124 lines
2.4 KiB
C++
124 lines
2.4 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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int note = 0;
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// int pitch[] = { 0, 1, 2, 3, 4, 5, 6, 7, 0, 1, 2, 3, 4, 5, 6, 7 };
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// float dur[] = { 1, 0.5, 0.25, 0.1, 1, 0.5, 0.25, 0.1,1, 0.5, 0.25, 0.1,1, 0.5, 0.25, 0.1 };
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int pitch[] = { 8, -1, -1, -1, -1,-1, -1, -1, -1,-1, 8, -1, -1, -1, -1, -1, };
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float dur[] = { 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 };
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int phrase = 16;
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int s;
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int beat_m = 100; // fix me coordinate with timer code
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bool noteon = false;
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int beat = false;
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long notestart, notedur;
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void setup() {
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Serial.begin(115200);
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cli();
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//set timer1 interrupt at 1Hz
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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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// set compare match register for 1hz increments
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//OCR1A = 15624;// = (16*10^6) / (1*1024) - 1 (must be <65536)
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//OCR1A = 7812;// = (16*10^6) / (1*1024) - 1 (must be <65536)
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OCR1A = 800;
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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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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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Serial.println("hello");
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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 note
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beat = true;
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}
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void loop() {
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long now = millis();
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if( beat ) {
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beat = false;
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if( pitch[s] > -1 ) {
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notestart = millis();
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notedur = round(beat_m * dur[s]);
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noteOn(pitch[s]);
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noteon = true;
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}
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s += 1;
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if( s == phrase ) {
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s = 0;
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}
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} else {
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if( noteon ) {
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if( now - notestart > notedur ) {
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noteOff();
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noteon = false;
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}
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}
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}
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}
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void noteOn(int note) {
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if( note > -1 ) {
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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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}
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}
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void noteOff() {
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Serial.println("off");
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mcp.setChannelValue(MCP4728_CHANNEL_B, 0);
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}
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