#include <driverlib.h>
#include "hal_LCD.h"

/* Defines WDT SMCLK interval for sensor measurements*/
#define WDT_meas_setting (DIV_SMCLK_512)
/* Defines WDT ACLK interval for delay between measurement cycles*/
#define WDT_delay_setting (DIV_ACLK_512)

/* Sensor settings*/
#define KEY_LVL     220                     // Defines threshold for a key press
/*Set to ~ half the max delta expected*/

/* Definitions for use with the WDT settings*/
#define DIV_ACLK_32768  (WDT_ADLY_1000)     // ACLK/32768
#define DIV_ACLK_8192   (WDT_ADLY_250)      // ACLK/8192
#define DIV_ACLK_512    (WDT_ADLY_16)       // ACLK/512
#define DIV_ACLK_64     (WDT_ADLY_1_9)      // ACLK/64
#define DIV_SMCLK_32768 (WDT_MDLY_32)       // SMCLK/32768
#define DIV_SMCLK_8192  (WDT_MDLY_8)        // SMCLK/8192
#define DIV_SMCLK_512   (WDT_MDLY_0_5)      // SMCLK/512
#define DIV_SMCLK_64    (WDT_MDLY_0_064)    // SMCLK/64

#define LED   (0x01)                        // P1.0 LED output

// Global variables for sensing
unsigned int base_cnt, meas_cnt;
int delta_cnt;
char key_pressed;
/* System Routines*/
void measure_count(void);                   // Measures each capacitive sensor
void pulse_LED(void);                       // LED gradient routine

int main( void )
{

    Init_LCD();

    unsigned int i,j;
    WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
    PM5CTL0 &= ~LOCKLPM5;

    SFRIE1 |= WDTIE;                          // enable WDT interrupt
    P1DIR |= LED;                             // P1.0 = LED
    P1OUT = 0x00;

    __bis_SR_register(GIE);                   // Enable interrupts

    measure_count();                          // Establish baseline capacitance
    base_cnt = meas_cnt;

    for(i=15; i>0; i--)                       // Repeat and avg base measurement
    {
        measure_count();
        base_cnt = (meas_cnt+base_cnt)/2;
    }

    /* Main loop starts here*/
    while (1)
    {

        j = KEY_LVL;
        key_pressed = 0;                        // Assume no keys are pressed

        measure_count();                        // Measure all sensors

        delta_cnt = base_cnt - meas_cnt;  // Calculate delta: c_change

        /* Handle baseline measurment for a base C decrease*/
        if (delta_cnt < 0)                    // If negative: result increased
        {                                     // beyond baseline, i.e. cap dec
            base_cnt = (base_cnt+meas_cnt) >> 1; // Re-average quickly
            delta_cnt = 0;                    // Zero out for pos determination
        }
        if (delta_cnt > j)                    // Determine if each key is pressed
        {                                     // per a preset threshold
            j = delta_cnt;
            key_pressed = 1;                    // key pressed
        }
        else
            key_pressed = 0;

        /* Delay to next sample */
        WDTCTL = WDT_delay_setting;             // WDT, ACLK, interval timer

        /* Handle baseline measurment for a base C increase*/
        if (!key_pressed)                       // Only adjust baseline down
        {                                       // if no keys are touched
            base_cnt = base_cnt - 1;        // Adjust baseline down, should be
        }                                       // slow to accomodate for genuine
        pulse_LED();                           // changes in sensor C

        __bis_SR_register(LPM3_bits);
    }
}                                           // End Main

/* Measure count result (capacitance) of each sensor*/
/* Routine setup for four sensors, not dependent on NUM_SEN value!*/

void measure_count(void)
{
    TA2CTL = TASSEL_3 + MC_2;                   // TACLK, cont mode
    TA2CCTL1 = CM_3 + CCIS_2 + CAP;             // Pos&Neg,GND,Cap

    /*Configure Ports for relaxation oscillator*/
    CAPSIO0CTL |= CAPTIOEN + CAPSIOPOSEL0 + CAPSIOPISEL2; //P1.1

    /*Setup Gate Timer*/
    WDTCTL = WDT_meas_setting;              // WDT, ACLK, interval timer
    TA2CTL |= TACLR;                        // Clear Timer_A TAR
    __bis_SR_register(LPM0_bits+GIE);       // Wait for WDT interrupt
    TA2CCTL1 ^= CCIS0;                      // Create SW capture of CCR1
    meas_cnt = TA2CCR1;                      // Save result
    WDTCTL = WDTPW + WDTHOLD;               // Stop watchdog timer
    CAPSIO0CTL = 0;
}

void pulse_LED(void)
{
    if(key_pressed)
    {
        P1OUT ^= LED;
    }
    else
    {
        P1OUT &= ~LED;
    }
}
/* Watchdog Timer interrupt service routine*/
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(WDT_VECTOR))) watchdog_timer (void)
#else
#error Compiler not supported!
#endif
{
    TA2CCTL1 ^= CCIS0;                        // Create SW capture of CCR1
    __bic_SR_register_on_exit(LPM3_bits);     // Exit LPM3 on reti
}