PSoC 4 "IDAC Sounds" main.c

#include <project.h>

const uint8_t sinTable[128] =
    {255,255,255,255,254,254,254,253,253,252,251,250,250,249,248,
     246,245,244,243,241,240,238,237,235,234,232,230,228,226,224,
     222,220,218,215,213,211,208,206,203,201,198,196,193,190,188,
     185,182,179,176,173,170,167,165,162,158,155,152,149,146,143,
     140,137,134,131,128,124,121,118,115,112,109,106,103,100,97,
     93,90,88,85,82,79,76,73,70,67,65,62,59,57,54,52,49,47,44,42,
     40,37,35,33,31,29,27,25,23,21,20,18,17,15,14,12,11,10,9,7,6,
     5,5,4,3,2,2,1,1,1,0,0,0};

volatile uint8_t timerTicked = 0;
uint8_t buttonState = 0;

uint32_t sinus(const uint8_t index) {

    // Avoid timing difference between conditions
    const uint8_t rIndex = 255 - index;

    if (index < 128) {
        return sinTable[index];
    } else {
        return sinTable[rIndex];
      } // else

} // sinus

CY_ISR(timerTick_Handler) {
    timerTicked = 1;
} // ISR

int main() {

    uint32_t a;

    CyGlobalIntEnable; /* Enable global interrupts. */

    timerTick_StartEx(timerTick_Handler);
    Timer_1_Start();

    for(;;)
    {

        if (timerTicked) {

            if (Button_Pin_Read() != buttonState) {

                // There are only two possibilities, so...
                buttonState = !buttonState;

                if (buttonState) {
                    IDAC_1_Stop();
                } else {
                    IDAC_1_Start();
                  } // else
                timerTicked = 0;

            } // if

        } // if (timerTicked)

        for (a = 0; a < 256; a++) {
            IDAC_1_SetValue(sinus(a));
            CyDelayUs(5);
        } // for
    }
} // main