Digital Alarm Clock Using 20*4 Lcd Display

Real Time Clock with Alarm & Temperature Monitor using Arduino

Circuit Diagram :-

Code :-

//Prateek //www.prateeks.in #include <LiquidCrystal.h> #include <Wire.h> LiquidCrystal lcd(12,11,10,9,8,7); const int button1 = 13; const int button2 = 14; const int button3 = 15; const int alarm_pin = 6; void setup() { pinMode(13, INPUT_PULLUP); pinMode(14, INPUT_PULLUP); pinMode(15, INPUT_PULLUP); pinMode(6, OUTPUT); digitalWrite(alarm_pin, LOW); lcd.begin(20, 4); Wire.begin(); attachInterrupt(digitalPinToInterrupt(2), Alarm, FALLING); } bool alarm1_status, alarm2_status; char Time[] = " : : ", calendar[] = " / /20 ", alarm1[] = "A1: : :00", alarm2[] = "A2: : :00", temperature[] = "T: . C"; byte i, second, minute, hour, day, date, month, year, alarm1_minute, alarm1_hour, alarm2_minute, alarm2_hour, status_reg; void Alarm(){ digitalWrite(alarm_pin, HIGH); } void DS3231_read(){ Wire.beginTransmission(0x68); Wire.write(0); Wire.endTransmission(false); 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(); // Read day from register 3 date = Wire.read(); // Read date from register 4 month = Wire.read(); // Read month from register 5 year = Wire.read(); // Read year from register 6 } void alarms_read_display(){ // Function to read and display alarm1, alarm2 and temperature data byte control_reg, temperature_lsb; char temperature_msb; Wire.beginTransmission(0x68); // Start I2C protocol with DS3231 address Wire.write(0x08); // Send register address Wire.endTransmission(false); // I2C restart Wire.requestFrom(0x68, 11); // Request 11 bytes from DS3231 and release I2C bus at end of reading alarm1_minute = Wire.read(); // Read alarm1 minutes alarm1_hour = Wire.read(); // Read alarm1 hours Wire.read(); // Skip alarm1 day/date register alarm2_minute = Wire.read(); // Read alarm2 minutes alarm2_hour = Wire.read(); // Read alarm2 hours Wire.read(); // Skip alarm2 day/date register control_reg = Wire.read(); // Read the DS3231 control register status_reg = Wire.read(); // Read the DS3231 status register Wire.read(); // Skip aging offset register temperature_msb = Wire.read(); // Read temperature MSB temperature_lsb = Wire.read(); // Read temperature LSB // Convert BCD to decimal alarm1_minute = (alarm1_minute >> 4) * 10 + (alarm1_minute & 0x0F); alarm1_hour = (alarm1_hour >> 4) * 10 + (alarm1_hour & 0x0F); alarm2_minute = (alarm2_minute >> 4) * 10 + (alarm2_minute & 0x0F); alarm2_hour = (alarm2_hour >> 4) * 10 + (alarm2_hour & 0x0F); // End conversion alarm1[8] = alarm1_minute % 10 + 48; alarm1[7] = alarm1_minute / 10 + 48; alarm1[5] = alarm1_hour % 10 + 48; alarm1[4] = alarm1_hour / 10 + 48; alarm2[8] = alarm2_minute % 10 + 48; alarm2[7] = alarm2_minute / 10 + 48; alarm2[5] = alarm2_hour % 10 + 48; alarm2[4] = alarm2_hour / 10 + 48; alarm1_status = bitRead(control_reg, 0); // Read alarm1 interrupt enable bit (A1IE) from DS3231 control register alarm2_status = bitRead(control_reg, 1); // Read alarm2 interrupt enable bit (A2IE) from DS3231 control register if(temperature_msb < 0){ temperature_msb = abs(temperature_msb); temperature[2] = '-'; } else temperature[2] = ' '; temperature_lsb >>= 6; temperature[4] = temperature_msb % 10 + 48; temperature[3] = temperature_msb / 10 + 48; if(temperature_lsb == 0 || temperature_lsb == 2){ temperature[7] = '0'; if(temperature_lsb == 0) temperature[6] = '0'; else temperature[6] = '5'; } if(temperature_lsb == 1 || temperature_lsb == 3){ temperature[7] = '5'; if(temperature_lsb == 1) temperature[6] = '2'; else temperature[6] = '7'; } temperature[8] = 223; // Put the degree symbol lcd.setCursor(10, 0); lcd.print(temperature); // Display temperature lcd.setCursor(0, 2); lcd.print(alarm1); // Display alarm1 lcd.setCursor(17, 2); if(alarm1_status) lcd.print("ON "); // If A1IE = 1 print 'ON' else lcd.print("OFF"); // If A1IE = 0 print 'OFF' lcd.setCursor(0, 3); lcd.print(alarm2); // Display alarm2 lcd.setCursor(17, 3); if(alarm2_status) lcd.print("ON "); // If A2IE = 1 print 'ON' else lcd.print("OFF"); // If A2IE = 0 print 'OFF' } void calendar_display(){ // Function to display calendar switch(day){ case 1: strcpy(calendar, "Sun / /20 "); break; case 2: strcpy(calendar, "Mon / /20 "); break; case 3: strcpy(calendar, "Tue / /20 "); break; case 4: strcpy(calendar, "Wed / /20 "); break; case 5: strcpy(calendar, "Thu / /20 "); break; case 6: strcpy(calendar, "Fri / /20 "); break; case 7: strcpy(calendar, "Sat / /20 "); break; default: strcpy(calendar, "Sat / /20 "); } calendar[13] = year % 10 + 48; calendar[12] = year / 10 + 48; calendar[8] = month % 10 + 48; calendar[7] = month / 10 + 48; calendar[5] = date % 10 + 48; calendar[4] = date / 10 + 48; lcd.setCursor(0, 1); lcd.print(calendar); // Display calendar } 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[7] = second % 10 + 48; Time[6] = second / 10 + 48; Time[4] = minute % 10 + 48; Time[3] = minute / 10 + 48; Time[1] = hour % 10 + 48; Time[0] = hour / 10 + 48; calendar_display(); // Call calendar display function lcd.setCursor(0, 0); lcd.print(Time); // Display time } void Blink(){ byte j = 0; while(j < 10 && (digitalRead(button1) || i >= 5) && digitalRead(button2) && (digitalRead(button3) || i < 5)){ j++; delay(25); } } byte edit(byte x, byte y, byte parameter){ char text[3]; while(!digitalRead(button1) || !digitalRead(button3)); // Wait until button B1 is released while(true){ while(!digitalRead(button2)){ // If button B2 is pressed parameter++; if(((i == 0) || (i == 5)) && parameter > 23) // If hours > 23 ==> hours = 0 parameter = 0; if(((i == 1) || (i == 6)) && parameter > 59) // If minutes > 59 ==> minutes = 0 parameter = 0; if(i == 2 && parameter > 31) // If date > 31 ==> date = 1 parameter = 1; if(i == 3 && parameter > 12) // If month > 12 ==> month = 1 parameter = 1; if(i == 4 && parameter > 99) // If year > 99 ==> year = 0 parameter = 0; if(i == 7 && parameter > 1) // For alarms ON or OFF (1: alarm ON, 0: alarm OFF) parameter = 0; lcd.setCursor(x, y); if(i == 7){ // For alarms ON & OFF if(parameter == 1) lcd.print("ON "); else lcd.print("OFF"); } else{ sprintf(text,"%02u", parameter); lcd.print(text); } if(i >= 5){ DS3231_read(); // Read data from DS3231 DS3231_display(); // Display DS3231 time and calendar } delay(200); // Wait 200ms } lcd.setCursor(x, y); lcd.print(" "); // Print two spaces if(i == 7) lcd.print(" "); // Print space (for alarms ON & OFF) Blink(); // Call Blink function lcd.setCursor(x, y); if(i == 7){ // For alarms ON & OFF if(parameter == 1) lcd.print("ON "); else lcd.print("OFF"); } else{ sprintf(text,"%02u", parameter); lcd.print(text); } Blink(); if(i >= 5){ DS3231_read(); DS3231_display();} if((!digitalRead(button1) && i < 5) || (!digitalRead(button3) && i >= 5)){ i++; // Increment 'i' for the next parameter return parameter; // Return parameter value and exit } } } void loop() { if(!digitalRead(button1)){ // If B1 button is pressed i = 0; hour = edit(0, 0, hour); minute = edit(3, 0, minute); while(!digitalRead(button1)); // Wait until button B1 released while(true){ while(!digitalRead(button2)){ // If button B2 button is pressed day++; // Increment day if(day > 7) day = 1; calendar_display(); // Call display_calendar function lcd.setCursor(0, 1); lcd.print(calendar); // Display calendar delay(200); } lcd.setCursor(0, 1); lcd.print(" "); // Print 3 spaces Blink(); lcd.setCursor(0, 1); lcd.print(calendar); // Print calendar Blink(); // Call Blink function if(!digitalRead(button1)) // If button B1 is pressed break; } date = edit(4, 1, date); // Edit date month = edit(7, 1, month); // Edit month year = edit(12, 1, year); // Edit year // 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 time & calendar 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); // Write day 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(200); } if(!digitalRead(button3)){ // If B3 button is pressed while(!digitalRead(button3)); // Wait until button B3 released i = 5; alarm1_hour = edit(4, 2, alarm1_hour); alarm1_minute = edit(7, 2, alarm1_minute); alarm1_status = edit(17, 2, alarm1_status); i = 5; alarm2_hour = edit(4, 3, alarm2_hour); alarm2_minute = edit(7, 3, alarm2_minute); alarm2_status = edit(17, 3, alarm2_status); alarm1_minute = ((alarm1_minute / 10) << 4) + (alarm1_minute % 10); alarm1_hour = ((alarm1_hour / 10) << 4) + (alarm1_hour % 10); alarm2_minute = ((alarm2_minute / 10) << 4) + (alarm2_minute % 10); alarm2_hour = ((alarm2_hour / 10) << 4) + (alarm2_hour % 10); // Write alarms data to DS3231 Wire.beginTransmission(0x68); // Start I2C protocol with DS3231 address Wire.write(7); // Send register address (alarm1 seconds) Wire.write(0); // Write 0 to alarm1 seconds Wire.write(alarm1_minute); // Write alarm1 minutes value to DS3231 Wire.write(alarm1_hour); // Write alarm1 hours value to DS3231 Wire.write(0x80); // Alarm1 when hours, minutes, and seconds match Wire.write(alarm2_minute); // Write alarm2 minutes value to DS3231 Wire.write(alarm2_hour); // Write alarm2 hours value to DS3231 Wire.write(0x80); // Alarm2 when hours and minutes match Wire.write(4 | alarm1_status | (alarm2_status << 1)); // Write data to DS3231 control register (enable interrupt when alarm) Wire.write(0); // Clear alarm flag bits Wire.endTransmission(); // Stop transmission and release the I2C bus delay(200); // Wait 200ms } if(!digitalRead(button2) && digitalRead(alarm_pin)){ // When button B2 pressed with alarm (Reset and turn OFF the alarm) digitalWrite(alarm_pin, LOW); // Turn OFF the alarm indicator Wire.beginTransmission(0x68); // Start I2C protocol with DS3231 address Wire.write(0x0E); // Send register address (control register) // Write data to control register (Turn OFF the occurred alarm and keep the other as it is) Wire.write(4 | (!bitRead(status_reg, 0) & alarm1_status) | ((!bitRead(status_reg, 1) & alarm2_status) << 1)); Wire.write(0); // Clear alarm flag bits Wire.endTransmission(); // Stop transmission and release the I2C bus } DS3231_read(); // Read time and calendar parameters from DS3231 RTC alarms_read_display(); // Read and display alarms parameters DS3231_display(); // Display time & calendar delay(50); // Wait 50ms }

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