Rotary Encoder

Exemplo de como usar um "Rotary Encoder" com o Arduino:

Esquema geral de ligação ao Arduino:

Existem vários exemplos na Web, o que escolhi e testei foi este:

//http://www.circuitsathome.com/mcu/reading-rotary-encoder-on-arduino

/* Rotary encoder read example */

#define ENC_A 14

#define ENC_B 15

#define ENC_PORT PINC

void setup()

{

  /* Setup encoder pins as inputs */

  pinMode(ENC_A, INPUT);

  digitalWrite(ENC_A, HIGH);

  pinMode(ENC_B, INPUT);

  digitalWrite(ENC_B, HIGH);

  Serial.begin (115200);

  Serial.println("Start");

}

void loop()

{

 static uint8_t counter = 0;      //this variable will be changed by encoder input

 int8_t tmpdata;

 /**/

  tmpdata = read_encoder();

  if( tmpdata ) {

    Serial.print("Counter value: ");

    Serial.println(counter, DEC);

    counter += tmpdata;

    if( counter == 22 ) {

Serial.println("BINGO");}

  }

}

/* returns change in encoder state (-1,0,1) */

int8_t read_encoder()

{

  int8_t enc_states[] = {0,-1,1,0,1,0,0,-1,-1,0,0,1,0,1,-1,0};

  static uint8_t old_AB = 0;

  /**/

  old_AB <<= 2;                   //remember previous state

  old_AB |= ( ENC_PORT & 0x03 );  //add current state

  return ( enc_states[( old_AB & 0x0f )]);

}