Mini Elevator Working Model with Floor Control and Position Display

An elevator controller is a beautiful control problem in miniature: it must remember which floors were requested, decide direction, stop precisely at each floor, hold the doors, and never move with the doors open. Students usually meet such sequencing only as ladder-logic diagrams; building it physically makes every state transition visible. This project implements a 3-floor elevator model: a foam-board shaft tower, a cabin hung on a string over a pulley driven by a DC gear motor, floor-position sensing with IR sensors, call buttons on each floor plus cabin buttons, and a 7-segment display announcing the current floor. The Arduino firmware runs the full service logic — request queue, direction priority, floor stop, door-timing pause — so the demo behaves like the real machine it models.

1. A passenger presses a landing call button or a cabin destination button; the request enters the firmware's floor queue.
2. The Arduino decides direction from the queue using collective (direction-priority) logic and starts the DC gear motor via the driver.
3. The cabin rises or lowers on the string hoist; the 7-segment display tracks the last passed floor and the direction LED lights.
4. When the cabin reaches a requested floor, its tab triggers that floor's IR sensor and the firmware stops the motor.
5. The cabin dwells for the configured door-timing interval, then the request is cleared and the next queued floor is served.
6. Limit switches at shaft top and bottom provide hardware over-travel cutoffs regardless of firmware state.

Tech stack:

• Arduino Uno (ATmega328P)
• DC gear motor + L298N driver
• Pulley-and-string hoist, foam-board shaft tower
• 3 × IR position sensors, 2 × limit switches
• Floor call buttons + cabin buttons
• 7-segment floor display + direction LEDs
• Arduino IDE (C/C++ firmware)

• [3-floor working lift] A cabin travels a foam-board shaft on a pulley-and-string hoist driven by a DC gear motor, stopping at three defined floors.
• [Floor call system] Call buttons on each landing plus cabin destination buttons feed a request queue, like a real elevator panel.
• [IR floor-position sensing] An IR sensor at each floor detects the cabin's arrival; the motor stops on sensor trigger for repeatable floor alignment.
• [Direction-priority logic] Firmware serves requests in the current travel direction first (collective control), the same strategy real elevators use.
• [7-segment floor display] The current floor is shown on a 7-segment display, with an arrow LED indicating travel direction.
• [Door-timing pause] The cabin dwells at each served floor for a configurable interval before continuing, modeling door open/close timing.
• [Over-travel protection] Limit switches at the top and bottom of the shaft cut the motor as a hardware safety independent of the firmware.

• 3-floor shaft tower with cabin and hoist mechanism
• DC gear motor with driver and pulley set
• IR floor sensors, limit switches, buttons, display
• Arduino with elevator-control firmware
• Wiring diagrams and assembly guide
• Project report PDF (control sequencing, sensing, collective logic, safety)
• PPT presentation for final review
• Viva Q&A preparation document

• A 3-floor string-hoist model demonstrates control logic; it is not a scale replica of traction-elevator mechanics (counterweights, guide rails, safety gears).
• Floor alignment repeatability is a design target of a few millimetres; string stretch over time needs the re-tensioning step in the guide.
• The cabin load limit (~200 g) is a design target — it carries demo weights, not real payloads.
• Door motion is modeled as a timed dwell; there are no moving doors in this build (listed as future scope).
• Collective control is implemented for 3 floors; the logic would need extension for taller shafts.