Automatic Padlock Opening Controller

Project Description

The Automatic Padlock Opening Controller is a microcontroller-based system designed to automatically open a padlock using a motor-driven dial mechanism. Users interact with the system via a 4x4 keypad and monitor machine status in the Arduino Serial Monitor.

Core Functions

• Set and track dial position (0-39 for a 40-mark lock).
• Open padlock in automatic mode with combination sequence logic.
• Provide one-click manual dial control in both directions.
• Display mode status, prompts, and errors via Serial Monitor.

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System Modes

1) Setup Mode

• User enters initial dial position through keypad.
• System stores the position and prepares for operation.
• Dial position and prompts are shown in Serial Monitor.

2) Automatic Mode

• User enters three combination numbers.
• System performs lock sequence:
  1. Two full turns clockwise (RIGHT) to first number.
  2. One full turn counter-clockwise (LEFT), passing first number, to second number.
  3. One turn clockwise (RIGHT) to third number.
• System prompts user to pull shackle after completion.

3) Manual Mode

• User rotates dial manually with keypad:
  • 1: one-click clockwise
  • 2: one-click counter-clockwise

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Free Time System (FTS) Architecture

A. Initialization Function

• Initializes variables, flags, and mode defaults.

B. Machine Status Selection Function

• Reads keypad and selects operating mode.

C. Machine Setup Data Function

• Captures initial dial position and transitions system to ready state.

D. Automatic Function

• Executes complete lock-opening sequence from three user-entered numbers.

E. Manual Function

• Executes one-click movement per key press.

F. Programming Function

• Not required in this project; not implemented.

G. Output Control Supervisor

• Prints mode changes, prompts, and machine status to Serial Monitor.

H. Error Function

• Handles invalid input and run-time fault messages.

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Human-Machine Interface (Serial Monitor)

The interface displays:

• Current mode
• Dial position
• Combination input progress
• Error and reset messages

Example main menu:

EME-154 Mechatronics
Free Time System
Yusen Hu
****************************************
            OPERATION MENU
****************************************
1. Manual Operation
2. Automatic Operation
3. Machine Data Set-Up
5. Exit

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System Development Summary

Key development items completed:

• Implemented dial movement helpers:
  • moveCwToDialNO()
  • moveCcwToDialNO()
• Implemented automatic sequence in ACSfunction().
• Completed setup and automatic menu text blocks.
• Added/updated emergency recovery in ERTfunction().
• Added PI controller parameters scaffold (KI, INTEGRAL_LIMIT) for experimentation.

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Challenges Encountered

1. Motor tuning difficulty
   • Finding reliable MIN_PWM, KP, KI for different motor friction points.
2. Memory / compatibility constraints
   • Adopted F() macro usage for many Serial strings.

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