problems with digital clock disply

Using Arduino Programming Questions
1

Hello all

I am rebuilding my saltwater aquarium system controlled by an arduino after a move to a new home.

During the move i lost the flash drive i had my working sketch stored on.Now i am trying to rebuild the sketch from what files i can find on the internet that i used to get it working.Right now i am working on the lcd display of time and date.

The sketch i used is from the time library i have inserted the name of the system "The Coleman Reef" in the first row of the LCD, "Time" followed by the numeric display of the current time on the second row of the LCD, and "Date" followed by the numeric display of the current date on the third row of the LCD. These items all display correctly on the LCD except for the inclusion of
: then the minute of the hour when the TimeRTCSet sketch was uploaded:
on the first line after the aquarium name.

This is what displays
The Coleman Reef:42:

and :the current minute after the current date on the third line

This is what displays
Date 8/27/2016:the current minute:

I have looked for my mistake but have yet to find it if someone has the time to look at the sketch i am using and give me a hint to what and where i need to look to cure this problem it would be greatly appreciated.

Below is the sketch code

 /*
 * TimeRTCSet.pde
 * example code illustrating Time library with Real Time Clock.
 *
 * RTC clock is set in response to serial port time message 
 * A Processing example sketch to set the time is inclided in the download
 */

#include <Time.h>  
#include <Wire.h>  
#include <DS1307RTC.h>  // a basic DS1307 library that returns time as a time_t
#include <LiquidCrystal_I2C.h>

//LCD definitions
LiquidCrystal_I2C lcd(0x20, 4, 5, 6, 0, 1, 2, 3, 7, NEGATIVE); // 20x4 character lcd settings.

void setup()  {
  Serial.begin(9600);
  setSyncProvider(RTC.get);   // the function to get the time from the RTC
  if(timeStatus()!= timeSet) 
     Serial.println("Unable to sync with the RTC");
  else
     Serial.println("RTC has set the system time");
     
 lcd.begin(20,4);   
    lcd.setCursor(0,0);
    lcd.print("The Coleman Reef");
     
}

void loop()
{
  if(Serial.available())
  {
     time_t t = processSyncMessage();
     if(t >0)
     {
        RTC.set(t);   // set the RTC and the system time to the received value
        setTime(t);          
     }
  }
   digitalClockDisplay();  
   delay(1000);
}

void digitalClockDisplay(){
  // digital clock display of the time
  Serial.print(hour());
  printDigits(minute());
  printDigits(second());
  Serial.print(" ");
  Serial.print(day());
  Serial.print(" ");
  Serial.print(month());
  Serial.print(" ");
  Serial.print(year()); 
  Serial.println();
 
  lcd.setCursor(0,1);
  lcd.print("Time");
  lcd.print(" ");
  lcd.print(hour());
  printDigits(minute());
  printDigits(second());


  lcd.setCursor(0,2);
  lcd.print("Date");
  lcd.print(" ");
  lcd.print(month());
  lcd.print(" /");
  lcd.print(day());
  lcd.print("/ ");
  lcd.print(year()); 
 
}

void printDigits(int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  Serial.print(":");
  if(digits < 10)
    Serial.print('0');
  Serial.print(digits);
  
   lcd.print(":");
  if(digits < 10)
    lcd.print('0');
  lcd.print(digits);
}

/*  code to process time sync messages from the serial port   */
#define TIME_MSG_LEN  11   // time sync to PC is HEADER followed by unix time_t as ten ascii digits
#define TIME_HEADER  'T'   // Header tag for serial time sync message

time_t processSyncMessage() {
  // return the time if a valid sync message is received on the serial port.
  while(Serial.available() >=  TIME_MSG_LEN ){  // time message consists of a header and ten ascii digits
    char c = Serial.read() ; 
    Serial.print(c);  
    if( c == TIME_HEADER ) {       
      time_t pctime = 0;
      for(int i=0; i < TIME_MSG_LEN -1; i++){   
        c = Serial.read();          
        if( c >= '0' && c <= '9'){   
          pctime = (10 * pctime) + (c - '0') ; // convert digits to a number    
        }
      }   
      return pctime; 
    }  
  }
  return 0;
}

Thanks for any help
James

2

Get rid of all the Serial.print() stuff. At this point, you don't need it: you already have the LCD display for output, and the Serial.print() just makes your code more complex.
Once you've done that, I think it will be clear where the problem is. If it still isn't clear, read carefully the part of your code where you output the date and time.

3

What can be useful is to write your output functions to work on any Print class device so things don't get all wonky and messy.
So you specify where you want the output to go rather than hard coding it in the function.

i.e. something like this:

void printDigits(Print &dev, int digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  dev.print(":");
  if(digits < 10)
    dev.print('0');
  dev.print(digits);
}

And to use it, pass in the device where you want the output to go:

printDigits(Serial, value);

or

printDigits(lcd, value);

or

printDigits(lcd, minute());

etc...

--- bill

4

My guess is that DS1307 library print status status message on your lcd, and you see some remainings of it.
If you do a lcd.clear() before you start to print your own text I think it will be fine.

5

Hello all

thanks for the replies and suggestions!

i worked through my problem and cured it late last night what i did might not be the best way of doing it but now it works!!!

as i learn arduino again hopefully i can get my coding down to the elegant forms that experienced arduino programmers can produce

thanks james