Microcontroller Based Project on Automatic Bell System for Schools

We are living in the world of automation where all the activities are getting automated through the use of advanced programmable controllers in home automation and industrial automation systems. An automatic school timer system reduces the effort needed to turn on or off an electric bell manually that gives alarm for certain intervals of time based on school timings. This automatic system is a microcontroller based project that uses a simple basic microcontroller, which makes this product affordable.

Automatic Bell System for Institutions or Schools

Usually conventional methods require a peon or bell operator to attend and operate the bell system for every period and interval in schools and institutions. Such systems need sufficient human efforts to do so, and require advancement in order to become automated – the ones that minimize human efforts. As the bell system is important in schools, homes and industries, automatic operation of this instrument must have to be performed with a precise time controller in an economical way.

This automatic school bell timer system is designed using basic 8051 microcontroller for managing time intervals. Read or Write memory is also necessary for storing bell timings, but for less number of timings this memory is not needed. This system also provides the display of timing information in seven-segment display for a user interface purpose.

This system uses a power-supply block to drive all the circuit components, an 8051 microcontroller to control and manage bell timings, a real-time clock for accurate timing operation, a matrix keypad to enter and configure the bell timings and a seven-segment display to display the time and information. The operation of this system can be easily understood from the above block diagram, wherein the keypad entered timings are stored in the microcontroller, which are responsible for operating the bell based on the program of the microcontroller.

Microcontroller based School Timer Circuit Operation

• The Regulated DC power supply is given to the microcontroller using a power-supply block (In the circuit, it is not given but given in the block diagram). This power-supply block consists of a step-down transformer, a bride rectifier, a filter and a regulator IC. The mains 230V supply is stepped downed to a 12V AC by using the transformer. This AC is rectified to a DC supply by the bridge rectifier and capacitor filters to a pure DC, and then by a regulator that regulates the power to a constant DC to 5V. This power supply drives the entire circuit except the relay and bell devices.

• For making an accurate and precise time controller, DS1307 serial RTC (Real Time Clock) is connected to the microcontroller. This RTC is a low-power, fully binary-coded decimal clock with 56 bytes of SRAM. This clock displays year, month, date, day, hours, minutes and seconds information. In this clock, data and address are serially transferred by I2C bidirectional bus. It also has a built-in backup supply to keep time operation continuous in times of power failures as shown in the figure.
• Matrix keypad is interfaced to the microcontroller for setting and storing the timing values. Various keys are used in this keypad for setting real-time hours and minutes, bell timing operations, and for storing and deleting bell and real timings.
• The Seven-segment display is connected in common anode mode and interfaced to the microcontroller for displaying the timing information.
• Buzzer is switched using relay and the relay coil is energized by the microcontroller.
• The microcontroller has inbuilt flash EPROM memory to store the data that remains even after power failure.
• The microcontroller is programmed in such a way that it accepts the real timing and bell timings and correspondingly sends the controls signals to the seven-segment display and also to the transistor connected to the relay coil.
• When the relay transistor is enabled, it energizes the relay coil so that the path is closed to power the bell device.
• Prior to working with this system we have to configure the real time and bell time values using a matrix keypad. The procedure for the configuration is given below:

Enter the Current real time using the keypad.
Press ‘#’ to store the real time.
Press ‘*’ display that shows all dashes.
Enter the 1st bell ON time.
Press ‘*’ to save the 1st bell ON time.
Continue this procedure for 5 bells.
Press ‘*’ to get the real time

In this way, one can build a school bell timer using simple microcontroller. You might have got clear understanding of this programmable timer with this microcontroller based project. You can also go through some additional microcontroller projects in the below list.

Microcontroller based Projects for Engineering Students

1. GPS/GSM based Vehicle Theft Location Intimation to the Owner Using a Microcontroller
2. Remote Operation of Domestic Appliances’ Control using Android Application
3. Microcontroller Based Fire Detection and Monitoring System in Petro-Mechanical Industries
4. RF Based Accident Indication Using Vibration Sensors
5. XBEE Based Monitoring of Transformer or Generator Parameters Remotely
6. Pick N Place Robot by using Soft Catching Gripper
7. AVR Microcontroller based Humidity Controller
8. Portable Programmable Medication Reminder by using PIC Microcontroller
9. Glowing Of Street Lights by Vehicle Movement Detection
10. Password Based Digital Locking System Using 8051 Microcontroller
11. GPS Speedo Meter based Over Speed Alert System
12. Microcontroller Based Real-time Elevator Control System
13. Detection of Objects by Ultrasonic Means
14. Radio Frequency Communication Based Wireless Notice Board
15. Two Channel Digital Frequency Meters using PIC microcontroller
16. UPS Battery Management in Industries using GSM technology
17. Controlling of Electrical Device Switch by Mobile Phone Operation
18. Radio Frequency Based Unique Office Communication System
19. RF Technology Based Secret Code Enabled Secured Communication
20. Hybrid Pulse Width Modulation Based Analysis of Cascaded Five Level Multilevel Inverter
21. Dynamic Temperature Adjustable and Load Controlling System using TRIAC
22. Power Quality Measurement and Developing Method for Monitor Device
23. Controlling and Monitoring System of Power Grid Devices Using GSM technology
24. Automatic Door Opening System by Sensing Movement
25. Controlling of Dish Position by Infrared Remote
26. Proportional Integral Controller using Thirteen Levels Inverter for PV System Connected by Grid
27. Controlling of Remote Operated Domestic Appliances By Using Android Application
28. Radio Frequency Controlled Robotic Vehicle by Laser Beam Arrangement
29. Parallel Telephone Instrument With Secured Privacy Using 8051 Microcontroller
30. Microcontroller Based High Precision Temperature Indicator

The microcontroller project on school timer with the practical considerations along with the microcontroller based projects’ list provide good information for the engineering students, and therefore, we hope that this article might have rendered a better understanding of the concept to you. Furthermore, for any help in this regard or for any other practical and project related aspects, you can comment in the commenting section given below.

Photo Credits:

• Microcontroller Based Project on School Timer by hostgator
• Microcontroller based Projects by electronicshub
• Automatic Bell System imimg