A comprehensive engineering project documenting the design and construction of a fully functional, 100 cm vertical transportation system (Ground + 7 floors). This system operates entirely on Discrete Digital Logic, without the use of microcontrollers like Arduino or ESP-32.
- Height: 100 cm vertical structure.
- Capacity: Ground + 7 floors.
- Logic-Based Control: Built using only combinational and sequential logic components.
- Memory Retention: Implemented hardware registers to store user requests during movement.
- Closed-Loop Feedback: Real-time floor detection using IR sensors.
The system's "brain" is built from discrete ICs:
- Priority Encoder (74148): To handle and prioritize multiple floor requests.
- Magnitude Comparator (7485): To compare the current floor with the target floor for decision making.
- D-Flip-Flops (7474): Used as Command Registers to prevent data loss during transitions.
- Motor Driver (L293D): For controlling the lift motor direction and speed.
- Sensors: IR sensors for precise floor leveling.
- Request Phase: User presses a button; the 74148 encoder converts the request into binary.
- Comparison Phase: The 7485 comparator decides if the elevator should move Up, Down, or stay Idle.
- Execution Phase: The motor driver receives the command while Flip-Flops hold the state until the target is reached.
- Signal Polarity Conflict: Resolved using NOT gates to ensure logic compatibility.
- Clock Synchronization: Solved timing issues between the logic gates and mechanical feedback.
- Mechanical Stability: Designed a dual-pillar structure to handle the 100 cm height smoothly.
This project served as a transition from theoretical classroom concepts to a complex, real-world hardware application. It redefined our approach to problem-solving, proving that "engineering is the ability to turn a desperate problem into a logical, working solution".
Supervised by: Dr. Fatma Sakr.