Virtuabotixrtc.h Arduino Library May 2026

#include <virtuabotixRTC.h>
#include <SD.h>
virtuabotixRTC myRTC(7, 6, 5);
int tempPin = A0;
File dataFile;
void setup() 
Serial.begin(9600);
if (!SD.begin(10)) 
Serial.println("SD Card failed!");
return;

void loop() 
myRTC.updateTime();
// Check if we are within working hours (9 AM to 5 PM)
if (myRTC.hours >= 9 && myRTC.hours < 17)  virtuabotixrtc.h arduino library
int tempReading = analogRead(tempPin);
float voltage = tempReading * (5.0 / 1023.0);
float temperatureC = voltage * 100.0;
// Open file and log
dataFile = SD.open("datalog.txt", FILE_WRITE);
if (dataFile) 
  dataFile.print(myRTC.getDateStr());
  dataFile.print(",");
  dataFile.print(myRTC.getTimeStr());
  dataFile.print(",");
  dataFile.println(temperatureC);
  dataFile.close();
Serial.print("Logged: ");
  Serial.println(temperatureC);

 else 
// Outside working hours: do nothing (or deep sleep)
Serial.println("Outside logging hours. Sleeping...");

delay(60000); // Wait 1 minute between readings

If your DS1302 is running slow, check the voltage on pin 3.3V. Some modules have a diode that drops voltage. Powering the VCC pin with 5V and the backup battery with 3V can cause issues. Ensure the main power matches the chip's spec sheet.

Even a great library has pitfalls. Here is your debugging checklist.

The VirtuabotixRTC.h library is a lightweight Arduino library for interfacing with common real-time clock (RTC) modules based on the DS1307 and similar I²C RTC chips. It provides simple functions to set and read the current time and date, and to convert between raw RTC register values and human-readable formats suitable for embedded projects. #include <virtuabotixRTC

Unlike the more common DS3231 or PCF8523 modules which use I2C, the DS1302 chip relies on a proprietary 3-pin serial interface. The VirtuabotixRTC.h library (originally created by Virtuabotix) abstracts this communication into simple, readable C++ commands.

Key Features:

A minimal example to set and print time: void loop() myRTC

#include <Wire.h>
#include "VirtuabotixRTC.h"
VirtuabotixRTC myRTC(0x68); // typical I2C address for DS1307
void setup() 
  Serial.begin(9600);
  Wire.begin();
  myRTC.setTime(14, 30, 0); // 14:30:00
  myRTC.setDate(3, 15, 4, 26); // Tuesday, 15 April 2026 (example format)
void loop() 
  Time t = myRTC.getTime();
  Date d = myRTC.getDate();
  Serial.print(d.day); Serial.print('/');
  Serial.print(d.month); Serial.print('/');
  Serial.print(d.year); Serial.print(' ');
  Serial.print(t.hour); Serial.print(':');
  Serial.print(t.minute); Serial.print(':');
  Serial.println(t.second);
  delay(1000);

(Adjust struct names and function signatures to match the library version you installed.)