122 lines
3.5 KiB
C++
122 lines
3.5 KiB
C++
/* Based on the "CHORUS for Stompshield" adapted from pedal shield, and reconverted for pedalSHIELD UNO*/
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//defining harware resources.
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#define LED 13
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#define FOOTSWITCH 12
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#define TOGGLE 2
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#define PUSHBUTTON_1 A5
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#define PUSHBUTTON_2 A4
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//defining the output PWM parameters
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#define PWM_FREQ 0x00FF // pwm frequency - 31.3KHz
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#define PWM_MODE 0 // Fast (1) or Phase Correct (0)
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#define PWM_QTY 2 // 2 PWMs in parallel
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//defining buttons parameters
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#define B_MAX 100 // max value for rotary encoder input (min freq)
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#define B_MIN 1 // min value for rotary encoder input (max freq)
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//defining FX parameters
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#define MAX_DELAY 240
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#define MIN_DELAY 200
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uint16_t sDelayBuffer0[MAX_DELAY*2];
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uint16_t sDelayBuffer1[MAX_DELAY*2];
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unsigned int DelayCounter = 5;
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unsigned int Delay_Depth = 25;
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unsigned int count_up=1;
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int p;
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int POT0 = 1;
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unsigned int location = 0; // incoming data buffer pointer
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byte button; // button checking timer
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byte last_state; // last rotary encoder state
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byte counter = 1; // rotary encoder rotation counter (and start value)
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unsigned int fractional = 0x00; // fractional sample position
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int data_buffer; // temporary data storage to give a 1 sample buffer
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int counter2=0; //buttons timer counter
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void setup() {
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//setup IO
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pinMode(FOOTSWITCH, INPUT_PULLUP);
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pinMode(TOGGLE, INPUT_PULLUP);
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pinMode(PUSHBUTTON_1, INPUT_PULLUP);
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pinMode(PUSHBUTTON_2, INPUT_PULLUP);
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pinMode(LED, OUTPUT);
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// setup ADC
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ADMUX = 0x60; // left adjust, adc0, internal vcc
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ADCSRA = 0xe5; // turn on adc, ck/32, auto trigger
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ADCSRB = 0x07; // t1 capture for trigger
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DIDR0 = 0x01; // turn off digital inputs for adc0
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// setup PWM
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TCCR1A = (((PWM_QTY - 1) << 5) | 0x80 | (PWM_MODE << 1)); //
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TCCR1B = ((PWM_MODE << 3) | 0x11); // ck/1
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TIMSK1 = 0x20; // interrupt on capture interrupt
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ICR1H = (PWM_FREQ >> 8);
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ICR1L = (PWM_FREQ & 0xff);
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DDRB |= ((PWM_QTY << 1) | 0x02); // turn on outputs
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sei(); // turn on interrupts - not really necessary with arduino
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}
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void loop() {
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// nothing happens here, all down in the interrupt
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}
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void checkButton()
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{
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counter2++; //to save resources, the pushbuttons are checked every 2000 times.
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if(counter2==2000)
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{
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counter2=0;
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if (!digitalRead(PUSHBUTTON_1)) {
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if (counter > B_MIN) counter-=1; // if not at min, decrement
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}
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if (!digitalRead(PUSHBUTTON_2)) {
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if (counter < B_MAX) counter+=1; // if not at max, increment
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}
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}
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}
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ISR(TIMER1_CAPT_vect) { // all processing happens here
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// output the last value calculated
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OCR1AL = ((data_buffer + 0x8000) >> 8); // convert to unsigned, send out high byte
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OCR1BL = data_buffer; // send out low byte
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// get ADC data
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byte temp1 = ADCL; // you need to fetch the low byte first
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byte temp2 = ADCH; // yes it needs to be done this way
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int input = ((temp2 << 8) | temp1) + 0x8000; // make a signed 16b value
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checkButton();
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// Delay_Depth=counter;
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sDelayBuffer0[DelayCounter] = input;
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POT0 = counter;
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DelayCounter++;
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if(DelayCounter >= Delay_Depth)
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{
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DelayCounter = 0;
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if(count_up)
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{
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for(p=0;p<POT0+1;p++)
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sDelayBuffer0[Delay_Depth+p]=sDelayBuffer0[Delay_Depth-1];
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Delay_Depth=Delay_Depth+POT0;
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if (Delay_Depth>=MAX_DELAY)count_up=0;
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}
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else
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{
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Delay_Depth=Delay_Depth-POT0;
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if (Delay_Depth<=MIN_DELAY)count_up=1;
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}
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}
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// save value for playback next interrupt
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data_buffer = sDelayBuffer0[DelayCounter];
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}
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