How to Output Time

Projects Programming
1

What's up people?
I'm wrote some code to emit a 5 volt pulse after a given period. After each pulse I have it call this time function. The problem I have is that this isn't what I want. I went to the time library and I simply cannot understand it. All I want is to have this time function output the time of day, versus the time since I powered on the Arduino. This way I'll be able to come back after forgetting what time I powered it on, while knowing that it should emit the pulse every 10 hours. Can someone help me?

void time()
{
  Serial.print("d=");
  Serial.print(day());
  Serial.print(", h=");
  Serial.print(hour());
  Serial.print(", m=");
  Serial.print(minute());
  Serial.print(", s=");
  Serial.print(second());
  Serial.println(); 
}
3

I don't actually have to remember. I have it give you back how long you asked the period between pulses to be so it is always in the header.

Setting the time is the problem I am having. I've tried this code:

time_t t =now();
Serial.println(second(t));

I tried this just as a test so I wouldn't have to modify my code without knowing whether or not it worked. This will only output a zero for me.

6

I see, so I need to have it ask for the time through the serial monitor? And that would be by using setTime(), but how exactly? Can you give me an example?

8

Take a look at the example in the Time Library called "TimeSerial". It illustrates how to set the time from the Serial Monitor.

9

I am trying to set the time, but the inputs I give aren't the same as the ouputs.

#include <Time.h>

float uTime;

void setup()
{
    Serial.begin(9600);
    Serial.println("Input UNIX time.");
    while(Serial.available() <= 0);
    uTime = Serial.parseFloat();
    Serial.println(uTime);
}

void loop()
{
    delay(2000);
    Serial.println(uTime);
}

If I give an input of "1420054710" I get out "1420054656". Data type issue? Using a double did not help and I thought float was the largest data type. Would using an unsigned float help?

11

Yeah, I know they don't have high precision. I'll remember this.