (PLL is fed by the Primary oscillator)
#pragma config IOL1WAY = OFF                                                    // Peripheral pin select configuration bit (Allow multiple reconfigurations)
#pragma config FCKSM = CSDCMD                                                   // Clock Switching Mode bits (Both Clock switching and Fail-safe Clock Monitor are disabled)

// FWDT
#pragma config WDTPS = PS1                                                      // Watchdog Timer Postscaler bits (1:1)
#pragma config FWPSA = PR32                                                     // Watchdog Timer Prescaler bit (1:32)
#pragma config FWDTEN = OFF                                                     // Watchdog Timer Enable bits (WDT and SWDTEN disabled)
#pragma config WINDIS = OFF                                                     // Watchdog Timer Window Enable bit (Watchdog Timer in Non-Window mode)
#pragma config WDTWIN = WIN50                                                   // Watchdog Timer Window Select bits (WDT Window is 50% of WDT period)
#pragma config WDTCMX = WDTCLK                                                  // WDT MUX Source Select bits (WDT clock source is determined by the WDTCLK Configuration bits)
#pragma config WDTCLK = SYSCLK                                                  // WDT Clock Source Select bits (WDT uses system clock when active, LPRC while in Sleep mode)

// FPOR
#pragma config BOREN = OFF                                                      // Brown Out Enable bit (Brown Out Disabled)
#pragma config LPCFG = OFF                                                      // Low power regulator control (No Retention Sleep)
#pragma config DNVPEN = DISABLE                                                 // Downside Voltage Protection Enable bit (Downside protection disabled when BOR is inactive)

// FICD
#pragma config ICS = PGD1                                                       // ICD Communication Channel Select bits (Communicate on PGEC1 and PGED1)
#pragma config JTAGEN = OFF                                                     // JTAG Enable bit (JTAG is disabled)

// FDEVOPT1
#pragma config ALTCMPI = DISABLE                                                // Alternate Comparator Input Enable bit (C1INC, C2INC, and C3INC are on their standard pin locations)
#pragma config TMPRPIN = OFF                                                    // Tamper Pin Enable bit (TMPRN pin function is disabled)
#pragma config SOSCHP = ON                                                      // SOSC High Power Enable bit (valid only when SOSCSEL = 1 (Enable SOSC high power mode (default))
#pragma config ALTI2C1 = ALTI2CEN                                               // Alternate I2C pin Location (SDA1 and SCL1 on RB9 and RB8)

/************************* Configuration Bits (end) ***************************/

#define FCY 16000000                                                            // FCY = FOSC / 2 (FCY: Instruction clock cycle) (FOSC: System clock cycle)
#define LED_Green_1 LATBbits.LATB15                                             // LED_Green_1 associated with MCU Pin #26
#define LED_Green_2 LATBbits.LATB14                                             // LED_Green_2 associated with MCU Pin #25
#define LED_Green_3 LATBbits.LATB13                                             // LED_Green_3 associated with MCU Pin #24
#define LED_Green_4 LATBbits.LATB12                                             // LED_Green_4 associated with MCU Pin #23
#define LED_Red_5 LATBbits.LATB11                                               // LED_Red_5 associated with MCU Pin #22

#include <libpic30.h>                                                           // Delay functions
#include <xc.h>                                                                 // MCU pin mapping

void __attribute__((interrupt, no_auto_psv)) _INT0Interrupt(void)               // ISR (External Interrupt 0) (PIC24FJ256GA702 datasheet p.87 Table 8-2)
{
    LED_Red_5 = 1;                                                              // LED_Red_5 ON
    __delay_ms(500);                                                             
    LED_Red_5 = 0;                                                              // LED_Red_5 OFF
    IFS0bits.INT0IF = 0;                                                        // Clear External Interrupt 0 Flag
}

int main(void)                           
{
    
    // Set pin direction 
    TRISBbits.TRISB15 = 0;                                                      // MCU Pin #26 output (LED_Green_1)
    TRISBbits.TRISB14 = 0;                                                      // MCU Pin #25 output (LED_Green_2)
    TRISBbits.TRISB13 = 0;                                                      // MCU Pin #24 output (LED_Green_3)
    TRISBbits.TRISB12 = 0;                                                      // MCU Pin #23 output (LED_Green_4)
    TRISBbits.TRISB11 = 0;                                                      // MCU Pin #22 output (LED_Red_5)
    TRISBbits.TRISB7 = 1;                                                       // MCU Pin #16 input (Switch_1)

    /************************* configure MCU modules **************************/
    
    // Analog Ports
    ANSA = 0;                                                                   // Disable A (PIC24FJ256GA702 datasheet p.126 Table 11-1)
    ANSB = 0;
    
    // Comparators
    CM1CONbits.CEN = 0;                                                         // Disable #1 (PIC24FJ256GA702 datasheet p.310 Register 25-1)
    CM2CONbits.CEN = 0;                                                         
    CM3CONbits.CEN = 0;                                                                                                                          
    
    // ADC
    AD1CON1bits.ADON = 0;                                                       // Disable module (PIC24FJ256GA702 datasheet p.291 Register 24-1)
    
    // Interrupt Controller (External Interrupt 0)                                                                                                             
    INTCON2bits.INT0EP = 1;                                                     // Interrupt on negative edge
    IFS0bits.INT0IF = 0;                                                        // Clear INT0 Interrupt Flag
    IEC0bits.INT0IE = 1;                                                        // Enable INT0 Interrupt

    /********************** configure MCU modules (end) ***********************/
    
    while (1)
    {   

       LED_Green_1 = 1;                                                         // LED_Green_1 ON
       __delay_ms(500);
       LED_Green_1 = 0;                                                         // LED_Green_1 OFF
       LED_Green_2 = 1;
       __delay_ms(500);
       LED_Green_2 = 0;
       LED_Green_3 = 1;
       __delay_ms(500);
       LED_Green_3 = 0;
       LED_Green_4 = 1;
       __delay_ms(500);
       LED_Green_4 = 0;
                      
    } 
    
    return 0;
    
}