Arduino - Plant Watering System with TFT LCD

//Author Danny van den brande.

#include "DHT.h"
#include <SPFD5408_Adafruit_GFX.h>    // Core graphics library
#include <SPFD5408_Adafruit_TFTLCD.h> // Hardware-specific library
#include <SPFD5408_TouchScreen.h>
//                                    BEGIN CLOCK
#include <DS1302RTC.h>//clock module DS1302
#include <Time.h>//Need for clock module
#define DS1302_SCLK_PIN   21    // Arduino pin for the Serial Clock
//PIN 21 (SCLK_PIN) = CLK on CLOCK and SCL on arduino 
#define DS1302_IO_PIN     20    // Arduino pin for the Data I/O
//PIN 20 (IO_PIN) = DAT on CLOCK and SDA on arduino 
#define DS1302_CE_PIN     19    // Arduino pin for the Chip Enable
//PIN 19 (CE_PIN) = RST on CLOCK and TX1 on arduino for this you can define any free Digital pin.
#define bcd2bin(h,l)    (((h)*10) + (l))
#define bin2bcd_h(x)   ((x)/10)
#define bin2bcd_l(x)    ((x)%10)

#define DS1302_SECONDS           0x80
#define DS1302_MINUTES           0x82
#define DS1302_HOURS             0x84
#define DS1302_DATE              0x86
#define DS1302_MONTH             0x88
#define DS1302_DAY               0x8A
#define DS1302_YEAR              0x8C
#define DS1302_ENABLE            0x8E
#define DS1302_TRICKLE           0x90
#define DS1302_CLOCK_BURST       0xBE
#define DS1302_CLOCK_BURST_WRITE 0xBE
#define DS1302_CLOCK_BURST_READ  0xBF
#define DS1302_RAMSTART          0xC0
#define DS1302_RAMEND            0xFC
#define DS1302_RAM_BURST         0xFE
#define DS1302_RAM_BURST_WRITE   0xFE
#define DS1302_RAM_BURST_READ    0xFF
#define DS1302_D0 0
#define DS1302_D1 1
#define DS1302_D2 2
#define DS1302_D3 3
#define DS1302_D4 4
#define DS1302_D5 5
#define DS1302_D6 6
#define DS1302_D7 7
#define DS1302_READBIT DS1302_D0 // READBIT=1: read instruction
// Bit for clock (0) or ram (1) area, 
// called R/C-bit (bit in address)
#define DS1302_RC DS1302_D6

// Seconds Register
#define DS1302_CH DS1302_D7   // 1 = Clock Halt, 0 = start

// Hour Register
#define DS1302_AM_PM DS1302_D5 // 0 = AM, 1 = PM
#define DS1302_12_24 DS1302_D7 // 0 = 24 hour, 1 = 12 hour

// Enable Register
#define DS1302_WP DS1302_D7   // 1 = Write Protect, 0 = enabled

#define DS1302_ROUT0 DS1302_D0
#define DS1302_ROUT1 DS1302_D1
#define DS1302_DS0   DS1302_D2
#define DS1302_DS1   DS1302_D2
#define DS1302_TCS0  DS1302_D4
#define DS1302_TCS1  DS1302_D5
#define DS1302_TCS2  DS1302_D6
#define DS1302_TCS3  DS1302_D7



// Bit for reading (bit in address)
#define DS1302_READBIT DS1302_D0 // READBIT=1: read instruction

#define DHTPIN 16     // what pin we're connected to
#define DHTTYPE DHT11 // DHT 11
#define DS1302_READBIT DS1302_D0 // READBIT=1: read instruction
#define LCD_CS A3 // Chip Select goes to Analog 3
#define LCD_CD A2 // Command/Data goes to Analog 2
#define LCD_WR A1 // LCD Write goes to Analog 1
#define LCD_RD A0 // LCD Read goes to Analog 0

#define LCD_RESET A4 // Can alternately just connect to Arduino's reset pin

// Assign human-readable names to some common 16-bit color values:
#define BLACK   0x0000
#define BLUE    0x001F
#define RED     0xF800
#define GREEN   0x07E0
#define CYAN    0x07FF
#define MAGENTA 0xF81F
#define YELLOW  0xFFE0
#define WHITE   0xFFFF

// OBJECTS LCD ET DHT

Adafruit_TFTLCD tft(LCD_CS, LCD_CD, LCD_WR, LCD_RD, LCD_RESET);

DHT dht(DHTPIN, DHTTYPE);

float hprev, tprev, hicprev;
int moisture = 0;
int moisture1 = 0;
int moisture2 = 0;
int moisture3 = 0;
int moisture4 = 0;
int moisture5 = 0;
int sensorValue1;
int sensorValue2;
int sensorValue3;
int sensorValue4;
int sensorValue5;
int sensorValue;

int relay = 35;
int relay1 = 36;
int relay2 = 37;
int relay3 = 38;
int relay4 = 39;
int relay5 = 40;
// Structure for the first 8 registers.
// These 8 bytes can be read at once with 
// the 'clock burst' command.
// Note that this structure contains an anonymous union.
// It might cause a problem on other compilers.
typedef struct ds1302_struct
{
  uint8_t Seconds:4;      // low decimal digit 0-9
  uint8_t Seconds10:3;    // high decimal digit 0-5
  uint8_t CH:1;           // CH = Clock Halt
  uint8_t Minutes:4;
  uint8_t Minutes10:3;
  uint8_t reserved1:1;
  union
  {
    struct
    {
      uint8_t Hour:4;
      uint8_t Hour10:2;
      uint8_t reserved2:1;
      uint8_t hour_12_24:1; // 0 for 24 hour format
    } h24;
    struct
    {
      uint8_t Hour:4;
      uint8_t Hour01:1;
      uint8_t AM_PM:1;      // 0 for AM, 1 for PM
      uint8_t reserved2:1;
      uint8_t hour_12_24:1; // 1 for 12 hour format
    } h12;
  };
  uint8_t Date:4;           // Day of month, 1 = first day
  uint8_t Date10:2;
  uint8_t reserved3:2;
  uint8_t Month:4;          // Month, 1 = January
  uint8_t Month10:1;
  uint8_t reserved4:3;
  uint8_t Day:3;            // Day of week, 1 = first day (any day)
  uint8_t reserved5:5;
  uint8_t Year:4;           // Year, 0 = year 2000
  uint8_t Year10:4;
  uint8_t reserved6:7;
  uint8_t WP:1;             // WP = Write Protect
};



void setup() 
{
  ds1302_struct rtc;
  
  Serial.begin(9600);
//  Serial.println(F("BLUECORE TECH"));
  pinMode (relay, OUTPUT);
  pinMode (relay1, OUTPUT);
  pinMode (relay2, OUTPUT);
  pinMode (relay3, OUTPUT);
  pinMode (relay4, OUTPUT);
  pinMode (relay5, OUTPUT);
//  digitalWrite (relay, HIGH); 
  

#ifdef USE_ADAFRUIT_SHIELD_PINOUT
//  Serial.println(F("Using Adafruit 2.8\" TFT Arduino Shield Pinout"));
#else
//  Serial.println(F("Using Adafruit 2.8\" TFT Breakout Board Pinout"));
#endif

//  Serial.print("TFT size is "); Serial.print(tft.width()); Serial.print("x"); Serial.println(tft.height());

  //tft.reset();

  uint16_t identifier = tft.readID();

  if(identifier == 0x9325) {
//    Serial.println(F("Found ILI9325 LCD driver"));
  } else if(identifier == 0x9327) {
//    Serial.println(F("Found ILI9327 LCD driver"));
  } else if(identifier == 0x9328) {
//    Serial.println(F("Found ILI9328 LCD driver"));
  } else if(identifier == 0x7575) {
//    Serial.println(F("Found HX8347G LCD driver"));
  } else if(identifier == 0x9341) {
//    Serial.println(F("Found ILI9341 LCD driver"));
  } else if(identifier == 0x8357) {
//    Serial.println(F("Found HX8357D LCD driver"));
  } else if(identifier == 0x0154) {
//    Serial.println(F("Found S6D0154 LCD driver"));
  }
  
  tft.begin(identifier);

  iniText();
  
  dht.begin();
//CLOCK MODULE START
    // Start by clearing the Write Protect bit
  // Otherwise the clock data cannot be written
  // The whole register is written, 
  // but the WP-bit is the only bit in that register.
  DS1302_write (DS1302_ENABLE, 0);

  // Disable Trickle Charger.
  DS1302_write (DS1302_TRICKLE, 0x00);

  // Remove the next define, 
// after the right date and time are set.
//  #define SET_DATE_TIME_JUST_ONCE //<comment when time is set, de-comment for setting time once.
  #ifdef SET_DATE_TIME_JUST_ONCE    
   // Fill these variables with the date and time.
  int seconds, minutes, hours, dayofweek, dayofmonth, month, year;

  // Example for april 15, 2013, 10:08, monday is 2nd day of Week.
  // Set your own time and date in these variables.
  seconds    = 0;
  minutes    = 41;
  hours      = 23;
  dayofweek  = 6;  // Day of week, any day can be first, counts 1...7
  dayofmonth = 27; // Day of month, 1...31
  month      = 2;  // month 1...12
  year       = 2016;

  // Set a time and date
  // This also clears the CH (Clock Halt) bit, 
  // to start the clock.

  // Fill the structure with zeros to make 
  // any unused bits zero
  memset ((char *) &rtc, 0, sizeof(rtc));

  rtc.Seconds    = bin2bcd_l( seconds);
  rtc.Seconds10  = bin2bcd_h( seconds);
  rtc.CH         = 0;      // 1 for Clock Halt, 0 to run;
  rtc.Minutes    = bin2bcd_l( minutes);
  rtc.Minutes10  = bin2bcd_h( minutes);
  // To use the 12 hour format,
  // use it like these four lines:
  //    rtc.h12.Hour   = bin2bcd_l( hours);
  //    rtc.h12.Hour10 = bin2bcd_h( hours);
  //    rtc.h12.AM_PM  = 0;     // AM = 0
  //    rtc.h12.hour_12_24 = 1; // 1 for 12 hour format
  rtc.h24.Hour   = bin2bcd_l( hours);
  rtc.h24.Hour10 = bin2bcd_h( hours);
  rtc.h24.hour_12_24 = 0; // 0 for 24 hour format
  rtc.Date       = bin2bcd_l( dayofmonth);
  rtc.Date10     = bin2bcd_h( dayofmonth);
  rtc.Month      = bin2bcd_l( month);
  rtc.Month10    = bin2bcd_h( month);
  rtc.Day        = dayofweek;
  rtc.Year       = bin2bcd_l( year - 2000);
  rtc.Year10     = bin2bcd_h( year - 2000);
  rtc.WP = 0;  

  // Write all clock data at once (burst mode).
  DS1302_clock_burst_write( (uint8_t *) &rtc);
#endif
//              CLOCK MODULE END
}

void loop() 
{
  int sensorValue = analogRead(A15);
  int sensorValue1 = analogRead(A14);
  int sensorValue2 = analogRead(A13);
  int sensorValue3 = analogRead(A12);
  int sensorValue4 = analogRead(A11);
  int sensorValue5 = analogRead(A10);
  sensorValue = constrain (sensorValue, 300,1023);
//  sensorValue1 = constrain (sensorValue1, 300,1023);
//  sensorValue2 = constrain (sensorValue2, 300,1023);
//  sensorValue3 = constrain (sensorValue3, 300,1023);
//  sensorValue4 = constrain (sensorValue4, 300,1023);
//  sensorValue5 = constrain (sensorValue5, 300,1023);
  
  moisture = map (sensorValue, 300, 1023, 100, 0);
  moisture1 = map (sensorValue1, 300, 1023, 100, 0);
  moisture2 = map (sensorValue2, 300, 1023, 100, 0);
  moisture3 = map (sensorValue3, 300, 1023, 100, 0);
  moisture4 = map (sensorValue4, 300, 1023, 100, 0);
  moisture5 = map (sensorValue5, 300, 1023, 100, 0);
//  Serial.println("DHT11 en Soil moisture");
//
  // Wait a few seconds between measurements.


  
  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  // Read temperature as Fahrenheit (isFahrenheit = true)
  float f = dht.readTemperature(true);
  
  // Check if any reads failed and exit early (to try again).
  if (isnan(h) || isnan(t) || isnan(f)) {
//    Serial.println("Communicatie fout met de sensor");
    return;
  }
  // Compute heat index in Fahrenheit (the default)
  float hif = dht.computeHeatIndex(f, h);
  // Compute heat index in Celsius (isFahreheit = false)
  float hic = dht.computeHeatIndex(t, h, false);

  tft.setTextSize(3); 
  tft.setTextColor(GREEN);
  sensorValue = analogRead(A15);
  sensorValue1 = analogRead(A14);
  sensorValue2 = analogRead(A13);
  sensorValue3 = analogRead(A12);
  sensorValue4 = analogRead(A11);
  sensorValue5 = analogRead(A10);

  if (sensorValue) {
  tft.setCursor(35,60);
  tft.setTextSize(2);
  tft.println ("BODEM VOCHT % MONITOR");  << YOUR Text to display
  tft.setCursor(98, 90);
  tft.setTextColor(GREEN);
  tft.fillRect(93,80,67,35,BLACK); 
  tft.println (moisture/1.01);
    if (sensorValue >= 300)
  digitalWrite (relay, HIGH); //TURN ON/OFF OFF RELAY 0 for watering pump
  else
  digitalWrite (relay, LOW);  
  //SENSOR 1 set your sensor here!
  }
 
//             OPTIONAL SENSORS PLACES FOR VALUES ON SCREEN BEGIN
  if (sensorValue) {
  tft.setTextSize(2);
  tft.setCursor(98, 127);
  tft.setTextColor(GREEN);
  tft.fillRect(93,117,67,34,BLACK); 
  tft.println (moisture1/1.01); 
    if (sensorValue1 >= 300)
  digitalWrite (relay1, HIGH); //TURN ON/OFF OFF RELAY 1 for watering pump
  else
  digitalWrite (relay1, LOW);        
  //SENSOR 2 set your sensor here!
  }

  if (sensorValue) {
  tft.setTextSize(2);
  tft.setCursor(98, 164);
  tft.setTextColor(GREEN);
  tft.fillRect(93,154,67,34,BLACK); 
  tft.println (moisture2/1.01);    
    if (sensorValue2 >= 300)
  digitalWrite (relay2, HIGH); //TURN ON/OFF OFF RELAY 2 for watering pump
  else
  digitalWrite (relay2, LOW);          
  //SENSOR 3 set your sensor here!

  }                   // BEGIN SECTION 2 - right section

  if (sensorValue) {
  tft.setCursor(10,60);
  tft.setTextSize(2);
  //tft.println ("BODEM VOCHT%");
  tft.setCursor(256, 90);
  tft.setTextColor(GREEN);
  tft.fillRect(250,80,67,34,BLACK); 
  tft.println (moisture3/1.01);
      if (sensorValue3 >= 300)
  digitalWrite (relay3, HIGH); //TURN ON/OFF OFF RELAY 3 for watering pump
  else
  digitalWrite (relay3, LOW);         
  //SENSOR 4 set your sensor here!
  
  }

  if (sensorValue) {
  tft.setCursor(10,60);
  tft.setTextSize(2);
  //tft.println ("BODEM VOCHT%");
  tft.setCursor(256, 127);
  tft.setTextColor(GREEN);
  tft.fillRect(250,117,67,34,BLACK); 
  tft.println (moisture4/1.01);        
      if (sensorValue4 >= 300)
  digitalWrite (relay4, HIGH); //TURN ON/OFF OFF RELAY 4 for watering pump
  else
  digitalWrite (relay4, LOW); 
  //SENSOR 5 set your sensor here!

  }

  if (sensorValue) {
  tft.setCursor(10,60);
  tft.setTextSize(2);
  //tft.println ("BODEM VOCHT%");
  tft.setCursor(256, 164);
  tft.setTextColor(GREEN);
  tft.fillRect(250,154,67,34,BLACK); 
  tft.println (moisture5/1.01); 
      if (sensorValue5 >= 300)
  digitalWrite (relay5, HIGH); //TURN ON/OFF OFF RELAY 5 for watering pump
  else
  digitalWrite (relay5, LOW);         
  //SENSOR 6 set your sensor here!
  
  }
//                         OPTIONAL SENSORS PLACES ON SCREEN END     
  if (hprev != h) {

  tft.setCursor(10, 25);
  tft.setTextSize(3);
  tft.setTextColor(CYAN); 
  tft.fillRect(3,25,103,25,BLACK); 
  tft.print(h);
  hprev = h;  
  } 
  
  if (tprev != t) {

  tft.setCursor(118, 25);
  tft.setTextSize(3);
  tft.setTextColor(RED); 
  tft.fillRect(111,25,101,25,BLACK); 
  tft.print(t);
  tprev = t;  
  } 
  
  if (hicprev != hic) {

  tft.setCursor(225, 25);
  tft.setTextSize(3);
  tft.setTextColor(YELLOW); 
  tft.fillRect(217,25,100,25,BLACK); 
  tft.print(hic);
  hicprev = hic; 
    
  }

    ds1302_struct rtc;
  char buffer[80];     // the code uses 70 characters.

  // Read all clock data at once (burst mode).
  DS1302_clock_burst_read( (uint8_t *) &rtc);

//+++++++++++  BEGIN TEXT CLOCK TEXT+++++++++++
  
  tft.setTextSize(2); 
  tft.setTextColor(GREEN);
  tft.setCursor(13, 220);
  tft.fillRect(3,215,115,25,BLACK);
  sprintf( buffer, "%02d:%02d:%02d ", \
  bcd2bin( rtc.h24.Hour10, rtc.h24.Hour), \
  bcd2bin( rtc.Minutes10, rtc.Minutes), \
  bcd2bin( rtc.Seconds10, rtc.Seconds));
  tft.print(buffer);

  tft.setTextSize(1);
  tft.setTextColor(BLACK);
  tft.setCursor(127, 218);
  tft.fillRect(122,215,195,25,GREEN);
  sprintf(buffer, "%d,%d," \
  "Dag %d van week,%d", \
  bcd2bin( rtc.Date10, rtc.Date), \
  bcd2bin( rtc.Month10, rtc.Month), \
  rtc.Day, \
  2000 + bcd2bin( rtc.Year10, rtc.Year));   
  tft.println( buffer);

  tft.setTextSize(1);
  tft.setTextColor(BLACK);
  tft.setCursor(127, 230);
//  tft.fillRect(122,215,194,25,GREEN);
  sprintf(buffer, "%d,%d," \
  "Day %d of week,%d", \ 
  bcd2bin( rtc.Month10, rtc.Month), \
  bcd2bin( rtc.Date10, rtc.Date), \
  rtc.Day, \
  2000 + bcd2bin( rtc.Year10, rtc.Year));   
  tft.println( buffer);
  
//+++++++++++  EINDE CLOCK +++++++++++
  if(timeStatus() != timeSet) {
    tft.setTextSize(1.5);
    tft.setTextColor(BLACK);
    tft.setCursor(28, 198);///ERROR TEXT need to be coded correctly
    tft.fillRect(3,191,157,19,RED);
    //tft.print(F("CLOCK ERROR: SYNC!"));
//    return micros() - start; 
delay(1000);
  }
   
}

unsigned long iniText() {
//  unsigned long start = micros();
  
  tft.fillScreen(BLACK);
  tft.setRotation(3);
  tft.setTextSize(1); 
  tft.setTextColor(WHITE);
  
  tft.setCursor(15,5);
  tft.println("Vochtigheid %");
  tft.setCursor(119,10);
  tft.println("Temperatuur oC"); 
  tft.setCursor(235,5);
  tft.println("Gevoelstemp"); //Gevoels temperatuur
  tft.setCursor(122,2);
  tft.println ("BlueCore TECH"); //Put your NAME here COMPANY NAME
  tft.setCursor(190,198);
  tft.println ("ArduinoSensors.NL"); //Put your NAME here COMPANY NAME website

//TEXT SENSORS

  tft.setCursor(10,90);
  tft.setTextColor(WHITE);
  tft.println ("SENSOR:1");
  tft.setCursor(10,127);
  tft.println ("SENSOR:2"); 
  tft.setCursor(10,164);
  tft.println ("SENSOR:3");
  tft.setCursor(170,90);
  tft.println ("SENSOR:4");
  tft.setCursor(170,127);
  tft.println ("SENSOR:5");
  tft.setCursor(170,164);
  tft.println ("SENSOR:6");

//  end TEXT SENSORS

//Interface DESIGN BEGIN
  tft.fillRect(0,0,345,1,WHITE); //Top line header white
  tft.fillRect(0,19,345,2,WHITE); //Top line header 2 white
  tft.fillRect(0,20,345,5,BLACK); //Top line header black 
  tft.fillRect(106,0,5,50,WHITE); //center vertical line header left
  tft.fillRect(212,0,5,50,WHITE); //center vertical line header right  
  tft.fillRect(0,50,345,5,WHITE); //bottom line header.
  tft.fillRect(160,78,5,135,WHITE);//center vertical line
  tft.fillRect(317,0,5,240,WHITE);//center vertical line right
  tft.fillRect(0,0,3,240,WHITE);//center vertical line left  
  tft.fillRect(0,210,345,5,WHITE);//BOTTOM LINE Footer
  tft.fillRect(118,215,4,25,WHITE);//BOTTOM LINE Footer2 vertical small
  tft.fillRect(0,210,345,5,WHITE);//BOTTOM LINE Footer
  tft.fillRect(0,78,345,2,WHITE);//top line center screen
  tft.fillRect(0,115,345,2,WHITE);//line 2 center screen
  tft.fillRect(0,152,345,2,WHITE);//line 3 center screen
  tft.fillRect(0,189,345,2,WHITE);//line 4 center screen
//Interface DESIGN END  
//  return micros() - start;
  
}
  
void DS1302_clock_burst_read( uint8_t *p)///BEGIN CLOCK MODULE PART2
{
  int i;

  _DS1302_start();

  // Instead of the address, 
  // the CLOCK_BURST_READ command is issued
  // the I/O-line is released for the data
  _DS1302_togglewrite( DS1302_CLOCK_BURST_READ, true);  

  for( i=0; i<8; i++)
  {
    *p++ = _DS1302_toggleread();
  }
  _DS1302_stop();
}


// --------------------------------------------------------
// DS1302_clock_burst_write
//
// This function writes 8 bytes clock data in burst mode
// to the DS1302.
//
// This function may be called as the first function, 
// also the pinMode is set.
//
void DS1302_clock_burst_write( uint8_t *p)
{
  int i;

  _DS1302_start();

  // Instead of the address, 
  // the CLOCK_BURST_WRITE command is issued.
  // the I/O-line is not released
  _DS1302_togglewrite( DS1302_CLOCK_BURST_WRITE, false);  

  for( i=0; i<8; i++)
  {
    // the I/O-line is not released
    _DS1302_togglewrite( *p++, false);  
  }
  _DS1302_stop();
}


// --------------------------------------------------------
// DS1302_read
//
// This function reads a byte from the DS1302 
// (clock or ram).
//
// The address could be like "0x80" or "0x81", 
// the lowest bit is set anyway.
//
// This function may be called as the first function, 
// also the pinMode is set.
//
uint8_t DS1302_read(int address)
{
  uint8_t data;

  // set lowest bit (read bit) in address
  bitSet( address, DS1302_READBIT);  

  _DS1302_start();
  // the I/O-line is released for the data
  _DS1302_togglewrite( address, true);  
  data = _DS1302_toggleread();
  _DS1302_stop();

  return (data);
}


// --------------------------------------------------------
// DS1302_write
//
// This function writes a byte to the DS1302 (clock or ram).
//
// The address could be like "0x80" or "0x81", 
// the lowest bit is cleared anyway.
//
// This function may be called as the first function, 
// also the pinMode is set.
//
void DS1302_write( int address, uint8_t data)
{
  // clear lowest bit (read bit) in address
  bitClear( address, DS1302_READBIT);   

  _DS1302_start();
  // don't release the I/O-line
  _DS1302_togglewrite( address, false); 
  // don't release the I/O-line
  _DS1302_togglewrite( data, false); 
  _DS1302_stop();  
}


// --------------------------------------------------------
// _DS1302_start
//
// A helper function to setup the start condition.
//
// An 'init' function is not used.
// But now the pinMode is set every time.
// That's not a big deal, and it's valid.
// At startup, the pins of the Arduino are high impedance.
// Since the DS1302 has pull-down resistors, 
// the signals are low (inactive) until the DS1302 is used.
void _DS1302_start( void)
{
  digitalWrite( DS1302_CE_PIN, LOW); // default, not enabled
  pinMode( DS1302_CE_PIN, OUTPUT);  

  digitalWrite( DS1302_SCLK_PIN, LOW); // default, clock low
  pinMode( DS1302_SCLK_PIN, OUTPUT);

  pinMode( DS1302_IO_PIN, OUTPUT);

  digitalWrite( DS1302_CE_PIN, HIGH); // start the session
  delayMicroseconds( 4);           // tCC = 4us
}


// --------------------------------------------------------
// _DS1302_stop
//
// A helper function to finish the communication.
//
void _DS1302_stop(void)
{
  // Set CE low
  digitalWrite( DS1302_CE_PIN, LOW);

  delayMicroseconds( 4);           // tCWH = 4us
}


// --------------------------------------------------------
// _DS1302_toggleread
//
// A helper function for reading a byte with bit toggle
//
// This function assumes that the SCLK is still high.
//
uint8_t _DS1302_toggleread( void)
{
  uint8_t i, data;

  data = 0;
  for( i = 0; i <= 7; i++)
  {
    // Issue a clock pulse for the next databit.
    // If the 'togglewrite' function was used before 
    // this function, the SCLK is already high.
    digitalWrite( DS1302_SCLK_PIN, HIGH);
    delayMicroseconds( 1);

    // Clock down, data is ready after some time.
    digitalWrite( DS1302_SCLK_PIN, LOW);
    delayMicroseconds( 1);        // tCL=1000ns, tCDD=800ns

    // read bit, and set it in place in 'data' variable
    bitWrite( data, i, digitalRead( DS1302_IO_PIN)); 
  }
  return( data);
}


// --------------------------------------------------------
// _DS1302_togglewrite
//
// A helper function for writing a byte with bit toggle
//
// The 'release' parameter is for a read after this write.
// It will release the I/O-line and will keep the SCLK high.
//
void _DS1302_togglewrite( uint8_t data, uint8_t release)
{
  int i;

  for( i = 0; i <= 7; i++)
  { 
    // set a bit of the data on the I/O-line
    digitalWrite( DS1302_IO_PIN, bitRead(data, i));  
    delayMicroseconds( 1);     // tDC = 200ns

    // clock up, data is read by DS1302
    digitalWrite( DS1302_SCLK_PIN, HIGH);     
    delayMicroseconds( 1);     // tCH = 1000ns, tCDH = 800ns

    if( release && i == 7)
    {
      // If this write is followed by a read, 
      // the I/O-line should be released after 
      // the last bit, before the clock line is made low.
      // This is according the datasheet.
      // I have seen other programs that don't release 
      // the I/O-line at this moment,
      // and that could cause a shortcut spike 
      // on the I/O-line.
      pinMode( DS1302_IO_PIN, INPUT);

      // For Arduino 1.0.3, removing the pull-up is no longer needed.
      // Setting the pin as 'INPUT' will already remove the pull-up.
      // digitalWrite (DS1302_IO, LOW); // remove any pull-up  
    }
    else
    {
      digitalWrite( DS1302_SCLK_PIN, LOW);
      delayMicroseconds( 1);       // tCL=1000ns, tCDD=800ns
    }
  }///////////////////////////// END CLOCK MODULE part 2
}