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#include <xc.h>

#include "defines.h"

#include "base_CPS.h"

static CPS_DATA *cps_data_p;

void CPS_Init(CPS_DATA* data) {

    cps_data_p = data;

    for (char i = 0; i < 4; i++) {

        cps_data_p->btn_pressed[i] = 0;

        cps_data_p->btn_last_value[i] = 0;

        cps_data_p->btn_avg_value[i] = 0;

        cps_data_p->btn_pct_value[i] = 0;

    }

    /* Initialize port direction */

    CPS_0_TRIS = 1;

    CPS_1_TRIS = 1;

    /* Initialize FVR for the upper threshold (Ref+) */

    FVRCONbits.CDAFVR = 0b01; // Gain of 1x (1.024V)

    FVRCONbits.FVREN = 1; // Enable FVR module

    /* Initialize DAC for the lower threshold (Ref-) to Vss */

    DACCON0bits.DACEN = 0; // Disable DAC

    DACCON0bits.DACLPS = 0; // Negative reference source selected

    DACCON0bits.DACOE = 0; // Output not routed to DACOUT pin

    DACCON0bits.DACPSS = 0b00; // Vss used as positive source

//    DACCON0bits.DACNSS = 0; // Vss used as negative source

    // Output voltage formula:

    //  V_out = ((V_source+ - V_source-) * (DACR / 32)) + V_source-

    DACCON1bits.DACR = 0b00000; // Voltage output set to 0v

//    /* Initialize DAC for the lower threshold (Ref-) to variable setting */

//    DACCON0bits.DACEN = 1; // Enable DAC

//    DACCON0bits.DACLPS = 1; // Positive reference source selected

//    DACCON0bits.DACOE = 0; // Output not routed to DACOUT pin

//    DACCON0bits.DACPSS = 0b10; // FVR buffer2 used as positive source

////    DACCON0bits.DACNSS = 0; // Vss used as negative source

//    // Output voltage formula:

//    //  V_out = ((V_source+ - V_source-) * (DACR / 32)) + V_source-

//    DACCON1bits.DACR = 0b10000; // Voltage output set to 0.512v

    /* Initialize Timer 0 */

    OPTION_REGbits.TMR0CS = 0; // Clock source is FOSC/4

    OPTION_REGbits.PSA = 0; // Prescaler enabled

    OPTION_REGbits.PS = 0b111; // Prescaler of 1:256

    /* Initialize Timer 1 */

    T1CONbits.TMR1CS = 0b11; // Clock source is Capacitive Sensing Oscillator

    T1CONbits.T1CKPS = 0b00; // 1:1 Prescale value

    T1GCONbits.TMR1GE = 1; // Counting is controlled by the gate function

    T1GCONbits.T1GPOL = 1; // Gate is active high

    T1GCONbits.T1GTM = 1; // Gate toggle mode is enabled

    T1GCONbits.T1GSPM = 0; // Gate single-pulse mode is disabled

    T1GCONbits.T1GSS = 0b01; // Gate source is Timer 0 overflow

    T1CONbits.TMR1ON = 1; // Enables timer 1

    /* Initialize CPS Module */

    CPSCON0bits.CPSRM = 1; // DAC and FVR used for Vref- and Vref+

    CPSCON0bits.CPSRNG = 0b11; // Osc in high range (100uA)

    CPSCON0bits.T0XCS = 0; // Timer 0 clock runs at FOSC/4

    CPSCON1bits.CPSCH = 0b00; // Channel 0 (CPS0)

    cps_data_p->channel = 0;

    CPSCON0bits.CPSON = 1; // CPS module is enabled

    /* Initialize timer interrupts and clear timers */

    INTCONbits.TMR0IE = 1; // Timer 0 interrupt enabled

    PIE1bits.TMR1IE = 0; // Timer 1 interrupt disabled

    CPS_Reset();

}

void CPS_Timer_0_Interrupt_Handler() {

    unsigned int value = TMR1;

    long percent;

    if (value < 10) {

        return;

    }

    // Calculate percentage change

    percent = (long)cps_data_p->btn_avg_value[cps_data_p->channel]-(long)value;

    if (percent < 0)

        percent = 0;

    else {

        percent *= 100;

        percent /= cps_data_p->btn_avg_value[cps_data_p->channel];

    }

    cps_data_p->btn_last_value[cps_data_p->channel] = value;

    cps_data_p->btn_pct_value[cps_data_p->channel] = percent;

    if (percent < CPS_PCT_OFF) {

        // Calculate average

        cps_data_p->btn_avg_value[cps_data_p->channel] =

            cps_data_p->btn_avg_value[cps_data_p->channel] +

            ((long)value - (long)cps_data_p->btn_avg_value[cps_data_p->channel])

            /CPS_AVG_COUNT;

        // Set flag to indicate that button is not pressed

        cps_data_p->btn_pressed[cps_data_p->channel] = 0;

    } else if (percent > CPS_PCT_ON) {

        // Set flag to indicate that button was pressed

        cps_data_p->btn_pressed[cps_data_p->channel] = 1;

    }

    cps_data_p->channel = cps_data_p->channel + 1;

    if (cps_data_p->channel == CPS_NUM_CHANNELS)

        cps_data_p->channel = 0;

    CPSCON1bits.CPSCH = cps_data_p->channel;

    CPS_Reset();

}

void CPS_Reset() {

    TMR1 = 0;

    TMR0 = 0;

}

void CPS_Enable() {

    INTCONbits.TMR0IE = 1; // Timer 0 interrupt enabled

    T1CONbits.TMR1ON = 1;

    CPSCON0bits.CPSON = 1;

    CPS_Reset();

}

void CPS_Disable() {

    INTCONbits.TMR0IE = 0;

    CPSCON0bits.CPSON = 0;

    T1CONbits.TMR1ON = 0;

}