It works!

lab3/piano.c

@@ -1,5 +1,6 @@
 #include "msp430.h"
 #include <stdlib.h>
+#include <stdbool.h>
 
 #define c     3822
 #define dflat 3608
@@ -16,91 +17,83 @@
 #define cc    1911
 #define n     0
 
-unsigned int hbd[30] = {
-    c,  n, c, 
-    d,  c, f,
-    e,  c, n, c,
-    d,  c, g,
-    f,  c, n, c,
-    cc, a, f,
-    e,  d, bflat, n, bflat,
-    a,  f, g,
-    f,  n
-};
-unsigned int hbd_lengths[30] = {
-    1, 1, 1, 
-    3, 3, 3, 
-    6, 1, 1, 1,
-    3, 3, 3, 
-    6, 1, 1, 1, 
-    3, 3, 3, 
-    3, 6, 1, 1, 1, 
-    3, 3, 3, 
-    6, 3
-};
+#define LED1   BIT0
+#define BUTTON BIT3
+#define OUTPUT BIT6
+
+// CSINT should be 256^2 / 10 000 = 65 536 / 10 000 = 6
+// USINT should be 60 000
+#define CSUS  10000     // CSUS microseconds (us) in a centisecond (cs)
+#define CSINT 6         // centiseconds storable in int of microseconds
+#define USINT 60000     // CSINT in microseconds
+
+#define MAXNOTES 64     // record at most 64 notes (arbitrary)
+
+volatile bool recording = true;
+volatile unsigned int us = 0;
+volatile unsigned int cs = 0;
 
 unsigned int scale[13] = {
     c, dflat, d, eflat, e, f, gflat, g, aflat, a, bflat, b, cc
 };
-unsigned int scale_lengths[13] = {
-    2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
-};
 
 unsigned int whole[8] = {
     c, d, e, f, g, a, b, cc
 };
 
 void play(unsigned int note) {
-    if (note != 0) {
-        CCR0 = note;
-        CCR1 = 100;
-    } else {
-        CCR1 = 0;
-    }
+    CCR0 = note;
+    CCR1 = note == n ? 0 : 100;
 }
 
-void sing(unsigned int* song, unsigned int* song_lengths, unsigned int length) {
+void sing(unsigned int* song, unsigned int* lengths, unsigned int length) {
     for (int i = 0; i < length; i++) {
         play(song[i]);
-        for (int j = 0; j < song_lengths[i]; j++) {
-            __delay_cycles(0x200);
+        for (int j = 0; j < lengths[i]; j++) {
+            __delay_cycles(CSUS);
         }
     }
 }
 
-unsigned int us = 0;
-unsigned int cs = 0;
-
-void main(void) {
-    WDTCTL  = WDTPW + WDTHOLD;      // Stop WDT
-  
-    P1DIR   = BIT6;                 // set P1.6 to output
-    P1SEL  |= BIT6;                 // P1.6 to TA0.1
-  
-    CCTL1   = OUTMOD_7;             // CCR1 reset/set
-    TACTL   = TASSEL_2 | MC_1;      // SMCLK, up to CCR0
-    TACCTL0 = CCIE;                 // enable interrupt
-    __enable_interrupt();
-    
-    unsigned int rec[10] = {n, b, b, b, b, b, b, b, b, b};
-    unsigned int rec_len[10] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
-    unsigned int position = 1;
+unsigned int record(unsigned int* song, unsigned int* lengths) {
+    unsigned int pos = 1;
+    unsigned int note;
     TAR = 0;
-    while (position < 10) {
-        if (whole[P1IN & 0xF] != rec[position - 1]) {
-            rec_len[position - 1] = cs + (us + TAR)/10000;
-            rec[position] = whole[P1IN & 0xF];
-            play(rec[position]);
+    P1OUT |= LED1;
+    while (recording) {
+        note = whole[P2IN & 0xF];
+        if (note != song[pos - 1]) {
+            lengths[pos - 1] = cs + (us + TAR)/CSUS;
+            song[pos] = note;
+            play(note);
             cs = us = TAR = 0;
-            position++;
+            pos++;
         }
         __delay_cycles(0x200);
     }
+    P1OUT &= ~LED1;
+    return pos;
+}
 
-    sing(rec, rec_len, 10);
-    //clear();
-    //sing(hbd, hbd_lengths, 30);
-    //sing(scale, scale_lengths, 13);
+void main(void) {
+    WDTCTL  = WDTPW + WDTHOLD;      // Stop WDT
+
+    P2DIR   = 0;                    // P2 all input
+    P1DIR   = OUTPUT | LED1;        // P1.6, P1.0 output (P1.3 input)
+    P1SEL  |= OUTPUT;               // P1.6 to TA0.1
+    P1REN   = BUTTON;               // button resistor pullup/pulldown
+    P1IE    = BUTTON;               // enable button interrupt
+
+    CCTL1   = OUTMOD_7;             // CCR1 reset/set
+    TACTL   = TASSEL_2 | MC_1;      // SMCLK (1 MHz) count up to CCRO
+    TACCTL0 = CCIE;                 // enable clock  interrupt
+
+    __enable_interrupt();
+    
+    unsigned int rec[MAXNOTES];
+    unsigned int len[MAXNOTES];
+    unsigned int length = record(rec, len);
+    sing(rec, len, length);
 }
 
 #if defined(__TI_COMPILER_VERSION__)
@@ -110,12 +103,25 @@ __interrupt void timer0_a0_isr(void)
     void __attribute__ ((interrupt(TIMER0_A0_VECTOR))) timer0_a0_isr (void)
 #endif
 {
-    unsigned int us_left = 60000 - us;  // count up to 60 000 microseconds in us
-    if (us_left > TACCR0) {
-        cs += 6;                        // add six centiseconds to count
-        us = TACCR0 - us_left;          // save overflow
+    unsigned int us_left = USINT - us;  // count up to USINT microseconds in us
+    if (us_left < TACCR0) {
+        cs += CSINT;            // add centiseconds to count
+        us = TACCR0 - us_left;  // save overflow
     } else {
         us += TACCR0;
     }
-    TACCTL0 &= ~CCIFG;                  // set interrupt flag to 0
-} 
+    TACCTL0 &= ~CCIFG;          // set interrupt flag to 0
+}
+
+#if defined(__TI_COMPILER_VERSION__)
+#pragma vector=PORT1_VECTOR
+__interrupt void port1_isr(void)
+#else
+  void __attribute__ ((interrupt(PORT1_VECTOR))) port1_isr (void)
+#endif
+{
+    recording = false;          // stop recording
+    P1OUT ^=  BIT0;
+    P1IFG &= ~BIT3;             // set interrupt flag to 0
+    P1IE  &= ~BIT3;             // disable interrupts for button
+}