Digital Electronics module

This project focuses on designing and implementing a Digital Timer Circuit that can display time in four different formats:

• 30 minutes (Helal’s circuit)
• 25 minutes (Pedro’s circuit)
• 20 minutes (Mehraz’s circuit)
• 15 minutes (Abdullah’s circuit)

Each timer functions independently using counters, flip-flops, and logic gates, and all four circuits are controlled by a 2-bit multiplexer-based control unit. The selected timer output is displayed on a seven-segment display using a BCD to seven-segment decoder.

Why was it created?

• To develop an accurate digital timer using logic circuits.
• To integrate multiple timers into a single controlled system.
• To apply flip-flop-based counters and digital logic for time tracking.
• To simulate and analyze digital circuits using software tools.

How does it work?

Individual Timer Circuits

• Each person designed a separate timer using flip-flops and logic gates.
• The timers count in seconds and minutes up to 15, 20, 25, or 30 minutes before resetting.

Integration Using a Multiplexer (MUX)

• The four timers were combined using a 4:1 multiplexer.
• A 2-bit select input (S0, S1) determines which timer is active.

Time Display System

• The selected timer's 4-bit output is sent to a BCD to seven-segment decoder.
• The decoded signal drives a seven-segment display, showing the time.

Simulation and Validation

• The system was simulated in Multisim to check timing accuracy.
• Simulation results confirmed correct counting, switching, and display output.