139 lines
3.7 KiB
C
139 lines
3.7 KiB
C
#include "msp430.h"
|
|
#include <stdlib.h>
|
|
#include <stdbool.h>
|
|
|
|
#define c 3822
|
|
#define dflat 3608
|
|
#define d 3405
|
|
#define eflat 3214
|
|
#define e 3034
|
|
#define f 2863
|
|
#define gflat 2703
|
|
#define g 2551
|
|
#define aflat 2408
|
|
#define a 2273
|
|
#define bflat 2145
|
|
#define b 2025
|
|
#define cc 1911
|
|
#define n 0
|
|
|
|
#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 // microseconds (us) in a centisecond (cs)
|
|
#define CSINT 6 // centiseconds storable in int of microseconds
|
|
#define USINT 60000 // CSINT in microseconds
|
|
|
|
#define DUTY 250
|
|
#define DELAY 1000 // input sample delay in microseconds
|
|
#define MAXNOTES 64 // record at most 64 notes (arbitrary)
|
|
|
|
// max length of note is 0xFFFF centiseconds = approx. 10 minutes
|
|
unsigned int rec[MAXNOTES]; // notes recorded
|
|
unsigned int len[MAXNOTES]; // length of each note in centiseconds
|
|
|
|
volatile bool recording = true;
|
|
volatile unsigned int notes = 1;
|
|
volatile unsigned int us = 0;
|
|
volatile unsigned int cs = 0;
|
|
|
|
unsigned int scale[16] = {
|
|
c, dflat, d, eflat, e, f, gflat, g, aflat, a, bflat, b, cc, c, dflat, eflat
|
|
};
|
|
|
|
unsigned int whole[8] = {
|
|
c, d, e, f, g, a, b, cc
|
|
};
|
|
|
|
void play(unsigned int note) {
|
|
CCR0 = note;
|
|
CCR1 = note == n ? 0 : DUTY;
|
|
}
|
|
|
|
void playback() {
|
|
for (unsigned int i = 0; i < notes; i++) {
|
|
play(rec[i]);
|
|
for (unsigned int j = 0; j < len[i]; j++) {
|
|
__delay_cycles(CSUS);
|
|
}
|
|
}
|
|
}
|
|
|
|
void save_length(unsigned int position) {
|
|
len[position] = cs + (us + TAR)/CSUS;
|
|
cs = us = TAR = 0; // reset all counts
|
|
}
|
|
|
|
void record() {
|
|
unsigned int note;
|
|
TAR = 0;
|
|
P1OUT |= LED1;
|
|
while (recording && notes < MAXNOTES) {
|
|
note = scale[P2IN & 0xF];
|
|
if (note != rec[notes - 1]) {
|
|
save_length(notes - 1);
|
|
rec[notes] = note;
|
|
play(note);
|
|
notes++;
|
|
}
|
|
__delay_cycles(DELAY);
|
|
}
|
|
}
|
|
|
|
void main(void) {
|
|
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
|
|
|
|
P2DIR = 0; // P2 all input
|
|
P2REN = 0xF; // P2 inputs resistor enable
|
|
P2OUT = 0; // P2 resistor pulldown
|
|
P1DIR = OUTPUT | LED1; // P1.6, P1.0 output (P1.3 input)
|
|
P1SEL |= OUTPUT; // P1.6 to TA0.1
|
|
P1REN = BUTTON; // button resistor enable
|
|
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();
|
|
record();
|
|
__bis_SR_register(LPM0_bits);
|
|
}
|
|
|
|
#if defined(__TI_COMPILER_VERSION__)
|
|
#pragma vector=TIMER0_A0_VECTOR
|
|
__interrupt void timer0_a0_isr(void)
|
|
#else
|
|
void __attribute__ ((interrupt(TIMER0_A0_VECTOR))) timer0_a0_isr (void)
|
|
#endif
|
|
{
|
|
unsigned int us_left = USINT - us; // count up to USINT microseconds in us
|
|
if (us_left < TACCR0) {
|
|
cs += CSINT; // add centiseconds to cs count
|
|
us = TACCR0 - us_left; // save overflow
|
|
} else {
|
|
us += TACCR0; // add microseconds to us count
|
|
}
|
|
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
|
|
{
|
|
if (recording) {
|
|
save_length(notes);
|
|
recording = false;
|
|
P1OUT &= ~LED1;
|
|
TACCTL0 &= ~CCIE; // disable interrupts for clock
|
|
}
|
|
playback();
|
|
P1IFG &= ~BUTTON; // set interrupt flag to 0
|
|
}
|