Gravity Clock

Gravity Clock is an embedded project based on the STC8 microcontroller.
It uses gravity switches to detect the orientation of the clock and automatically controls countdown timers, alarms, and sleep/wake behavior.

Features

• Orientation detection
  1.Uses 2 gravity switches to detect 4 different directions.
  2.Each direction has its own countdown timer.

• Countdown timer
  1.When the device is tilted to a direction, the corresponding countdown starts.
  2.Countdown values can be set individually for each direction using buttons.

• Alarm
  1.When a countdown reaches zero, an alarm sounds.
  2.After the alarm ends, the device automatically enters sleep mode.

• Sleep/Wake function
  1.Device sleeps after alarm finishes to save power.
  2.Shaking the device or tilting it to a new direction wakes it up and resumes the current direction's countdown.

• EEPROM storage
  1.Countdown times for each direction can be set with buttons.
  2.Values are stored in EEPROM to retain settings after power-off.

• OLED display
  1.Shows countdown time for each direction.
  2.Supports 4-direction display, adapts to current orientation.

Beeper

1. Uses a passive beeper for alarm notifications.

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Hardware

• Microcontroller: STC8 Series MCU
• Gravity Switches: 2 units (detect 4 directions)
• Buzzer: For alarm notifications (passive)
• Buttons: For setting countdown times
• OLED display: 64*128 Optional, shows current countdown and status (I2C protocol)

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Software

• Written in C for STC8 microcontroller.

• The software is designed with a layered architecture and follows a state machine approach.

• Layered design: Separates low-level device drivers, system abstraction APIs, and high-level control logic for clarity and modularity.

• State machine: The main loop executes business logic based on the current state

• Software architecture is organized into three layers:

  1. Device Driver Layer: Handles direct register access and peripheral interactions.
  2. System Abstraction Layer: Provides higher-level APIs for timers, I2C, UART, GPIO, etc.
  3. Control Logic Layer: Implements the main application logic and state machine.

• Software execution follows a state-driven main loop, where each state executes its corresponding business logic sequentially.

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License

This project is open-source under the MIT License. You are free to use, modify, and distribute it with attribution.

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