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66 lines
1.0 KiB
Plaintext
66 lines
1.0 KiB
Plaintext
15 years ago
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#include <avr/interrupt.h>
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#include <avr/io.h>
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int pinA = 11;
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int pinB = 12;
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int ledPin = 13;
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void setup() {
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//Timer2 Settings
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TCCR2A = 0;
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TCCR2B = 0<<CS22 | 1<<CS21 | 0<<CS20;
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//Timer2 Overflow Interrupt Enable
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TIMSK2 = 1<<TOIE2;
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// pullups
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digitalWrite(pinA, HIGH);
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digitalWrite(pinB, HIGH);
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Serial.begin(9600);
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}
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volatile int8_t enc_delta; // -128 ... 127
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static int8_t last;
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ISR(TIMER2_OVF_vect) {
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int8_t neu, diff;
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// convert gray to binary
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neu = 0;
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if(digitalRead(pinA))
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neu = 3;
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if(digitalRead(pinB))
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neu ^= 1;
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diff = last - neu; // difference last - new
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if( diff & 1 ) { // bit 0 = value (1)
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last = neu; // store new as next last
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enc_delta += (diff & 2) - 1; // bit 1 = direction (+/-)
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}
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}
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int8_t val_alt;
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void loop() {
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int8_t val;
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digitalWrite(13,HIGH);
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cli();
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val = enc_delta;
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// enc_delta = val & 1;
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sei();
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if (val != val_alt) {
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Serial.println(val>>1);
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}
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val_alt = val;
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delay(100);
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digitalWrite(13,LOW);
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delay(100);
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}
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