DS3231 Real Time Clock Interfacing With Arduino

In today's world, time plays a critical role in almost every aspect of life. The ability to track time with precision and accuracy is essential, whether you are managing a large corporation or building a small hobby project. A real-time clock (RTC) is an electronic device that is used to track time with high accuracy. The DS3231 RTC module is one of the most popular RTC modules available in the market. This article will provide an in-depth overview of the DS3231 Real-Time Clock and discuss how it can be used in an RTC project with Arduino interfacing. DS3231 Real-Time Clock: The DS3231 is a low-cost, highly accurate, and highly stable real-time clock (RTC) module. It is a popular choice among hobbyists and professionals alike due to its ease of use and low power consumption. The module is designed to provide accurate timekeeping and datekeeping in a wide range of applications, including time-based functions, alarms, and calendars. The DS3231 RTC module is a highly integrated chip that contains a crystal oscillator, a temperature sensor, and a timekeeper circuit. The module operates on a low power supply voltage of 2.3V to 5.5V, making it ideal for battery-powered devices. The module has an accuracy of ±2 ppm at room temperature, which makes it highly reliable for long-term timekeeping applications. Arduino Interfacing: The DS3231 RTC module can be easily interfaced with an Arduino microcontroller. The Arduino microcontroller is an open-source platform that provides a user-friendly environment for programming and interfacing with various electronic devices. The DS3231 RTC module can be connected to the Arduino microcontroller through the I2C interface. To interface the DS3231 RTC module with an Arduino microcontroller, you will need to download the DS3231 library from the Arduino library manager. The library provides a set of functions that allow the Arduino microcontroller to communicate with the DS3231 RTC module. Once the library is installed, you can use the sample code provided in the library to interface the DS3231 RTC module with the Arduino microcontroller. RTC Project: An RTC project is a project that involves the use of a real-time clock module to track time and perform time-based functions. The DS3231 RTC module can be used in various RTC projects, including alarm clocks, timers, dataloggers, and more. One of the most popular RTC projects is an alarm clock. An alarm clock is a device that is designed to wake up a person at a specified time. The DS3231 RTC module can be used to provide accurate timekeeping for an alarm clock project. The Arduino microcontroller can be used to control the alarm clock's functions, such as setting the alarm time and activating the alarm. Another popular RTC project is a data logger. A data logger is a device that is used to record data over time. The DS3231 RTC module can be used to provide accurate timekeeping for a data logger project. The Arduino microcontroller can be used to read sensor data and store it on an SD card along with the timestamp. Conclusion: In conclusion, the DS3231 Real-Time Clock module is a highly reliable and accurate timekeeping module that can be used in a wide range of RTC projects. The module is easy to use and can be easily interfaced with an Arduino microcontroller through the I2C interface. Whether you are building an alarm clock, data logger, or any other RTC project, the DS3231 RTC module is a great choice. With its low power consumption, high accuracy, and stable timekeeping, the DS3231 RTC module is a must-have for any timekeeping project.

Program for RTC

// Real time clock and calendar with set buttons using DS3231 and Arduino #include <Wire.h> // include Wire library code (needed for I2C protocol devices) #include <LiquidCrystal_I2C.h> // include Wire library code (needed for I2C protocol devices) LiquidCrystal_I2C lcd(0x27,16,2); void setup() { Serial.begin(9600); Wire.begin(); // Join i2c bus lcd.init(); lcd.backlight(); pinMode(8, INPUT); pinMode(9,OUTPUT); } char Time[] = "Time: "; char ti[] ="Time: HH:MM:SS"; char Calendar[]="Date: "; char ca[]="Date: DD/MM/YY"; byte i,pre, second, minute, hour,day, date, month, year; char bs = ""; //String d,h; int x=0,y=0,k=0,l=0,al=0; byte h[2], m[2], d[2]; void DS3231_display() { // Convert BCD to decimal second = (second >> 4) * 10 + (second & 0x0F); minute = (minute >> 4) * 10 + (minute & 0x0F); hour = (hour >> 4) * 10 + (hour & 0x0F); date = (date >> 4) * 10 + (date & 0x0F); month = (month >> 4) * 10 + (month & 0x0F); year = (year >> 4) * 10 + (year & 0x0F); // End conversion Time[12+i] = second % 10 + 48; //Converting to ASCII Time[11+i] = second / 10 + 48; Time[10+i] = ':'; Time[9+i] = minute % 10 + 48; Time[8+i] = minute / 10 + 48; Time[7+i] = ':'; Time[6+i] = hour % 10 + 48; Time[5+i] = hour / 10 + 48; Calendar[12+i] = year % 10 + 48; Calendar[11+i] = year / 10 + 48; Calendar[10+i] = '/'; Calendar[9+i] = month % 10 + 48; Calendar[8+i] = month / 10 + 48; Calendar[7+i] = '/'; Calendar[6+i] = date % 10 + 48; Calendar[5+i] = date / 10 + 48; lcd.setCursor(0,0); lcd.print(Time); lcd.setCursor(0,1); lcd.print(Calendar); } int editbutton() { int alarm,hp,mp,dp,tp,yp; alarm = 0; hp = hour; mp = minute; dp = date; tp = month; yp = year; int j,k=1; char ins1[] = "Leave button"; char ins2[] = "Press button"; for(j=0;j<k;j++) { lcd.clear(); if(digitalRead(8)==0) { hour = 0; while(true) { hour = hour + 1; if(digitalRead(8)==1) break; if(hour > 23) { hour = 0; lcd.clear(); } lcd.setCursor(0,0); lcd.print(ins1); lcd.setCursor(0,1); lcd.print("hour "); lcd.print(hour); delay(500); } } lcd.clear(); if(digitalRead(8)==1) { minute = 0; while(true) { minute = minute + 1; if(digitalRead(8)==0) break; if(minute > 59) { minute = 0; lcd.clear(); } lcd.setCursor(0,0); lcd.print(ins2); lcd.setCursor(0,1); lcd.print("minute "); lcd.print(minute); delay(500); } } lcd.clear(); if(digitalRead(8)==0) { date = 0; while(true) { date = date + 1; if(digitalRead(8)==1) break; if(date > 30) { date = 0; lcd.clear(); } lcd.setCursor(0,0); lcd.print(ins1); lcd.setCursor(0,1); lcd.print("date "); lcd.print(date); delay(500); } } lcd.clear(); if(digitalRead(8)==1) { month = 0; while(true) { month = month + 1; if(digitalRead(8)==0) break; if(month > 12) { month = 0; lcd.clear(); } lcd.setCursor(0,0); lcd.print(ins2); lcd.setCursor(0,1); lcd.print("month "); lcd.print(month); delay(500); } } lcd.clear(); if(digitalRead(8)==0) { year = 0; while(true) { year = year + 1; if(digitalRead(8)==1) break; if(year > 50) { year = 0; lcd.clear(); } lcd.setCursor(0,0); lcd.print(ins1); lcd.setCursor(0,1); lcd.print("year "); lcd.print(year); delay(500); } } lcd.clear(); for (int tc=0; tc<5 ; tc++) { if(alarm == 0) { lcd.setCursor(0,0); lcd.print("To Set Alarm 1"); lcd.setCursor(0,1); lcd.print("Press Button "); lcd.print(tc); delay(2000); } if ((digitalRead(8) == 0 && alarm < 2) || k == 2) { lcd.clear(); h[alarm] = hour - 1; m[alarm] = minute - 1; d[alarm] = date - 1; alarm = alarm + 1; tc = 0; lcd.setCursor(0,0); lcd.print("Alarm "); lcd.print(alarm); lcd.print(" Set"); delay(5000); } lcd.clear(); if(alarm == 1) { lcd.setCursor(0,0); lcd.print("To Set Alarm 2"); lcd.setCursor(0,1); lcd.print("Hold Button Now"); delay(2000); lcd.clear(); } if(digitalRead(8) == 0 && k<=1) { lcd.setCursor(0,0); lcd.print("Hold Button"); lcd.setCursor(0,1); lcd.print("Set Alarm Time"); delay(1000); k=k+1; } if(k==2) { break; } delay(2000); //lcd.clear(); } } if(alarm != 0) { hour = hp; minute = mp; date = dp; month = tp; year = yp; } return alarm; } void loop() { while(digitalRead(8)==0) { al = editbutton(); Serial.println(al); if(al==0) { hour = hour - 1; minute = minute - 1; date = date - 1; month = month - 1; year = year - 1; } // Convert decimal to BCD minute = ((minute / 10) << 4) + (minute % 10); hour = ((hour / 10) << 4) + (hour % 10); date = ((date / 10) << 4) + (date % 10); month = ((month / 10) << 4) + (month % 10); year = ((year / 10) << 4) + (year % 10); // End conversion // Write data to DS3231 RTC Wire.beginTransmission(0x68); // Start I2C protocol with DS3231 address Wire.write(0); // Send register address Wire.write(0); // Reset sesonds and start oscillator Wire.write(minute); // Write minute Wire.write(hour); // Write hour Wire.write(day); // NOT USED Wire.write(date); // Write date Wire.write(month); // Write month Wire.write(year); // Write year Wire.endTransmission(); // Stop transmission and release the I2C bus delay(300); // Wait 300ms } i=1; y = y + 1; if (al > 0) /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// { for (int x =0;x<al;x++) { if(d[x] == date && h[x] == hour && m[x] == minute) { lcd.clear(); lcd.setCursor(0,0); lcd.print("Alarm SET ON"); delay(500); digitalWrite(9, HIGH); delay(500); digitalWrite(9, LOW); } else { digitalWrite(9,LOW); } } } if(Serial.available()>0) { bs = Serial.read(); if(bs == 'e') { Serial.println("Enter Hour"); while(x==0) { x = Serial.parseInt(); } Serial.println(x); pre = hour; hour = x; x=0; } if(hour > 23) { Serial.println("Invalid Entry For Hour"); hour = pre; } if(bs == 'e') { Serial.println("Enter Minute"); while(x==0) { x = Serial.parseInt(); } Serial.println(x); pre = minute; minute = x; x=0; } if(minute > 59) { Serial.println("Invalid Entry For Minute"); minute = pre; } if(bs == 'e') { Serial.println("Enter date"); while(x==0) { x = Serial.parseInt(); } Serial.println(x); pre = date; date = x; x=0; } if(date > 31) { Serial.println("Invalid Entry For date"); date = pre; } if(bs == 'e') { Serial.println("Enter Month"); while(x==0) { x = Serial.parseInt(); } Serial.println(x); pre = month; month = x; x=0; } if(month > 12) { Serial.println("Invalid Entry For Month"); month= pre; } if(bs == 'e') { Serial.println("Enter Year"); while(x==0) { x = Serial.parseInt(); } Serial.println(x); pre = year; year = x; x=0; } if(year > 25) { Serial.println("Invalid Entry For Year"); year = pre; } // Convert decimal to BCD minute = ((minute / 10) << 4) + (minute % 10); hour = ((hour / 10) << 4) + (hour % 10); date = ((date / 10) << 4) + (date % 10); month = ((month / 10) << 4) + (month % 10); year = ((year / 10) << 4) + (year % 10); // End conversion if(bs=='v') { Serial.println(al); Serial.println(h[0]); Serial.println(hour); Serial.println(m[0]); Serial.println(minute); Serial.println(d[0]); Serial.println(date); } // Write data to DS3231 RTC Wire.beginTransmission(0x68); // Start I2C protocol with DS3231 address Wire.write(0); // Send register address Wire.write(0); // Reset sesonds and start oscillator Wire.write(minute); // Write minute Wire.write(hour); // Write hour Wire.write(day); // NOT USED Wire.write(date); // Write date Wire.write(month); // Write month Wire.write(year); // Write year Wire.endTransmission(); // Stop transmission and release the I2C bus delay(300); // Wait 300ms } Wire.beginTransmission(0x68); // Start I2C protocol with DS3231 address Wire.write(0); // Send register address Wire.endTransmission(false); // I2C restart Wire.requestFrom(0x68, 7); // Request 7 bytes from DS3231 and release I2C bus at end of reading second = Wire.read(); // Read seconds from register 0 minute = Wire.read(); // Read minuts from register 1 hour = Wire.read(); // Read hour from register 2 day = Wire.read(); //NOT USED date = Wire.read(); // Read date from register 4 month = Wire.read(); // Read month from register 5 year = Wire.read(); // Read year from register 6 DS3231_display(); // Display time & calendar if(y==5) { Serial.println("To edit date and time enter e"); y=0; } Serial.println(ti); Serial.println(Time); Serial.println(ca); Serial.println(Calendar); Serial.println("\n"); delay(1000); // Wait 50ms }

Circuit Diagram For RTC