time and date library

Using Arduino Programming Questions
#1

I’m trying to use the time and date library and i’m getting odd results - probably something i don’t understand. I can use the setTime with a single argument of seconds since 1970 but when i try to use it with multiple arguments [setTime(hr,min,sec,day,month,yr)] I get anomalous results.

The following is adapted from the serial example - it should show the same time twice(I thought) but no such luck. I tried it on arduino 21 just in case but no change.

/* 
 * TimeSerial.pde
 * you can send the number on the next line to set the clock to noon Jan 1 2010
 1262347200  
 */ 
 
#include <Time.h>  

void setup()  {
  Serial.begin(115200);
  Serial.println("Testing Time Setting Functions");
  setTime(1262347200); // seconds since jan 1 1970
  digitalClockDisplay();  
  setTime(12,0,0,1,1,2010); // another way to set the time setTime(hr,min,sec,day,month,yr)
  digitalClockDisplay();    
}

void loop(){    
}

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(); 
}

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);
}

the results are

Testing Time Setting Functions
12:00:00 1 1 2010
22:22:56 31 10 2020
#2

Arduino 21 on a Duemilanove: Testing Time Setting Functions 12:00:00 1 1 2010 12:00:00 1 1 2010

#3

PaulS:
Arduino 21 on a Duemilanove:
Testing Time Setting Functions
12:00:00 1 1 2010
12:00:00 1 1 2010

huh! Thanks so much for trying it paul. did you download the library recently? I notice it’s got fixes as of july.

running off to get my due…

#4

did you download the library recently?

Half an hour ago...

#5

ok, this is the oddest darned thing. using a diecimila/168 i get correct results, my RBBB with 328 gives incorrect results!

I'll move some processors around and see what's up.

Thanks again paul.

btw is your duemilanove a 168 or a 328.

#6

A 328.

I downloaded 0022, and compiled and tested on a Mega2560. Same (good) results.

#7

ok, took me a while to get a fresh 328 burned but the issue is the particular chip i was using. i suspect maybe a bad memory patch that only showed up with a more complex program. huh!

#8

bill2009: ... I notice it's got fixes as of july.

Good to hear you found the problem. FYI, the recent fix was only to correct the little used convenience macro : daysToTime_t

#9

I want to display date and time on 16*4 lcd . i download DateTime.h library. but code was not complied. reply please

#10

vidya_ACSPL:
I want to display date and time on 16*4 lcd . i download DateTime.h library. but code was not complied. reply please

The DateTime library in the playground is obsolete and was replaced by newer code four years ago. There is a note on the web page for the old DateTime code that provides the link to the latest version: http://playground.arduino.cc/Code/Time.

A little time searching in this forum or with google should turn up a number of examples of LCD clocks built using the Time library.
here is one example: Siliconfish: Arduino LCD Countdown Clock

#11