gistfile1.txt

// GetCode.ino
// 
// Basic example for the TOTP library
//
// This example uses the opensource SwRTC library as a software real-time clock
// you can download from https://github.com/leomil72/swRTC
// for real implementation it's suggested the use of an hardware RTC

#include "sha1.h"
#include "TOTP.h"
#include "RTClib.h"

// The shared secret is MyLegoDoor
uint8_t hmacKey[] = {ENTER YOURSELF};

TOTP totp = TOTP(hmacKey, 10);
RTC_DS3231 rtc;
char code[7];


void setup() {
  
  Serial.begin(9600);
}

void loop() {
  DateTime now = rtc.now();
  char* newCode = totp.getCode(now.unixtime());
  if(strcmp(code, newCode) != 0) {
    strcpy(code, newCode);
    Serial.print(code);
    Serial.print(" - ");
    Serial.println(now.unixtime());
  }  
}