PicoSynthesizer_Code/sketch/sketch.ino

482 lines
11 KiB
C++

#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "AudioTools.h"
/* =========================================================
CONFIG
========================================================= */
// ---- OLED ----
#define OLED_ADDR 0x3C
#define OLED_W 128
#define OLED_H 64
//Tracking Functions + Menues
bool funcKey = false;
float VOL = 0.5f;
//float decay = 1.0f;
float decay = 0.99998f;
Adafruit_SSD1306 display(OLED_W, OLED_H, &Wire);
// ----- Menu Functions
int sound = 0; //Default voice
String sounds[4] = {"Saw+Sine", "Sine", "Saw", "Triangle"};
int sound_count = sizeof(sounds)/sizeof(sounds[0]);
// Modes
int mode = 0;
String mode_names[3] = {"Vol", "Sou", "Oct"};
int mode_count = sizeof(mode_names)/sizeof(mode_names[0]);
// Octave
int octave = 4;
// ---- Audio ----
//constexpr uint32_t SAMPLE_RATE = 96000;
constexpr uint32_t SAMPLE_RATE = 44100;
constexpr uint8_t CHANNELS = 1;
constexpr uint8_t BITS = 16;
// ----- Reverb -----
constexpr int reverb_time = 200; // 200 ms.
constexpr int reverb_samples = (int)(reverb_time/1000*SAMPLE_RATE);
float reverbqueue[reverb_samples] = {};
float reverb_fade = 0.3f;
// ---- Matrix ----
const int X_PINS[4] = {8, 9, 10, 7};
const int Y_PINS[4] = {19, 20, 21, 22};
// ---- Synth ----
constexpr int MAX_VOICES = 200;
/* =========================================================
NOTES
========================================================= */
const char* noteNames[12] = {
"C","C#","D","D#",
"E","F","F#","G",
"G#","A","A#","B"
};
float noteFreq[12];
void initNotes() {
int octMult = powf(2, octave);
for (int i = 0; i < 12; i++) {
noteFreq[i] = 55.0f * octMult * powf(2.0f, i / 12.0f);
}
}
/* =========================================================
VOICES
========================================================= */
struct Voice {
bool active = false;
float freq = 0;
float phase1 = 0;
float phase2 = 0;
float env = 0;
float amp = 0;
};
Voice voices[MAX_VOICES];
void noteOn(float freq) {
for (auto &v : voices) {
if (!v.active) {
v.active = true;
v.freq = freq*(funcKey ? 1.25f : 1.0f);
v.env = VOL;
v.phase1 = 0.5f;
v.phase2 = 0.5f;
return;
}
}
}
void noteOff(float freq) {
for (auto &v : voices) {
if (v.active && fabs(v.freq - freq) < 0.01f) {
v.active = false;
}
}
}
float sineWave(float phase) {
// Convert phase (0-1) to radians (0-2π)
float radians = phase * 2.0f * 3.14156f;
// Generate sine value (-1 to 1)
float sineValue = sin(radians);
// Map from (-1 to 1) to (0 to 1)
float output = (sineValue + 1.0f) / 2.0f;
return output;
}
float handleReverb(float val){
for(int i = 0; i<reverb_samples-1; i++){
reverbqueue[i] = reverbqueue[i+1];
}
reverbqueue[reverb_samples-1] = val;
return reverbqueue[0]*reverb_fade;
}
float wavetable[16] = {0.2f,0.4f,0.9f,0.2f,0.4f,0.9f,0.2f,0.4f,0.9f,0.2f,0.4f,0.9f,0.2f,0.4f,0.9f,0.2f};
float wavetableInt[1024] = {};
int genWaveTable(){
int size = 16;
int newSize = 1024;
int div = newSize/size;
for(int s = 0; s<size-1; s++){
for(int i = 0; i<div; i++){
wavetableInt[(s*div)+i] = wavetable[s]+((wavetable[s+1]-wavetable[s])*(i/div));
}
}
return 0;
}
/* =========================================================
SYNTH STREAM
========================================================= */
class JunoStream : public Stream {
public:
uint8_t frame[4];
uint8_t index = 4;
float lp = 0.0f;
float cutoff = 1.0f*VOL;
float detune = 0.004f;
//float detune = 0.006f;
static constexpr int DELAY_SAMPLES = 960;
float delayL[DELAY_SAMPLES]{};
int delayIndex = 0;
float scope[128]{};
int scopeIndex = 0;
int available() override { return 4; }
int read() override {
if (index >= 4) {
generate();
index = 0;
}
return frame[index++];
}
int peek() override { return -1; }
size_t write(uint8_t) override { return 0; }
private:
void generate() {
float mix = 0.0f;
for (auto &v : voices) {
if (!v.active) continue;
/* SQUARE Wave
float square1 = (v.phase1>0.5f);
float square2 = (v.phase2>0.5f);
float osc = (saw1+saw2)/2.0f;
*/
float osc = 0.0f;
// Defined voices
switch(sound){
//SawSine
case 0:
osc = (sineWave(v.phase1)+sineWave(v.phase2)+wavetableInt[(int)floor(1024.0f*v.phase2)])/3.0f;
break;
//Sine
case 1:
osc = (sineWave(v.phase1)+sineWave(v.phase2))/2.0f;
break;
//Saw
case 2:
osc = (v.phase1);
break;
//Triangle
case 3:
osc = abs((v.phase1*2)-1.0f);
break;
}
//SINE
//osc = (osc+(v.phase1 > 0.5f)+(v.phase2 > 0.5f)) / 3.0f;
//float saw = sin(v.phase2 * (TWO_PI-PI));
//float osc = (saw1+saw2)/2.0f;
v.phase1 += v.freq / SAMPLE_RATE;
v.phase2 += (v.freq *1.0f * (1.25f + detune)) / SAMPLE_RATE;
//v.phase2 += (v.freq *1.25f * (1.0f + detune)) / SAMPLE_RATE;
if (v.phase1 >= 1) v.phase1 -= 1;
if (v.phase2 >= 1) v.phase2 -= 1;
v.amp = v.env;
v.env *= decay;
if (v.env < 0.0005f) v.active = false;
mix += osc * v.amp;
}
lp += cutoff * (mix - lp);
float out = lp * 0.4f;
//out = (handleReverb(out)+out)/2.0f;
int r = (delayIndex - 480 + DELAY_SAMPLES) % DELAY_SAMPLES;
float ch = out + delayL[r] * 0.6f;
delayL[delayIndex] = out;
delayIndex = (delayIndex + 1) % DELAY_SAMPLES;
scope[scopeIndex++] = ch;
scopeIndex &= 127;
int16_t pcm = (int16_t)(ch * 14000);
frame[0] = pcm & 0xFF;
frame[1] = pcm >> 8;
frame[2] = frame[0];
frame[3] = frame[1];
}
};
/* =========================================================
I2S
========================================================= */
I2SStream i2s;
JunoStream synth;
StreamCopy copier(i2s, synth);
/* =========================================================
MATRIX SCAN
========================================================= */
uint16_t scanMatrix() {
uint16_t state = 0;
for (int x = 0; x < 4; x++) {
digitalWrite(X_PINS[x], HIGH);
delayMicroseconds(5);
for (int y = 0; y < 4; y++) {
if (digitalRead(Y_PINS[y])) {
state |= (1 << (x + y * 4));
}
}
digitalWrite(X_PINS[x], LOW);
}
return state;
}
/* =========================================================
OLED DRAWING
========================================================= */
void drawPads(uint16_t keys) {
const int w = 30, h = 14;
for (int r = 0; r < 3; r++) {
for (int c = 0; c < 4; c++) {
int i = c + r * 4;
int x = c * w + 2;
int y = r * h + 2;
bool on = keys & (1 << i);
display.drawRect(x, y, w - 2, h - 2, SSD1306_WHITE);
if (on) display.fillRect(x + 1, y + 1, w - 4, h - 4, SSD1306_WHITE);
display.setTextColor(on ? SSD1306_BLACK : SSD1306_WHITE);
display.setCursor(x + 4, y + 2);
display.print(noteNames[i]);
}
}
}
void drawScope() {
int mid = 35; // middle of scope on Y position
int height = 20;
for (int x = 0; x < 127; x++) {
int i1 = (synth.scopeIndex + x) & 127;
int i2 = (i1 + 1) & 127;
display.drawLine(
x,
mid - synth.scope[i1] * 20,
x + 1,
mid - synth.scope[i2] * 20,
SSD1306_WHITE
);
}
}
void drawVoices() {
int y = 62;
for (int i = 0; i < MAX_VOICES; i++) {
int x = i * 20;
if (voices[i].active) {
display.fillRect(x, y - 6, 16, 6, SSD1306_WHITE);
} else {
display.drawRect(x, y - 6, 16, 6, SSD1306_WHITE);
}
}
}
void drawVolumebar() {
display.fillRect(0,60,(128*VOL), 64, SSD1306_WHITE);
}
// Draws the current Synthesizer sound preset
void drawInfo(){
// Show current Sound preset
display.setTextSize(1);
display.setTextColor(SSD1306_WHITE);
display.setCursor(0,6);
display.print(sounds[sound]);
// Show current menu mode
display.setCursor(64,6);
display.print("Set:");
display.setCursor(100,6);
display.print(mode_names[mode]);
display.setCursor(90,18);
display.print("Oct:"+String(octave));
}
void updateOLED(uint16_t keys) {
display.clearDisplay();
//drawPads(keys);
drawScope();
drawInfo();
//drawVoices();
drawVolumebar();
display.display();
}
/* =========================================================
SETUP
========================================================= */
void setup() {
genWaveTable();
for (int i = 0; i < 4; i++) {
pinMode(X_PINS[i], OUTPUT);
digitalWrite(X_PINS[i], LOW);
pinMode(Y_PINS[i], INPUT); // external pulldowns
}
// Set up Display
Wire.setSDA(4); // GP4 (pin 6)
Wire.setSCL(5); // GP5 (pin 7)
Wire.begin();
display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
display.clearDisplay();
initNotes();
auto cfg = i2s.defaultConfig(TX_MODE);
cfg.sample_rate = SAMPLE_RATE;
cfg.bits_per_sample = BITS;
cfg.channels = CHANNELS;
cfg.pin_bck = 16;
cfg.pin_ws = 17;
cfg.pin_data = 18;
i2s.begin(cfg);
}
/* =========================================================
LOOP
========================================================= */
static uint16_t lastKeys = 0;
static uint32_t lastUI = 0;
uint16_t keys = 0;
uint16_t changed = keys ^ lastKeys;
void loop() {
copier.copy();
}
void loop1(){
keys = scanMatrix();
changed = keys ^ lastKeys;
for (int i = 0; i < 16; i++) {
if (changed & (1 << i)) {
if (i < 12){
if ((keys & (1 << i))){
noteOn(noteFreq[i]);
}else{
noteOff(noteFreq[i]);
}
}else{
funcKey = (keys & (1 << 12));
// If Enter key pressed
if(keys & (1 << 14)){
mode = mode+1;
mode = mode % mode_count;
}
// If Left key is pressed
if(keys & (1 << 13)){
switch(mode){
case 0: // Volume
if(VOL>0.1f){VOL-=0.1f;}
break;
case 1: // Sound
sound = sound - 1;
if(sound<0){sound = sound_count-1;}
break;
case 2: // Octave
if(octave>1){octave = octave-1;}
initNotes();
break;
}
// If Right key is pressed
}else if((keys & (1 << 15))){
switch(mode){
case 0: // Volume
if(VOL<1.0f){VOL+=0.1f;}
break;
case 1: // Sound
sound = sound + 1;
sound = sound % sound_count;
break;
case 2: // Octave
if(octave<8){octave = octave + 1;}
initNotes();
break;
}
}
//menuButton(i-12);
}
}
}
lastKeys = keys;
if (millis() - lastUI > 30) {
updateOLED(keys);
lastUI = millis();
}
}