encoders.cpp

// encoders.cpp
/*
This file is part of AYAB.

    AYAB is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    AYAB is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with AYAB.  If not, see <http://www.gnu.org/licenses/>.

    Copyright 2013-2015 Christian Obersteiner, Andreas Müller
    http://ayab-knitting.com
*/

#include "Arduino.h"
#include "./encoders.h"


Encoders::Encoders() {
  m_direction    = NoDirection;
  m_hallActive   = NoDirection;
  m_beltShift    = Unknown;
  m_carriage     = NoCarriage;
  m_encoderPos   = 0x00;
}


void Encoders::encA_interrupt() {
  m_hallActive = NoDirection;

  static bool _oldState = false;
  bool _curState = digitalRead(ENC_PIN_A);

  if (!_oldState && _curState) {
    encA_rising();
  } else if (_oldState && !_curState) {
    encA_falling();
  }
  _oldState = _curState;
}

/*
 * PRIVATE METHODS
 */ 
void Encoders::encA_rising() {
  // Direction only decided on rising edge of encoder A
  m_direction = digitalRead(ENC_PIN_B) ? Right : Left;

  // Update carriage position
  if (Right == m_direction) {
    if (m_encoderPos < END_RIGHT) {
      m_encoderPos++;
    }
  }

  // In front of Left Hall Sensor?
  uint16 hallValue = analogRead(EOL_PIN_L);
  if (hallValue < FILTER_L_MIN
     || hallValue > FILTER_L_MAX) {
    m_hallActive = Left;

    // TODO(chris): Verify these decisions!
    if (hallValue < FILTER_L_MIN) {
      if (m_carriage == K /*&& m_encoderPos == ?? */) {
        m_carriage = G;
      } else {
        m_carriage = L;
      }
    } else if (hallValue > FILTER_L_MAX) {
      m_carriage = K;
    }

    // Belt shift signal only decided in front of hall sensor
    m_beltShift = digitalRead(ENC_PIN_C) ? Regular : Shifted;

    // Known position of the carriage -> overwrite position
    m_encoderPos = END_LEFT + 28;
  }
}


void Encoders::encA_falling() {
  // Update carriage position
  if (Left == m_direction) {
    if (m_encoderPos > END_LEFT) {
        m_encoderPos--;
    }
  }

  // In front of Right Hall Sensor?
  uint16 hallValue = analogRead(EOL_PIN_R);
  if (hallValue < FILTER_R_MIN
      || hallValue > FILTER_R_MAX) {
    m_hallActive = Right;

    if (hallValue < FILTER_R_MIN) {
      m_carriage = K;
    }

    // Belt shift signal only decided in front of hall sensor
    m_beltShift = digitalRead(ENC_PIN_C) ? Shifted : Regular;

    // Known position of the carriage -> overwrite position
    m_encoderPos = END_RIGHT - 28;
  }
}

byte Encoders::getPosition() {
  return m_encoderPos;
}

Beltshift_t Encoders::getBeltshift() {
  return m_beltShift;
}

Direction_t Encoders::getDirection() {
  return m_direction;
}

Direction_t Encoders::getHallActive() {
  return m_hallActive;
}

Carriage_t Encoders::getCarriage() {
  return m_carriage;
}

uint16 Encoders::getHallValue(Direction_t pSensor) {
  switch (pSensor) {
    case Left:
      return analogRead(EOL_PIN_L);
    case Right:
      return analogRead(EOL_PIN_R);
    default:
      return 0;
  }
}