Date: October 4, 2024
CatTrack is a behavior tracking device designed to monitor and classify feline activity using an accelerometer and temperature sensor, while providing real-time updates locally and through a web interface. This personal project demonstrates a compact system that collects movement data, temperature, and activity status, and then displays this information on an OLED display and web UI for analysis.
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Movement Classification:
- Utilizes an accelerometer to measure and classify the cat’s activity (e.g., sleeping, walking, standing).
- Aggregates multiple samples over a two-second window to ensure stable readings.
- Computes pitch and roll from x, y, and z accelerations.
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Continuous Reporting:
- Reports time, temperature, and classified activity to a laptop for visualization.
- Data is displayed as strip charts on a web UI, allowing for easy interpretation of trends over time.
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Local OLED Display:
- Shows cat’s name, current activity, and the elapsed time in that activity.
- Features a button to cycle through different display modes (e.g., show name, show activity, show elapsed time).
- Implements text scrolling if necessary and uses I²C communication to drive the display.
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Temperature Measurement:
- Reads analog data from a thermistor-based temperature sensor.
- Converts raw ADC readings to engineering units (°F) using the Steinhart-Hart equation.
Accelerometer Task:
- Reads multiple acceleration samples within two seconds.
- Averages x, y, and z readings.
- Calculates pitch and roll, then classifies the cat’s activity.
- Synchronizes data with temperature and activity state before transmitting to the web interface.
Button Task:
- Detects button presses to switch between display modes.
- Enables toggling through cat name, activity, and elapsed time views on the OLED.
Display Task:
- Handles I²C communication to the OLED.
- Updates displayed information every cycle, showing relevant data (cat name, activity state, or time in activity).
- Manages scrolling text if the message exceeds the display size.
Temperature Task:
- Continuously reads from the ADC (A2 pin) for temperature measurements.
- Applies the Steinhart-Hart equation for accurate temperature conversion.
- Uses synchronization mechanisms (like semaphores) to ensure consistent console output and prevent race conditions.
Achievements:
- Successfully classified cat activities based on motion patterns.
- Achieved stable, continuous reporting of time, temperature, and behavior to a web UI.
- OLED display effectively presented data in a user-friendly manner.
Challenges:
- Fine-tuning the activity classification thresholds required iterative testing.
- Integrating the display updates with sensor tasks needed careful timing and resource management.
Potential Improvements:
- Display the current real-world time on the OLED rather than just elapsed time.
- Include a contact number or additional information on the OLED display for real-world utility, such as helping a lost cat return home.
- Optimize interrupt-driven input (for the button) to reduce polling and improve responsiveness.
Circuit diagram:
Images of circuit:
By integrating sensors, displays, and a web-based visualization platform, CatTrack provides a comprehensive system for monitoring feline behavior. This personal project underscores the potential for customizable pet monitoring solutions, offering insights into a cat’s daily activities and overall well-being.