// 2009 Kenneth Finnegan
// kennethfinnegan.blogspot.com
 
#include <Wire.h>
#include <LiquidCrystal.h>
 
//// PINS ////
#define LEDPIN  13
LiquidCrystal lcd(2,3,4,5,6,7);
//// I2C ADDRESSES ////
// DS1307 RTC chip
#define RTCI2C  (B1101000)
// DS1631 Temp sensor
#define TEMPI2C  (B1001000)
// AT24C1024B EEPROM
#define EEPROMI2C  (B1010000)
 
// TEMP SENSOR OP CODES
#define STARTTEMP  0x51
#define READTEMP   0xAA
 
byte oldminute, temp[2];
byte second, minute, hour, day, month, year;
unsigned int tempreadcount=0;
 
void updatedata();
void writetemp();
 
void setup() {
  lcd.begin(16,2);
  Wire.begin();
  pinMode(LEDPIN, OUTPUT);
  digitalWrite(LEDPIN, HIGH);
  
  // Make sure the clock has valid data
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x00);
  Wire.endTransmission();
  Wire.requestFrom(RTCI2C, 1);
  byte runningflag = Wire.receive();
  
  // Make sure that at least the clock didn't lose power
  // by checking the CH (Clock Halt) flag
  if (runningflag & (1<<7)) {
    lcd.setCursor(0,0);
    lcd.print("ERROR: RTC DEAD!");
    // We don't want to do anything without valid data
    int ledflag = 1;
    while (1) {
      delay(500);
      digitalWrite(LEDPIN, ledflag = !ledflag);
    }
  }
  
  // Extract the read count from the clock's battery backed
  // SRAM to make sure we don't overwrite data on the EEPROM
  // after power loss.
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x08);
  Wire.endTransmission();
  Wire.requestFrom(RTCI2C, 2);
  tempreadcount = Wire.receive() << 8; // MSB
  tempreadcount += Wire.receive(); // LSB
  lcd.setCursor(0,0);
  lcd.print("READ CNT: 0x");
  lcd.print(tempreadcount, HEX);
  
  // Start the thermostat temp conversions
  Wire.beginTransmission(TEMPI2C);
  Wire.send(STARTTEMP);
  Wire.endTransmission();
  // Wait for first temp conversion to finish (750ms)
  delay(800);
  lcd.clear();
  digitalWrite(LEDPIN, LOW);
  updatedata();
}
 
void loop() {
  oldminute = minute;
  updatedata();
  
  if (oldminute != minute) {
    writetemp();
  }
  delay(100);
}
 
void updatedata() {
  char time[] = "XX:XX:XX";
  char date[] = "XX/XX/XX";
  
  // Update time
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x00);
  Wire.endTransmission();
  Wire.requestFrom(RTCI2C, 7);
  second = Wire.receive() & 0x7f;
  minute = Wire.receive();
  hour   = Wire.receive() & 0x3f;
           Wire.receive(); // ignore day of week
  day    = Wire.receive();
  month  = Wire.receive();
  year   = Wire.receive();
  
  // Update temp
  Wire.beginTransmission(TEMPI2C);
  Wire.send(READTEMP);
  Wire.endTransmission();
  Wire.requestFrom(TEMPI2C, 2);
  temp[0] = Wire.receive(); // MSB
  temp[1] = Wire.receive(); // LSB
  
  time[0] = '0' + (hour >> 4 & 0xf);
  time[1] = '0' + (hour & 0xf);
  time[3] = '0' + (minute >> 4 & 0xf);
  time[4] = '0' + (minute & 0xf);
  time[6] = '0' + (second >> 4);
  time[7] = '0' + (second & 0xf);
  date[0] = '0' + (month >> 4 & 0xf);
  date[1] = '0' + (month & 0xf);
  date[3] = '0' + (day >> 4 & 0xf);
  date[4] = '0' + (day & 0xf);
  date[6] = '0' + (year >> 4 & 0xf);
  date[7] = '0' + (year & 0xf);
  
  lcd.setCursor(4,0);
  lcd.print(time);
  lcd.setCursor(0,1);
  lcd.print(date);
  
  lcd.setCursor(10,1);
  lcd.print(temp[0], DEC);
  lcd.print(".");
  lcd.print(temp[1] / 25, DEC); // fractional degree
  lcd.write(B11011111); // degree symbol
  lcd.print("C");
}
 
void writetemp() {
  digitalWrite(LEDPIN, HIGH);
  long wordaddr = ((long)tempreadcount) * 2;
  // AT24C1024B adds the 17th addr bit to I2C addr
  byte eei2caddr = EEPROMI2C | (wordaddr>>16);
  
  // Write out tempurature to EEPROM
  Wire.beginTransmission(eei2caddr);
  Wire.send((byte)(wordaddr>>8) & 0xFF);
  Wire.send((byte)(wordaddr) & 0xFF);
  Wire.send(temp[0]);
  Wire.send(temp[1]);
  Wire.endTransmission();
 
  // Update read count here and in clock's SRAM
  tempreadcount++;
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x08);
  Wire.send((byte)(tempreadcount>>8) & 0xFF);
  Wire.send((byte)(tempreadcount) & 0xFF);
  Wire.endTransmission();
  
  delay(10);
  digitalWrite(LEDPIN, LOW);
}

// 2009 Kenneth Finnegan
// kennethfinnegan.blogspot.com
// Use this to dump contents of EEPROM to Serial
 
//// NOTE ////
// Some of these commands are still broken. Once 
// I got the D command working, didn't really care
// about the rest...
 
// Commands:
//  Tyymmddhhmmss - set the current date/time
//  t - print current time
//  D - dump the EEPROM
//  Z - Zero out RTC RAM
 
#include <Wire.h>
 
// DS1307 RTC chip
#define RTCI2C  (B1101000)
// AT24C1024B EEPROM
#define EEPROMI2C  (B1010000)
 
#define DECTOBCD(a)  ((a/10)*16 + (a%10))
#define BCDTODEC(a)  ((a/16)*10 + (a%16))
 
unsigned int tempreadcount = 0;
byte second, minute, hour, day, month, year;
 
void dumpdata();
void setdate();
void printdate();
void zeroram();
 
void setup() {
  Wire.begin();
  Serial.begin(9600);
  
  // Make sure the clock has valid data
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x00);
  Wire.endTransmission();
  Wire.requestFrom(RTCI2C, 1);
  byte runningflag = Wire.receive();
  
  // Make sure that at least the clock didn't lose power
  // but checking the CH (Clock Halt) flag
  if (runningflag & (1<<7)) {
    Serial.println("ERROR: RTC DEAD");
    tempreadcount = 0xFFFF;
  } else {
    // Extract the read count from the clock's SRAM
    Wire.beginTransmission(RTCI2C);
    Wire.send(0x08);
    Wire.endTransmission();
    Wire.requestFrom(RTCI2C, 2);
    tempreadcount = Wire.receive() << 8; // MSB
    tempreadcount += Wire.receive(); // LSB
  }
  
  
}
 
void loop() {
  int funccode=0;
  if (Serial.available()) {
    funccode = Serial.read();
    switch(funccode) {
      case 'D': // Dump EEPROM data
        dumpdata();
        break;
      case 'T': // Set the time
        setdate();
      case 't': // Print the time
        printdate();
        break;
      case 'Z': // Zero temp read count
        zeroram();
        break;
    }
  }
}
 
void dumpdata() {
  int i;
  byte temp[2];
  // Clear serial buffer
  while (Serial.available()) {
    Serial.read();
  }
  for (i=0; i<tempreadcount; i++) {
    long wordaddr = ((long)i) * 2;
    // AT24C1024B adds the 17th addr bit to I2C addr
    byte eei2caddr = EEPROMI2C | (wordaddr>>16);
  
    // Read tempurature from EEPROM
    Wire.beginTransmission(eei2caddr);
    Wire.send((byte)(wordaddr>>8) & 0xFF);
    Wire.send((byte)(wordaddr) & 0xFF);
    Wire.endTransmission();
    Wire.requestFrom((int)eei2caddr, (int)0x2);
    temp[0] = Wire.receive();
    temp[1] = Wire.receive();
    
    // Tab seperated for Excel
    Serial.print(i, DEC);
    Serial.print("\t");
    Serial.print(temp[0], DEC);
    Serial.print("\t");
    Serial.println(temp[1], DEC);
    
    //delay(1);
    // Break on any key press
    if (Serial.available()) {
      return;
    }
  }
}
 
void setdate() {
  year = (byte) ((Serial.read()-'0')*10 + (Serial.read()-'0'));
  month = (byte) ((Serial.read()-'0')*10 + (Serial.read()-'0'));
  day = (byte) ((Serial.read()-'0')*10 + (Serial.read()-'0'));
  hour = (byte) ((Serial.read()-'0')*10 + (Serial.read()-'0'));
  minute = (byte) ((Serial.read()-'0')*10 + (Serial.read()-'0'));
  second = (byte) ((Serial.read()-'0')*10 + (Serial.read()-'0'));
  
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x00);
  Wire.send(DECTOBCD(second));
  Wire.send(DECTOBCD(minute));
  Wire.send(DECTOBCD(hour));
  Wire.send(0x1); // ignore day of week (1-7)
  Wire.send(DECTOBCD(day));
  Wire.send(DECTOBCD(month));
  Wire.send(DECTOBCD(year));
  Wire.endTransmission();
}
 
void printdate() {
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x00);
  Wire.endTransmission();
  Wire.requestFrom(RTCI2C, 7);
  second = BCDTODEC(Wire.receive() & 0x7F);
  minute = BCDTODEC(Wire.receive());
  hour = BCDTODEC(Wire.receive() & 0x3F);
  Wire.receive(); // ignore day of week (1-7)
  day = BCDTODEC(Wire.receive());
  month = BCDTODEC(Wire.receive());
  year = BCDTODEC(Wire.receive());
  
  Serial.print(hour, DEC);
  Serial.print(":");
  Serial.print(minute, DEC);
  Serial.print(":");
  Serial.print(second, DEC);
  Serial.print("  ");
  Serial.print(month, DEC);
  Serial.print("/");
  Serial.print(day, DEC);
  Serial.print("/");
  Serial.println(year, DEC);
}
 
void zeroram() {
  Serial.println("ZEROING TEMP READ COUNT IN RTC RAM");
  Wire.beginTransmission(RTCI2C);
  Wire.send(0x08);
  Wire.send(0x00);
  Wire.send(0x00);
  Wire.endTransmission();
}