Automatic School Bell broken

Projects General Guidance
1

I am making an automatic school bell which will ring at certain times without the need of human input. However i am experiencing some problems which i have tried to solve myself tho sadly i have failed.

The problem i am experiencing currently is that the rtc doesn't connect with local time and the LCD while ligthing up doesn't show any changes

I am using this youtube video as a refence to help me
https://youtu.be/IXZoSdbT4Dw?si=Buo0EKpN55FgWPyW

This is the code they had given me

#include (Wire.h) //instead of parenthesis () put angle bracket as YouTube description does not allow angle bracket
#include (LiquidCrystal_I2C.h)
#include (DS1302.h)
// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x3F, 16, 2);

int Hour;
int Min;
int Sec;
int period;
int in1 = 8; 
int in2 = 9;
int activate=0;
Time t;

// Init the DS1302
DS1302 rtc(2, 3, 4);

void setup()
{
pinMode(8, OUTPUT);
pinMode(9, OUTPUT); 
// Set the clock to run-mode, and disable the write protection
rtc.halt(false);
rtc.writeProtect(false);

// Setup LCD to 16x2 characters
lcd.begin();
Serial.begin(9600);

// The following lines can be commented out to use the values already stored in the DS1302
// rtc.setDOW(SUNDAY); // Set Day-of-Week to FRIDAY
// rtc.setTime(10, 30, 30); // Set the time to 12:00:00 (24hr format)
// rtc.setDate(23, 03, 2020); // Set the date to August 6th, 2010

}

void loop()
{
// Display time on the right conrner upper line

lcd.setCursor(0, 0);
lcd.print("Time: ");
lcd.setCursor(6, 0);
lcd.print(rtc.getTimeStr());
t = rtc.getTime();
Hour = t.hour;
Min = t.min;
Sec = t.sec;

//Display Period Number
lcd.setCursor(0, 1);
lcd.print("Period No: ");
lcd.setCursor(11, 1);
lcd.print(period);

//Period timing, when bell will ring, you can add more period if you want
if ((Hour== 7 && Min== 0 && Sec(= 5)||(Hour== 7 && Min== 30 && Sec(= 5)||(Hour== 8 && Min== 0 && Sec(= 5)||(Hour== 8 && Min== 30 && Sec(= 5)||(Hour== 9 && Min== 30 && Sec(= 5)||(Hour== 10 && Min== 0 && Sec(= 5)||(Hour== 10 && Min== 30 && Sec(= 5)||(Hour== 11 && Min== 0 && Sec(= 5)) {
digitalWrite(in1, HIGH); 
digitalWrite(in2, LOW);

Serial.println("motor is running");
if (activate == 0){
period = period +1;
activate =1;
}
}
else if (Hour== 9 && Min== 0 && Sec(= 7) { // Recess break time (Long ring bell)
digitalWrite(in1, HIGH); 
digitalWrite(in2, LOW);
lcd.setCursor(11, 1);
lcd.print("Break");
delay(500);
lcd.clear();
}
else if (Hour== 11 && Min== 30 && Sec(= 7) { // School time over (Long Ring bell)
digitalWrite(in1, HIGH); 
digitalWrite(in2, LOW);
lcd.setCursor(11, 1);
lcd.print("Over");
period =0;
delay(500);
lcd.clear();
}

else { // stop motor
digitalWrite(in1, LOW); 
digitalWrite(in2, LOW);
activate =0;
}

delay (500);
}

This is my first attempt of fixing the code

#include <Wire.h> //instead of parenthesis () put angle bracket as YouTube description does not allow angle bracket
#include <LiquidCrystal_I2C.h>
#include <DS1302.h>
// Set the LCD address to 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x3F, 16, 2);

int Hour;
int Min;
int Sec;
int period;
int in1 = 8; 
int in2 = 9;
int activate=0;
Time t;

// Init the DS1302
DS1302 rtc(2, 3, 4);

void setup()
{
pinMode(8, OUTPUT);
pinMode(9, OUTPUT); 
// Set the clock to run-mode, and disable the write protection
rtc.halt(false);
rtc.writeProtect(false);

// Setup LCD to 16x2 characters
lcd.begin();
Serial.begin(9600);

// The following lines can be commented out to use the values already stored in the DS1302
// rtc.setDOW(SUNDAY); // Set Day-of-Week to FRIDAY
// rtc.setTime(10, 30, 30); // Set the time to 12:00:00 (24hr format)
// rtc.setDate(23, 03, 2020); // Set the date to August 6th, 2010

}

void loop()
{
// Display time on the right conrner upper line

lcd.setCursor(0, 0);
lcd.print("Time: ");
lcd.setCursor(6, 0);
lcd.print(rtc.getTimeStr());
t = rtc.getTime();
Hour = t.hour;
Min = t.min;
Sec = t.sec;

//Display Period Number
lcd.setCursor(0, 1);
lcd.print("Period No: ");
lcd.setCursor(11, 1);
lcd.print(period);

//Period timing, when bell will ring, you can add more period if you want
if ((Hour== 7 && Min== 0 && Sec(= 5)||(Hour== 7 && Min== 30 && Sec(= 5)||(Hour== 8 && Min== 0 && Sec(= 5)||(Hour== 8 && Min== 30 && Sec(= 5)||(Hour== 9 && Min== 30 && Sec(= 5)||(Hour== 10 && Min== 0 && Sec(= 5)||(Hour== 10 && Min== 30 && Sec(= 5)||(Hour== 11 && Min== 0 && Sec(= 5)) {
digitalWrite(in1, HIGH); 
digitalWrite(in2, LOW);

Serial.println("motor is running");
if (activate == 0){
period = period +1;
activate =1;
}
}
else if (Hour== 9 && Min== 0 && Sec(= 7) { // Recess break time (Long ring bell)
digitalWrite(in1, HIGH); 
digitalWrite(in2, LOW);
lcd.setCursor(11, 1);
lcd.print("Break");
delay(500);
lcd.clear();
}
else if (Hour== 11 && Min== 30 && Sec(= 7) { // School time over (Long Ring bell)
digitalWrite(in1, HIGH); 
digitalWrite(in2, LOW);
lcd.setCursor(11, 1);
lcd.print("Over");
period =0;
delay(500);
lcd.clear();
}

else { // stop motor
digitalWrite(in1, LOW); 
digitalWrite(in2, LOW);
activate =0;
}

delay (500);
}

and this is the code my friend had given me after they tried to fix it


#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DS1302.h>

// Set the LCD address to 0x3F for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x3F, 16, 2);

// Define your variables
int Hour;
int Min;
int Sec;
int period;
int in1 = 8; 
int in2 = 9;
int activate = 0;

// Create an instance of the DS1302 class
DS1302 rtc(2, 3, 4); // Adjust the pin numbers as needed

void setup() {
    pinMode(in1, OUTPUT);
    pinMode(in2, OUTPUT); 

    // Set the clock to run-mode, and disable the write protection
    rtc.halt(false);
    rtc.writeProtect(false);

    // Setup LCD to 16x2 characters
    lcd.begin(16, 2); // Corrected to include number of columns and rows
    Serial.begin(9600);

    // Get the current time from the RTC
    Time t = rtc.time(); // Retrieve the current time

    // Print the current time to the Serial Monitor
    Serial.print("Current Time: ");
    Serial.print(t.hr);
    Serial.print(":");
    Serial.print(t.min);
    Serial.print(":");
    Serial.println(t.sec);
}

void loop() {
    // Get the current time from the RTC
    Time t = rtc.time(); // Retrieve the current time again in loop
    Hour = t.hr;
    Min = t.min;
    Sec = t.sec;

    // Display time on the right corner upper line
    lcd.setCursor(0, 0);
    lcd.print("Time: ");
    lcd.setCursor(6, 0);
    lcd.print(Hour);
    lcd.print(":");
    lcd.print(Min);
    lcd.print(":");
    lcd.print(Sec);

    // Display Period Number
    lcd.setCursor(0, 1);
    lcd.print("Period No: ");
    lcd.setCursor(11, 1);
    lcd.print(period);

    // Period timing, when bell will ring
    if ((Hour == 7 && Min == 0 && Sec == 5) || 
        (Hour == 7 && Min == 30 && Sec == 5) || 
        (Hour == 8 && Min == 0 && Sec == 5) || 
        (Hour == 8 && Min == 30 && Sec == 5) || 
        (Hour == 9 && Min == 30 && Sec == 5) || 
        (Hour == 10 && Min == 0 && Sec == 5) || 
        (Hour == 10 && Min == 30 && Sec == 5) || 
        (Hour == 11 && Min == 0 && Sec == 5)) {
        
        digitalWrite(in1, HIGH); 
        digitalWrite(in2, LOW);
        Serial.println("motor is running");
        if (activate == 0) {
            period = period + 1;
            activate = 1;
        }
    } else if (Hour == 9 && Min == 0 && Sec == 7) { // Recess break time
        digitalWrite(in1, HIGH); 
        digitalWrite(in2, LOW);
        lcd.setCursor(11, 1);
        lcd.print("Break");
        delay(500);
        lcd.clear();
    } else if (Hour == 11 && Min == 30 && Sec == 7) { // School time over
        digitalWrite(in1, HIGH); 
        digitalWrite(in2, LOW);
        lcd.setCursor(11, 1);
        lcd.print("Over");
        period = 0;
        delay(500);
        lcd.clear();
    } else { // Stop motor
        digitalWrite(in1, LOW); 
        digitalWrite(in2, LOW);
        activate = 0;
    }

    delay(500);
}

This is a picture and a circuit diagram of what i am building

circuit_image (1)
circuit_image (1)1920×1018 224 KB

IMG20251003105911
IMG202510031059111920×2550 388 KB

Please inform me if i had made any mistakes
THanks for any kind of help

2

Try using LCD address 0x27 instead 0x3F.

LiquidCrystal_I2C lcd(0x27, 16, 2);

Set the RTC to the correct time, otherwise it won't work.

3

Have you tried running 'I2C Scanner' code (as recommended in the video) to determine the I2C address of your LCD?

There is an 'I2C Scanner' in the examples that come with the 'Wire' library.

There are places in your code where an opening bracket '('need to be replaced with the '<' character.
The comment in the first line of the code explains why - the '<' character can't be used in the YouTube description.

I've arrowed them in the following screen capture:

School Bell Code - Arrowed
School Bell Code - Arrowed1360×768 136 KB

Note that there are more in that long line that goes off the screen.

When combined with the equals sign that follows it, it becomes the mathematical operation less than or equal to.

This is how the timing of the bell ringing is achieved. The bell will ring when the seconds are between 0 and 5.
Your code without it will only ring the bell for 1 second.

4

Have you set the date and time of the RTC as explained in the video?

I think that I know the answer to that question as the code that you suggest that you have used has not been edited to show a date later than 23rd March 2020.

The code that it tells you to comment out after running for the first time is already commented out.

School Bell - Setting the Time
School Bell - Setting the Time1360×768 151 KB

You should pay more attention to following the instructions given in the video.

5

Hi @walimelodiameca !

In addition to @JohnLincoln 's posts you should be aware that any RTC will have to be synchronized sooner or later, depending on its accuracy.

For details feel free to read here
https://wolles-elektronikkiste.de/en/ds1302-and-ds1307-rtc-real-time-clock

If you don't want to do this by changing the code almost every week it would be wise

  • to integrate functions to correct date/time by buttons or Serial communication or
  • use a controller that supports WiFi so that you can sync over Internet (if access to the Internet is available of course)

As described on the linked website, you can also opt for a more precise RTC chip to reduce the need for correction.

Good luck!
ec2021

6

Which real time clock module are you using ? Can you link to it. The DS1302, unlike most other real time clock modules, does not use I2C.
Try to find a simple "Hello World" sketch for the LCD and get that working first before attempting to integrate the other components.