Automatic School Bell

Jahanzeb Gul     
Project non tested



This project is an Automatic School bell system. Such a system triggers a bell (or operates any other load) at predifined time. In this version some advanced features are introduced:

  • 16×2 LCD Display ( Displays current date, time and day)
  • 4×4 Keypad for Inputs
  • Stand alone product ( no PC required to program or maintain ringing schedule)
  • No battery required to maintain clock and ringing schedule
  • Variable ringing time
  • Max 10 bells can be set
  • Custom Weekend filters
  • Monthly OFF / Weekly OFF
  • Half Day
  • Total AC Power Handling : 1000W (240V 5A)
  • Connect as many AC electronic bells in parallel form
  • Built-in back up battery supply
  • Built in permanent memory for bell timings
  • Auto-memory scan on system startup

I used PIC18f4520 microcontroller as the brain of the system. RTC1307 IC is used to maintain the clock,date and day with a 3V backup voltage battery. Bell timings are stored in the internal EEPROM of mcu.

MCU is reading time from RTC through I2C Serial protocol and compares the current time with stored memory time in a continous while(1) loop.

MM74C922 decoder IC is used for keyboard. Reading the sixteen buttons is done using 4-bits output of decoder IC.









32 Response on “Automatic School Bell

  1. Only the .hex file is available. You can try to contact the author at his email found below the project’s title.

  2. khoza, so basically you want to use someone’s project as your own. what have you came up with in this project?! i understand you want to use this schematic the way it is, but that is plagarism. sow us what you have done so far then we can see how we help you.

  3. i am university student .i am doing this project for my university final year project can you please email me the original i want to do little bit modification in this project .if i get success in this project it will implement in my university

  4. Hello everyone… I am the designer of this project. First of all thank you very much for liking the project. This project was done 4 Years ago and the final device is still installed in a School working perfectly. I receive alot of emails regarding the source code but unfortunately the code files are deleted because of some virus attack at that time… So source code files are not available… Some people are also having difficulty in running the demo in Proteus. I made a video for demo as well 3 years ago and published it on youtube. Here is the link if anyone wants to know how to set the bells etc…

    Thanks again…

    1. Only the .hex file is available. You can try to contact the author at his email found below the project’s title.

  5. So many whiny would-be plagiarists! Thanks for posting this. I’m going to use the details for helping me with my Pic powered cuckoo clock. Again, thank you for sharing. The rest of you, stop spending time whining on the internet and spend more time learning about your subjects!

    1. You will need to modify the code a bit. But the issue is that it is not available from the author at this moment. I would suggest to contact the author for further help.

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