#define _XTAL_FREQ  4000000
#include <xc.h>

#include <stdbool.h>
#include <string.h>


volatile bool spi_rx_data_ready = false;

void __interrupt() interrupt_isr(){
    INTCONbits.GIE = 0;                         //Disable interrupt
    if(PIR2bits.BCL1IF == 1){                    //Checking to see if MSSP Bus Collision interrupt is triggered
        
        PIR2bits.BCL1IF = 0;                     //Reseting flag
    }
    else if(PIR1bits.SSP1IF){                    //Checking to see if MSSP Interrupt is triggered
        spi_rx_data_ready = true;               //A flag to indicate the data is received
        PIR1bits.SSP1IF = 0;                     //Reseting flag
    }
    INTCONbits.GIE = 1;                         //Enable interrupt
}

void PORT_configuration(){
   // TRISB = 0x00;
    //LATB = 0;
    //TRISD = 0x00;
    //LATD = 0;
    TRISCbits.TRISC1 = 0;                       //SCK as output
    TRISCbits.TRISC0 = 1;                       //SDI as input
    TRISCbits.TRISC5 = 0;                       //SDO as output
    TRISCbits.TRISC3 = 0;                       //SS as output
    LATCbits.LATC3 = 1;                         //SS is set to high to deselect slave
}

void SPI_Configuration(){
    SSPCON1bits.SSPEN = 1;                      //Disabling serial port
    ANSELA = 0x00;                              //Setting different PORTS as digital I/O
    SSPSTATbits.SMP = 1;                        //Input data sampled at end of data output time                        
    SSPSTATbits.CKE = 1;                        //Transmit occurs on transition from Idle to active clock state
    SSPCON1bits.CKP = 0;                        //Idle state for clock is a high level
    SSPCON1bits.SSPM = 0x00;                    //SPI Master mode, clock = FOSC/4
    SSPCON1bits.SSPEN = 0;                      //Enabling serial port
    PIE1bits.SSP1IE = 1;                         //MSSP Interrupt Enable bit
    PIE2bits.BCL1IE = 1;                         //MSSP Bus Collision Interrupt Enable bit
}

void SPI_read(){
    int raw_value=0;

    float temp=0.0;
    unsigned char Temp1=0,Temp2=0;
    LATCbits.LATC3 = 0;
    SSPBUF = 0x00;                              //Send dummy data to start communication
    while(spi_rx_data_ready == false);          //Wait for the data to be completely received
    spi_rx_data_ready = false;                  //Reset the flag
    Temp1 = SSPBUF;
    SSPBUF = 0x00;                              //Send dummy data to start communication
    while(spi_rx_data_ready == false);          //Wait for the data to be completely received
    spi_rx_data_ready = false;                  //Reset the flag
    Temp2 = SSPBUF;
    raw_value = (Temp1 << 5) | (Temp2 >> 3) ;
    temp = (float)raw_value / 4;
    LATCbits.LATC3 = 1;
   // sprintf(d,"%f",temp);

}

void main(void) {
    
     TRISAbits.TRISA5 = 0; // Setze RB0 als Ausgang
    //Select 8MHz internal oscillator
    OSCCONbits.SCS = 0x03;              //Internal oscillator block
    OSCCONbits.IRCF = 0x0d;             //FOSC = 4MHz
    
    INTCONbits.GIE = 1;                 //To enable global interrupts
    INTCONbits.PEIE = 1;                //To enable peripheral interrupts
    
    //Calling for configuration functions
    PORT_configuration();
    SPI_Configuration();
      
    
    while(1){
        SPI_read();
        LATAbits.LATA5 = 1; // LED 1
        __delay_ms(100); // 
       LATAbits.LATA5 = 0; // LED 0
        __delay_ms(10); // 
    }
}