lab10.c

#include <hidef.h>      /* common defines and macros */
#include "derivative.h"      /* derivative-specific definitions */
#include <math.h>



int notes[16]= {60,62,64,65,67,69,71,0,72,74,76,77,79,81,83,84}; //key to note lookup table


void initializePorts()
{
    DDRA = 0xFF;               //Turn LEDs on
    DDRT = 0xF0;               //Set input key
    DDRP = 0x0F;               //Set output key
    PPST = 0xF0;
    PERT = 0x0F;

    TIOS = 0xC0;

    TSCR2_PR = 0x1;
    TSCR2_TOI = 0x0;

    TCTL1 = 0x50;
    TCTL2 = 0x00;

    PORTA = 0x00;              //LEDs off
    PTP = 0xFE;
    PTT = 0x0F;
}

//hex keypad routine
byte getkey () {
    int i;
    byte scan_code = 0xff; //off code
    PTP = 0x0E ;            //0111

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

        if (PTT_PTT0 == 0) {
            scan_code = i*4+0;
            break;
        }
        else if (PTT_PTT1 == 0) {
            scan_code = i*4+1;
            break;
        }
        else if (PTT_PTT2 == 0) {
            scan_code = i*4+2;
            break;
        }
        else if (PTT_PTT3 == 0) {
            scan_code = i*4+3;

            break;
        }
        PTP = PTP<<1;          //shift PTP to check the next row PTP *2
        PTP = PTP+1;            //add1 1 to PTP
    }

    return scan_code;
}

void leds (byte scan_code) {
    PORTA = scan_code;
    while (getkey()==scan_code) {  //block LEDs until key release
    };
}

void play(int note, byte scan_code)
{
    int tc;
    int f;
    float noteRaised = 1.05946;  //Midi note raised to the 12th root (2^(1/12)

    f = 27.5 * pow(noteRaised, (note - 21) );
    tc = 1000000 / (2 * f);

    TSCR1 = 0x80; //enable timer

    while (getkey()==scan_code) {  //while the button is pressed
        if (TFLG1_C7F == 1) // if PT7 has toggled:
        {
            TC7 += tc;
            // set next half-period count
            TFLG1 = 0x80; // clear channel 7 compare flag
        }
        if (TFLG1_C6F == 1)
        {
            TC6 += tc;
            TFLG1 = 0x40;
        }
    }; //end while

    TSCR1 = 0x00; //disable timer?
}


void keypad_button_pressed(byte scan_code)
{
    //put functions you want to execute when a button is pressed here:
    play(notes[scan_code], scan_code);
    leds(notes[scan_code]);
}

void handle_keypad()
{
    byte scan_code;
    scan_code = getkey ();

    if (scan_code != 0xff) //if keyboard press
        keypad_button_pressed(scan_code);
}

void main(void) {

    initializePorts();

    while(1)
    {
        handle_keypad();
    }

    EnableInterrupts;


    for(;;) {
        _FEED_COP(); /* feeds the dog */
    } /* loop forever */
    /* please make sure that you never leave main */
}