#include <Wire.h>
#include "RTClib.h"

RTC_DS1307 rtc;

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);

  if (!rtc.begin()) {
    Serial.println(" finding RTC");
    while (1);
  }

  if (!rtc.isrunning()) {
    Serial.println("RTC is NOT running, setting time...");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }
}

void loop() {
  DateTime now = rtc.now();
  Serial.print(now.hour()); Serial.print(":");
  Serial.print(now.minute()); Serial.print(":");
  Serial.println(now.second());
  delay(1000);
}