/*
 * Copyright (c) 2009 John L. Scarfone
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    - Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    - Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <Peggy2.h>

/***  DS1620 connections
D0 -> DQ(1)  (via 330 resistor)
D1 -> CLK(2)
C5 -> !RST(3)
***/

const uint8_t START_CONV = 0xee;
const uint8_t READ_TEMP = 0xaa;
const uint8_t READ_CONF = 0xac;
const uint8_t READ_CTR = 0xa0;
const uint8_t READ_SLOPE = 0xa9;  /* this is documented but doesn't work on my chip */
const uint8_t LOAD_SLOPE = 0x41;  /* this is undocumented but works on my chip, apparently there are at least two DS1620s */

/* data for digits 0-9 */
long numbers[] =
{
  0x699996,
  0xe44464,
  0xf12496,
  0x698496,
  0x88e999,
  0x69871f,
  0x69971e,
  0x22248f,
  0x699696,
  0x78e996
};

Peggy2 frame;
float minTemp = 99.9;
float maxTemp = 0.;
float lastTemp = 0;
float lastTemp5Minute = 0;
float lastTemp20Minute = 0;
float lastTemp60Minute = 0;
int count = 0;

void setup()
{
  frame.HardwareInit();
  frame.Clear();

  DDRC |= _BV(5);  /* C5 output */
  rstLow();        /* excommunicate DS1620 */
}

void loop()
{
  float temp;
 
  if (getTemp(&temp))
  {
    if (temp > maxTemp)
      maxTemp = temp;
    if (temp < minTemp)
      minTemp = temp;
 
    printTemp(temp, 0);
    printTemp(minTemp, 7);
    printTemp(maxTemp, 14);
    printTempDiff(temp);
    lastTemp = temp;
    if (count % 60 == 0)
    {
      printTempDiff5Minute(temp);
      lastTemp5Minute = temp;
    }
    if (count % 240 == 0)
    {
      printTempDiff20Minute(temp);
      lastTemp20Minute = temp;
    }
    if (count % 720 == 0)
    {
      printTempDiff60Minute(temp);
      lastTemp60Minute = temp;
      count = 0;
    }
  }
  else
  {
    printNoTemp(0);
    printTemp(minTemp, 7);
    printTemp(maxTemp, 14);
  }  
  frame.RefreshAll(5575);
  ++count;
}

/****/

void printNum(uint8_t num, uint8_t x, uint8_t y)
{
  uint8_t i, j;
  long bPos;
  long numVal;
 
  numVal = numbers[num];
  bPos = 1;
  for (i=0; i<6; ++i)
    for (j=0; j<4; ++j)
    {
      if (numVal & bPos)
        frame.SetPoint(x+j, y+i);
      else
        frame.ClearPoint(x+j, y+i);
      bPos <<= 1;
    }
}

void clearNum(uint8_t x, uint8_t y)
{
  uint8_t i, j;
 
  for (i=0; i<6; ++i)
    for (j=0; j<4; ++j)
      frame.ClearPoint(x+j, y+i);
}

void printDash(uint8_t x, uint8_t y)
{
  uint8_t i, j;
 
  for (i=0; i<2; ++i)
    for (j=0; j<4; ++j)
      frame.ClearPoint(x+j, y+i);
  for (j=0; j<4; ++j)
    frame.SetPoint(x+j, y+2);
  for (i=3; i<6; ++i)
    for (j=0; j<4; ++j)
      frame.ClearPoint(x+j, y+i);
}

void printTemp(float temp, uint8_t y)
{
  int iTemp;
  uint8_t digit;

  frame.SetPoint(10, 5+y);

  if (temp >= 100)
    temp = 99.9;
  else if (temp <= 0)
    temp = 0.;

  iTemp = round(temp*10);

  digit = iTemp % 10;
  iTemp /= 10;
  printNum(digit, 12, y);

  digit = iTemp % 10;
  iTemp /= 10;
  printNum(digit, 5, y);

  digit = iTemp % 10;
  if (digit == 0)
    clearNum(0, y);
  else
    printNum(digit, 0, y);
}

void printNoTemp(uint8_t y)
{
  frame.SetPoint(10, 5+y);
  printDash(0, y);
  printDash(5, y);
  printDash(12, y);
}

void printTempDiff(float temp)
{
  int barLength, i;

  if (lastTemp == 0)
    return;

  for (i=0; i<25; ++i)
    frame.ClearPoint(18, i);
  for (i=17; i<25; ++i)
    frame.SetPoint(i, 12);

  barLength = round((temp - lastTemp) / .01);
  if (barLength > 0)
  {
    if (barLength > 12)
      barLength = 12;
    for (i=0; i<barLength; ++i)
      frame.SetPoint(18, 11-i);
  }
  else
  {
    if (barLength < -12)
      barLength = -12;
    for (i=0; i>barLength; --i)
      frame.SetPoint(18, 13-i);
  }
}

void printTempDiff5Minute(float temp)
{
  int barLength, i;

  if (lastTemp5Minute == 0)
    return;

  for (i=0; i<25; ++i)
    frame.ClearPoint(20, i);
  frame.SetPoint(20, 12);

  barLength = round((temp - lastTemp5Minute) / .1);
  if (barLength > 0)
  {
    if (barLength > 12)
      barLength = 12;
    for (i=0; i<barLength; ++i)
      frame.SetPoint(20, 11-i);
  }
  else
  {
    if (barLength < -12)
      barLength = -12;
    for (i=0; i>barLength; --i)
      frame.SetPoint(20, 13-i);
  }
}

void printTempDiff20Minute(float temp)
{
  int barLength, i;

  if (lastTemp20Minute == 0)
    return;

  for (i=0; i<25; ++i)
    frame.ClearPoint(22, i);
  frame.SetPoint(22, 12);

  barLength = round((temp - lastTemp20Minute) / .25);
  if (barLength > 0)
  {
    if (barLength > 12)
      barLength = 12;
    for (i=0; i<barLength; ++i)
      frame.SetPoint(22, 11-i);
  }
  else
  {
    if (barLength < -12)
      barLength = -12;
    for (i=0; i>barLength; --i)
      frame.SetPoint(22, 13-i);
  }
}

void printTempDiff60Minute(float temp)
{
  int barLength, i;

  if (lastTemp60Minute == 0)
    return;

  for (i=0; i<25; ++i)
    frame.ClearPoint(24, i);
  frame.SetPoint(24, 12);

  barLength = round((temp - lastTemp60Minute) / .5);
  if (barLength > 0)
  {
    if (barLength > 12)
      barLength = 12;
    for (i=0; i<barLength; ++i)
      frame.SetPoint(24, 11-i);
  }
  else
  {
    if (barLength < -12)
      barLength = -12;
    for (i=0; i>barLength; --i)
      frame.SetPoint(24, 13-i);
  }
}

/** DS1620 routines **/

boolean getTemp(float *temp)
{
  uint8_t i;
  int data, ctr, cntPerC;

  frame.SetPoint(24, 0);
 
  clkHigh();
  rstHigh();
  write8Bit(START_CONV);
  rstLow();

  /* the DS1620 takes some time to finish the conversion so
     update the display while we're waiting */
  frame.RefreshAll(250);
  for (i=0; i<5; ++i)
  {
    /* check status */
    clkHigh();
    rstHigh();
    write8Bit(READ_CONF);
    if (read8Bit() & 0x80)
    {
      /* ready to read temp */
      rstLow();
      break;
    }
    /* still not ready */
    rstLow();
    frame.RefreshAll(250);
  }

  if (i == 5)
  {
    frame.ClearPoint(24, 0);
    return false;
  }

  frame.RefreshAll(10);
 
  /* read temp */
  clkHigh();
  rstHigh();
  write8Bit(READ_TEMP);
  data = read9Bit();
  rstLow();

  frame.RefreshAll(10);
 
  /* read counter */
  clkHigh();
  rstHigh();
  write8Bit(READ_CTR);
  ctr = read9Bit();
  rstLow();
 
  frame.RefreshAll(10);

  /* load slope */
  clkHigh();
  rstHigh();
  write8Bit(LOAD_SLOPE);
  rstLow();
 
  frame.RefreshAll(10);

  /* read counter */
  clkHigh();
  rstHigh();
  write8Bit(READ_CTR);
  cntPerC = read9Bit();
  rstLow();

  frame.RefreshAll(10);

  data >>= 1;  /* strip last bit and divide by two */
  if (data & 0x80)  /* neg, need to sign extend */
    data |= ~0xff;
  *temp = (float)data - .25 + (cntPerC - ctr)/(float)cntPerC;
  *temp = *temp * 9. / 5. + 32.;
  frame.ClearPoint(24, 0);
  return true;
}

void write8Bit(uint8_t data)
{
  uint8_t i;
 
  for (i=0; i<8; ++i)
  {
    outBit(data & 1);
    data >>= 1;
  }
}

uint8_t read8Bit(void)
{
  uint8_t data = 0;
  uint8_t i, bit;
 
  DDRD &= 0xfe;  /* D0 input */
  PORTD &= 0xfe;

  for (i=0; i<8; ++i)
  {
    clkLow();
    bit = PIND & 0x01;
    clkHigh();
    data |= bit << i;
  }

  DDRD |= 0x01;  /* D0 output */

  return data;
}

int read9Bit(void)
{
  int data = 0;
  uint8_t i, bit;
 
  DDRD &= 0xfe;  /* D0 input */
  PORTD &= 0xfe;

  for (i=0; i<9; ++i)
  {
    clkLow();
    bit = PIND & 0x01;
    clkHigh();
    data |= bit << i;
  }

  DDRD |= 0x01;  /* D0 output */

  return data;
}

void outBit(uint8_t bit)
{
  if (bit)
    PORTD |= 0x01;
  else
    PORTD &= 0xfe;
  clkLow();
  clkHigh();
}

void clkHigh()
{
  PORTD |= 0x02;
  delayMicroseconds(1);
}

void clkLow()
{
  PORTD &= 0xfd;
  delayMicroseconds(1);
}

void rstHigh()
{
  PORTC |= 0x20;
  delayMicroseconds(1);
}

void rstLow()
{
  PORTC &= 0xdf;
  delayMicroseconds(1);
}