pwm audio

This commit is contained in:
Jack Humbert 2016-01-11 16:53:33 -05:00
parent 11ce694557
commit 29de37d5c0
13 changed files with 600 additions and 190 deletions

View file

@ -1,11 +1,20 @@
#include "beeps.h"
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <avr/io.h>
#include "beeps.h"
#include "keymap_common.h"
#include "wave.h"
#define PI 3.14159265
#define SAMPLE_DIVIDER 70
#define SAMPLE_RATE (2000000.0/SAMPLE_DIVIDER/256)
// Resistor value of 1/ (2 * PI * 10nF * (2000000 hertz / SAMPLE_DIVIDER / 10)) for 10nF cap
void delay_us(int count) {
while(count--) {
_delay_us(1);
@ -15,7 +24,7 @@ void delay_us(int count) {
int voices = 0;
double frequency = 0;
int volume = 0;
int position = 0;
long position = 0;
double frequencies[8] = {0, 0, 0, 0, 0, 0, 0, 0};
int volumes[8] = {0, 0, 0, 0, 0, 0, 0, 0};
@ -23,6 +32,19 @@ bool sliding = false;
#define RANGE 1000
volatile int i=0; //elements of the wave
// uint8_t sine[128];
// uint8_t tri[128];
// uint8_t squ[128];
// uint8_t* sine_start;
// uint8_t* sine_end;
// uint8_t* tri_start;
// uint8_t* tri_end;
// uint8_t* s_start;
// uint8_t* s_end;
// uint8_t* s_ptr;
void beeps() {
play_notes();
@ -36,8 +58,7 @@ void send_freq(double freq, int vol) {
void stop_all_notes() {
voices = 0;
TCCR3A = 0;
TCCR3B = 0;
TIMSK0 &= ~_BV(OCIE0A);
frequency = 0;
volume = 0;
@ -48,6 +69,7 @@ void stop_all_notes() {
}
void stop_note(double freq) {
freq = freq / SAMPLE_RATE;
for (int i = 7; i >= 0; i--) {
if (frequencies[i] == freq) {
frequencies[i] = 0;
@ -64,151 +86,176 @@ void stop_note(double freq) {
if (voices < 0)
voices = 0;
if (voices == 0) {
TCCR3A = 0;
TCCR3B = 0;
TIMSK0 &= ~_BV(OCIE0A);
frequency = 0;
volume = 0;
} else {
double freq = frequencies[voices - 1];
int vol = volumes[voices - 1];
double starting_f = frequency;
if (frequency < freq) {
sliding = true;
for (double f = frequency; f <= freq; f += ((freq - frequency) / 500.0)) {
send_freq(f, vol);
for (double f = starting_f; f <= freq; f += ((freq - starting_f) / 500.0)) {
frequency = f;
}
sliding = false;
} else if (frequency > freq) {
sliding = true;
for (double f = frequency; f >= freq; f -= ((frequency - freq) / 500.0)) {
send_freq(f, vol);
for (double f = starting_f; f >= freq; f -= ((starting_f - freq) / 500.0)) {
frequency = f;
}
sliding = false;
}
send_freq(freq, vol);
// send_freq(freq, vol);
frequency = freq;
volume = vol;
}
}
void init_notes() {
// TCCR1A = (1 << COM1A1) | (0 << COM1A0) | (1 << WGM11) | (1 << WGM10);
// TCCR1B = (1 << COM1B1) | (0 << COM1A0) | (1 << WGM13) | (1 << WGM12) | (0 << CS12) | (0 << CS11) | (1 << CS10);
// DDRC |= (1<<6);
// for(int i = 0; i < 128; i++) {
// sine[i] = sin(i * PI / 64) * 128 + 128;
// tri[i] = 256 - abs((i - 64) * 4);
// }
// sine_start = &sine;
// sine_end = &sine + 128;
// tri_start = &tri;
// tri_end = &tri + 128;
// TCCR3A = (1 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
// TCCR3B = (1 << WGM33) | (1 << WGM32) | (0 << CS32) | (0 << CS31) | (1 << CS30);
// ICR3 = 0xFFFF;
// OCR3A = (int)((float)wave[i]*ICR3/RANGE); //go to next array element
// new
// cli();
PLLFRQ = _BV(PDIV2);
PLLCSR = _BV(PLLE);
while(!(PLLCSR & _BV(PLOCK)));
PLLFRQ |= _BV(PLLTM0); /* PCK 48MHz */
/* Init a fast PWM on Timer4 */
TCCR4A = _BV(COM4A0) | _BV(PWM4A); /* Clear OC4A on Compare Match */
TCCR4B = _BV(CS40); /* No prescaling => f = PCK/256 = 187500Hz */
OCR4A = 0;
// /* Enable interrupt on timer2 == 127, with clk/8 prescaler. At 16MHz,
// this gives a timer interrupt at 15625Hz. */
// TIMSK3 = (1 << OCIE3A);
// /* clear/reset timer on match */
// // TCCR3A = 1<<WGM31 | 0<<WGM30; CTC mode, reset on match
// // TCCR3B = 0<<CS32 | 1<<CS31 | 0<<CS30; /* clk, /8 prescaler */
// TCCR3A = (1 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
// TCCR3B = (0 << WGM33) | (0 << WGM32) | (0 << CS32) | (0 << CS31) | (1 << CS30);
/* Enable the OC4A output */
DDRC |= _BV(PORTC6);
// TCCR1A = (1 << COM1A1) | (0 << COM1A0) | (1 << WGM11) | (0 << WGM10);
// TCCR1B = (1 << WGM12) | (0 << CS12) | (0 << CS11) | (1 << CS10);
// // SPCR = 0x50;
// // SPSR = 0x01;
// DDRC |= (1<<6);
// // ICR3 = 0xFFFF;
// // OCR3A=80;
// PORTC |= (1<<6);
// sei();
/* First disable the timer overflow interrupt while we're configuring */
// TIMSK0 &= ~(1<<TOIE0);
// /* Configure timer4 in normal mode (pure counting, no PWM etc.) */
// TCCR0A &= ~((1<<WGM01) | (1<<WGM00));
// TCCR0B &= ~(1<<WGM02);
// /* Disable Compare Match A interrupt enable (only want overflow) */
// TIMSK0 &= ~(1<<OCIE0A);
// TCCR0B |= (1<<CS01); // Set bits
// TCCR0B &= ~(1<<CS00) | ~(1<<CS02); // Clear bit
// /* Save value globally for later reload in ISR */
// tcnt0 = 45 - 1;
// /* Finally load end enable the timer */
// TCNT0 = tcnt0;
// TIMSK0 |= (1<<TOIE0);
}
// #define highByte(c) ((c >> 8) & 0x00FF)
// #define lowByte(c) (c & 0x00FF)
int max = 0xFF;
float sum = 0;
int value = 128;
float place = 0;
ISR(TIMER3_COMPA_vect) {
if (ICR3 > 0 && !sliding) {
switch (position) {
case 0: {
int duty = (((double)F_CPU) / (frequency));
ICR3 = duty; // Set max to the period
OCR3A = duty >> 1; // Set compare to half the period
break;
}
case 1: {
int duty = (((double)F_CPU) / (frequency*2));
ICR3 = duty; // Set max to the period
OCR3A = duty >> 1; // Set compare to half the period
break;
}
case 2: {
int duty = (((double)F_CPU) / (frequency*3));
ICR3 = duty; // Set max to the period
OCR3A = duty >> 1; // Set compare to half the period
break;
}
}
position = (position + 1) % 3;
}
// /* OCR2A has been cleared, per TCCR2A above */
// // OCR3A = 127;
// // pos1 += incr1;
// // pos2 += incr2;
// // pos3 += incr3;
// // sample = sinewave[highByte(pos1)] + sinewave[highByte(pos2)] + sinewave[highByte(pos3)];
// // OCR3A = sample;
ISR(TIMER0_COMPA_vect) {
// OCR3A=pgm_read_byte(&sinewave[pos1]);
// pos1++;
// // PORTC &= ~(1<<6);
// /* buffered, 1x gain, active mode */
// // SPDR = highByte(sample) | 0x70;
// // while (!(SPSR & (1<<SPIF)));
// value = *(sine_start+=(long)frequencies[0]);
// OCR4A = value;
// if (sine_start >= sine_end) {
// sine_start = &sine[(sine_start - sine_end) % 128];
// }
// // SPDR = lowByte(sample);
// // while (!(SPSR & (1<<SPIF)));
// // PORTC |= (1<<6);
// OCR4A = pgm_read_byte(sine_start);
// // sine_start = &sine[(sine_start - &sine[0] + (int)frequencies[0]) % 128];
// sine_start += (int)frequencies[0];
// if (sine_start >= sine_end) {
// sine_start = &sine[(sine_start - sine_end) % 128];
// }
// OCR4A = pgm_read_byte(s_ptr);
// s_ptr = s_start + (uint8_t)place;
// OCR4A = pgm_read_byte(s_ptr);
// SINE
OCR4A = pgm_read_byte(&sinewave[(uint16_t)place]);
// SQUARE
// if (((int)place) >= 1024){
// OCR4A = 0xFF;
// } else {
// OCR4A = 0x00;
// }
// SAWTOOTH
// OCR4A = (int)place / 4;
// TRIANGLE
// if (((int)place) >= 1024) {
// OCR4A = (int)place / 2;
// } else {
// OCR4A = 2048 - (int)place / 2;
// }
place += frequency;
if (place >= SINE_LENGTH)
place -= SINE_LENGTH;
}
ISR(TIMER0_COMPB_vect)
{
/* Disable the interrupt */
TIMSK0 &= ~_BV(OCIE0B);
}
void play_note(double freq, int vol) {
freq = freq / SAMPLE_RATE;
if (freq > 0) {
DDRC |= (1<<6);
TCCR3A = (1 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (0 << WGM30);
TCCR3B = (1 << WGM33) | (1 << WGM32) | (0 << CS32) | (1 << CS31) | (0 << CS30);
// TCCR3A = (1 << COM3A1) | (0 << COM3A0) | (1 << WGM31) | (1 << WGM30);
// TCCR3B = (0 << WGM33) | (1 << WGM32) | (0 << CS32) | (0 << CS31) | (1 << CS30);
// TIMSK3 = 0x0;
if (frequency != 0) {
double starting_f = frequency;
if (frequency < freq) {
for (double f = frequency; f <= freq; f += ((freq - frequency) / 500.0)) {
send_freq(f, vol);
for (double f = starting_f; f <= freq; f += ((freq - starting_f) / 500.0)) {
frequency = f;
}
} else if (frequency > freq) {
for (double f = frequency; f >= freq; f -= ((frequency - freq) / 500.0)) {
send_freq(f, vol);
for (double f = starting_f; f >= freq; f -= ((starting_f - freq) / 500.0)) {
frequency = f;
}
}
}
send_freq(freq, vol);
// send_freq(freq, vol);
frequency = freq;
volume = vol;
frequencies[voices] = frequency;
volumes[voices] = volume;
voices++;
// position = 0;
// TCNT0 = 0;
}
// ICR3 = 0xFFFF;
// for (int i = 0; i < 10000; i++) {
@ -218,6 +265,18 @@ void play_note(double freq, int vol) {
// TCCR3A = 0;
// TCCR3B = 0;
TIMSK0 &= ~_BV(OCIE0A) | ~_BV(OCIE0B);
TCCR0A = _BV(WGM01);
TCCR0B = _BV(CS01);
OCR0A = SAMPLE_DIVIDER - 1;
OCR0B = 1;
TIMSK0 |= _BV(OCIE0A);
// sei();
}
// void note(int x, float length) {