#include <stdint.h>
#include <msp430.h>

void delay_ms(uint16_t ms) {
    while (ms--)
        __delay_cycles(1000);
}

void delay(int16_t count) {
    while (count--)
        __nop();
}

const int STEP = 5, COUNT = 500;

int main() {
    int16_t start, step, end, i;

    // Disable watchdog
    WDTCTL = WDTPW | WDTHOLD;

    // 1MHz internal timer
    BCSCTL1 = CALBC1_1MHZ;
    DCOCTL = CALDCO_1MHZ;

    // P2 (XOUT/XIN) as GPIO
    P2SEL = 0x00;
    
    P1OUT = 0x00;
    P1DIR = 0x01;

    start = 0;
    end = COUNT;
    step = STEP;

    /*while (1) {
        for (i = start; i != end; i += step) {
            P1OUT = 0x01;
            delay(i);
            P1OUT = 0x00;
            delay(COUNT - i);
        }

        start = COUNT - start;
        end = COUNT - end;
        step = -step;

        if (step > 0)
            delay_ms(500);
    }*/

    int16_t freq, afreq;

    TACTL = TASSEL1 | TACLR;
    P1SEL |= 0x04; // TA1 on P1.2
    P1DIR |= 0x04; // P1.2 output
    TACCTL0 &= ~CCIE;
    TACCTL1 = OUTMOD_7;
    TACTL |= MC0;

    //TACCR0 = 2272;
    //TACCR1 = 2272 / 2;
    
    while (1) {
        for (freq = -1000; freq < 1000; freq += 10) {
            afreq = 1000 + (freq < 0 ? -freq : freq);

            TACCR0 = afreq;
            TACCR1 = afreq / 2;

            delay_ms(5);
        }
    }

    return 0;
}