146 lines
2.8 KiB
C++
146 lines
2.8 KiB
C++
// Better sequencer which uses interrupts
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#include <Adafruit_MCP4728.h>
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#include <Wire.h>
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Adafruit_MCP4728 mcp;
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float tuning[37];
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float voltrange = 4.85; // measured this, probably not accurate
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float octave = 4096.0 / voltrange; // number of DAC steps in an octave
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// melody
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// int pitch[] = { 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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// -1, -1, -1, -1, -1, -1, -1, -1,-1, -1, -1, -1,2, -1, -1, -1, };
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// int dur[] = { 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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// 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, };
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// hi hat
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int pitch[] = { 1, -1, 3, -1, 4, -1, 5, -1, };
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int note = 0;
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int phrase = 8;
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int grains_n = 12;
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int grainc = 0;
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int grainsize = 20;
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int s;
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int bpm = 9000;
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float beat_s = 60.0 / (float)bpm;
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float note_s = beat_s * grains_n;
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float beat_m = 1000.0 * beat_s;
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bool noteon = false;
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int beat = false;
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long notestart, notedur, barstart;
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int target, slew;
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float decay = 0.1;
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void setup() {
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Serial.begin(115200);
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float freq = (float)bpm / 60.0;
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int ocr = round(16000000.0 / (1024.0 * freq )) - 1;
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Serial.println(ocr);
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if( ocr < 65536 ) {
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cli();
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TCCR1A = 0;// set entire TCCR1A register to 0
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TCCR1B = 0;// same for TCCR1B
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TCNT1 = 0;//initialize counter value to 0
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OCR1A = ocr; //ocr;
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// turn on CTC mode
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TCCR1B |= (1 << WGM12);
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// Set CS10 and CS12 bits for 1024 escaler
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TCCR1B |= (1 << CS12) | (1 << CS10);
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// enable timer compare interrupt
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TIMSK1 |= (1 << OCIE1A);
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sei();
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} else {
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Serial.println("BPM out of range");
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}
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if (!mcp.begin(0x64)) {
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while (1) {
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delay(100);
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}
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}
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// randomSeed(analogRead(A0));
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mcp.setSpeed(800000L);
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make_tuning(12);
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note=0;
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notestart=millis();
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}
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void make_tuning(int edo) {
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float n0 = 0;
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float edof = (float)edo;
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for( int i = 0; i < 37; i++ ) {
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tuning[i] = round(n0 + octave * (float)i / edof);
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}
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}
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ISR(TIMER1_COMPA_vect){ // called once every beat
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beat = true;
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}
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bool play_grain(int dur) {
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return true;
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// return random(0, 1000) > (float)dur * decay;
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}
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void loop() {
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int now = millis();
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if( beat ) {
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beat = false;
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noteOn(pitch[s], now - notestart);
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grainc++;
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if( grainc > grains_n ) {
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grainc = 0;
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s += 1;
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if( s == phrase ) {
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s = 0;
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notestart = now;
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}
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grainc = 0;
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Serial.println(s);
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}
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} else {
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if( noteon && now - notestart > grainsize ) {
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noteOff();
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}
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}
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}
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void noteOn(int note, int dur) {
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Serial.println("noteOn");
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if( note > -1 && play_grain(dur) ) {
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mcp.setChannelValue(MCP4728_CHANNEL_A, tuning[note]);
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mcp.setChannelValue(MCP4728_CHANNEL_B, 4095);
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noteon = true;
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}
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}
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void noteOff() {
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mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
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noteon = false;
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Serial.println("noteOff");
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}
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