LED wont turn on using localtime [ARDUINO]

Question

#include <stdio.h>      
#include <time.h>

time_t now;
struct tm *now_tm;
int h,m,s;

void setup(){
    pinMode(D6,OUTPUT);
}

void loop ()
{
    now = time(NULL);
    now_tm = localtime(&now);
    h = now_tm->tm_hour;
    m = now_tm->tm_min;
    s = now_tm->tm_sec;

    if(h == 17 && m == 0 && s==0)
    {
        digitalWrite(D6,HIGH);
        delay(100000);
        digitalWrite(D6,LOW);
    }
}

I don't know why my LED on pin D6 won't turn on when it's 17:00:00

I tried check it with other IF condition and it worked fine

I count the hour, the minute and the second on visual and they showed the right value

How is Arduino supposed to know what time is it? Put a `Serial.println("Debug message");` inside the if so you can see if you are actually entering the condition block (which most likely you are not) — , Nov 27 '18 at 12:02

score 0 · Answer 1 · answered Nov 28 '18 at 18:01

In order for your code to work, you need to have some type of external clock (arduino doesn't know what time it is) e.g. DS3231. You can find tutorial about it here: https://howtomechatronics.com/tutorials/arduino/arduino-ds3231-real-time-clock-tutorial/

LED wont turn on using localtime [ARDUINO]

1 Answers1