Shadow Clock

Shadow Clock is a custom LED strip clock project built around an ESP8266 (Adafruit ESP8266) that displays the current time on a 60-LED circular strip. The project synchronizes time via Wi-Fi using NTP and uses a DS3231 RTC module as a backup when offline. Two Sharp distance sensors (via an ADS1115 ADC) detect proximity to activate the clock display. When no one cast a shadow, the LED strip gradually fades to a full colorful animation

Issues

Distance Sensors: Two Sharp GP2Y0A21YK0F infrared distance sensors. These sensors perform poorly, should switch to the ultrasound proximity

Renderings

At the beginning of this project, a rendering was created to visualize the final design. See the image below for a preview of the clock design:

Features

• Time Synchronization:
  Uses Wi-Fi to update time via an NTP server and writes it to a DS3231 RTC module for backup when offline.

• LED Clock Display:
  Displays the current hour and minute on a 60-LED strip. The minute is indicated in blue and the hour in red (or magenta if both overlap). When no one is near, the LEDs gradually fade into full white.

• Proximity Activation:
  Two Sharp distance sensors (via ADS1115 ADC channels) detect when a user is interact with the clock to activate the clock display.

• Modular Software Architecture:
  Organized code into separate handler files for display, sensor calibration, and time synchronization.

Hardware Components

• ESP8266: Adafruit HUZZAH ESP8266 for processing and Wi-Fi connectivity.
• LED Strip: 60 WS2812B addressable LEDs (1Meter).
• RTC Module: DS3231 for accurate timekeeping.
• ADC: ADS1115 for high-resolution sensor readings.
• Distance Sensors: Two Sharp GP2Y0A21YK0F infrared distance sensors.
• Miscellaneous: Appropriate power supply, wiring, and resistors (I2C pull-ups, etc.).

Wiring & Setup

• I2C Bus:
  The DS3231 and ADS1115 are connected to the ESP8266 via I2C. Ensure proper pull-up resistors (typically 4.7kΩ) are installed on the SDA and SCL lines.

• LED Strip:
  Connect the data line of the LED strip to GPIO2 (D4 on some boards) of the ESP8266. Ensure your power supply can handle the current drawn by the LED strip.

• Distance Sensors:
  The sensors are connected to separate channels on the ADS1115. Calibrate the sensor outputs to map ADC values to distance in centimeters.

Software Structure

The project uses PlatformIO and is organized into the following files and directories:

Shadow_clock/code/
├── include/
│   ├── DisplayHandler.h       # LED display functions (clock and fade)
│   ├── SensorHandler.h        # Sensor calibration functions
│   └── TimeSyncHandler.h      # Wi-Fi/NTP time synchronization functions
├── src/
│   ├── main.cpp               # Main program loop
│   ├── DisplayHandler.cpp     # Implementation of display functions
│   ├── SensorHandler.cpp      # Implementation of sensor calibration
│   └── TimeSyncHandler.cpp    # Implementation of time synchronization
├── images/
│   ├── rendering1.png         # Rendering image 1
└── platformio.ini             # PlatformIO project configuration

Installation

1. Clone the Repository:

   git clone https://github.com/riccifab/Shadow_clock.git
   cd Shadow_clock

2. Open with PlatformIO:
   Open the project folder in VS Code with the PlatformIO extension installed.

3. Configure Wi-Fi Credentials:
   Update ssid and password in main.cpp

4. Build and Upload:
   Use PlatformIO commands to build and upload the firmware to your ESP8266:

   pio run --target upload

5. Monitor Serial Output:
   Open the serial monitor to check debug output:

   pio device monitor

Customization

• Time Display:
  Modify DisplayHandler.cpp to change how the hour and minute indicators are rendered on the LED strip.

• Sensor Calibration:
  Adjust the calibration curve in SensorHandler.cpp according to your measured sensor values.

• Fade-In Effect:
  Change the fade-in duration in main.cpp by modifying the mapping parameters if needed.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgements

• FastLED for the LED library.
• RTClib for RTC functionality.
• NTPClient for time synchronization.
• Shadowplay design inspiration.