PicoW-Mood-Tracker: OOP-based IoT Logger

IoT mood tracking system built with Raspberry Pi Pico W. This project demonstrates the integration of hardware sensors, local data persistence, and cloud synchronization using an Object-Oriented Programming (OOP) approach.

0. Introduction

There are hundreds of mood-tracking apps out there, but let’s be honest: finding your phone, unlocking it, and navigating through menus just to log a feeling is tedious. I wanted something simpler—a physical device where a single "Click" does it all. As a Python learner only a few months into the journey, I was starting to get bored with results that only lived on a computer monitor. I needed something tactile. If you are a fellow beginner starting to feel the "Python slump," I hope this project serves as a refreshing break and reminds you how much fun coding can be when it interacts with the real world.

Real-time mood logs as seen on the mobile Google Sheets app. You can monitor your emotional trends directly from your smartphone using the Google Sheets app, anywhere and anytime.

1. Key Features

• OOP Architecture: Modular design with dedicated managers for Display, WiFi, Logging, and Cloud Uploading.
• Hardware Integration: Real-time feedback via SH1106 OLED and precise timekeeping with DS3231 RTC.
• Data Resilience: Local CSV logging ensures no data loss during network outages.
• Cloud Sync: Seamless data transmission to Google Sheets via REST API.
• Reliability: Memory management and hardware debouncing for stable long-term operation.

2. Tech Stack

• Language: MicroPython
• Hardware: Raspberry Pi Pico W, SH1106 OLED, DS3231 RTC, Tactile Buttons
• Cloud: Google Apps Script (Web App)

💡 Wiring Guide & Tips

To ensure a stable connection and prevent hardware damage, please follow these guidelines:

General Wiring Tips

• I2C Sharing: Both the OLED display and the RTC module use the I2C protocol. You can connect both SDA and SCL lines to the same GPIO pins on the Pico W.
• Power Check: Double-check the VCC (3.3V) and GND pins before powering on. Reversing these can permanently damage your sensors.
• Bus Line Strategy: If possible, use the long power rails (side strips) on the breadboard as dedicated "Bus Lines" for VCC, GND, SDA, and SCL for easier management.

Button Connection (Tactile Switch)

• Diagonal Wiring: For 4-pin tactile buttons, it is highly recommended to connect the GPIO wire and GND wire to pins located diagonally from each other. This ensures a stable connection regardless of the internal switch structure.
• Pull-up Resistor: This project uses internal pull-up resistors (Pin.PULL_UP), so you only need to connect one side of the button to the GPIO and the other to GND.

Tip for Hobbyists

• Using different colored wires (e.g., Red for VCC, Black for GND, Yellow for SCL, Blue for SDA) makes debugging significantly easier when something goes wrong!

3. Project Journey: From Script to System

This project evolved through a rigorous refactoring process. (1) Monolithic Script: Initial proof-of-concept. (2) Refactoring (OOP): Transitioned to class-based design for better encapsulation. (3) Modularization: Decoupled components into 5 distinct modules for professional maintenance and scalability.

4. Project Structure

• main.py : Must be saved directly to Pico.
• lib/ : Containing functional modules.
  • display_manager.py : Handles I2C for SH1106 OLED & DS3231 RTC.
  • wifi_manager.py : Manage Pico W's wireless connectivity.
  • local_logger.py : Provides persistent CSV logging (offline storage).
  • google_uploader.py : Syncs data with Google Sheets API.
  • sh1106.py : MicroPython Driver for OLED. (See below 7. Credits & Acknowledgments)
  • ds3231.py : Lightweight RTC Driver focused on I2C communication and BCD-decimal conversion.
• images/ : Contain hardware schematics and project photos.
• secrets_template.py : Template for environment variables (wifi / API).

5. How to Install & Run

This project uses Thonny IDE to upload and run code on the Raspberry Pi Pico W.

1) Prerequisites

• Install Thonny IDE.
• Connect your Pico W to your computer via USB.
• Ensure MicroPython firmware is installed on your Pico W.

2) Setup Secrets

1. Locate secrets_template.py in this repository.
2. Rename it to secrets.py.
3. Open secrets.py and enter your WiFi SSID, Password, and your Google Apps Script URL.

3) Upload Files to Pico W

1. Open Thonny IDE.
2. Go to File > Open... and select all files from the lib/ folder and the main.py file from your local machine.
3. For each file, go to File > Save as... and select Raspberry Pi Pico.
4. Important: * Save the contents of the lib/ folder (e.g., display_manager.py, wifi_manager.py, etc.) into a folder named lib on the Pico.
   • Save main.py and secrets.py directly in the root directory of the Pico.
   • Don't forget to include hardware drivers.

4) Run

1. Disconnect and reconnect the USB, or simply press the Run button in Thonny.
2. Your Pico W will now start tracking your mood!

6. Security Note

secrets.py (containing WiFi credentials and Google API URLs) is excluded from this repository for security reasons. Please use secrets_template.py as a reference.

7. Credits & Acknowledgments

This project utilizes a combination of open-source libraries and custom-built drivers:

• SH1106 MicroPython Driver: Created by Radomir Dopieralski, Robert Hammelrath, and Tim Weber.
  • Original Repository: robert-hh/SH1106
  • License: MIT License
• DS3231 Custom Driver: Personally developed for this project, focusing on lightweight I2C communication and BCD-decimal conversion for RTC management.

Special thanks to the open-source contributors whose work made this DIY project possible.