Ultrasonic Anemometer Project

A complete 2D ultrasonic wind speed and direction measurement system with wireless data transmission and statistical analysis capabilities.

Project Overview

This project implements a sonic anemometer that measures wind speed and direction using ultrasonic transducers. The system consists of three main components:

1. Anemometer Device - Arduino-based sensor that calculates wind measurements.
2. WiFi Module - ESP32-based wireless transmission system.
3. Data Collection & Analysis - Python scripts for data gathering and statistical analysis.
4. CAD - CAD Files for initial designs for 3D anemometer, and completed 2D anemometer. Along with the designs and laser-cut drawings for the model.

System Architecture

[Ultrasonic Signal Board] → [Arduino Uno] → [Serial] → [ESP32] → [MQTT] → [Python Data Collector]
                                    ↓
                            [7-Segment Display]

Hardware Requirements

Anemometer Components

• Arduino Uno
• 3x Ultrasonic RX transducers (North, East, West)
• 1x Ultrasonic TX transducer
• 4-digit 7-segment display (common cathode)
• Various electronic components
• PCB

WiFi Module Components

• ESP32 development board (ESP32-S3-DevKitC-1)
• Serial connection to anemometer Arduino

Additional Components

• 9V Wall Wart with power pigtails
• Enclosure/mounting hardware (see CAD folder)

Software Requirements

• PlatformIO (recommended) or Arduino IDE
• Python 3.7+ with packages:
  • paho-mqtt
  • pandas
  • numpy
  • statsmodels
  • scipy

Quick Start Guide

1. Hardware Setup

NOTE: Please see Instructable for help in assembly.

1. Build the anemometer circuit following the pin configurations in anemometer/src/main.cpp
2. Connect ultrasonic transducers
3. Wire the 7-segment display to digital pins 2-13
4. Connect Arduino to ESP32 via serial (9600 baud)

2. Software Installation

1. Install PlatformIO in VS Code
2. Clone this repository
3. Install Python dependencies:

   pip install paho-mqtt pandas numpy statsmodels scipy

3. Configuration

1. Create arduino_secrets.h in WiFi_Module/include/ with your credentials:

   #define SECRET_SSID "your_wifi_ssid"
   #define SECRET_PASS "your_wifi_password"
   #define SECRET_MQTTUSER "your_mqtt_username"
   #define SECRET_MQTTPASS "your_mqtt_password"

4. Upload Code

1. Upload anemometer code to Arduino Micro/Uno
2. Upload WiFi_Module code to ESP32

5. Data Collection

1. Run the MQTT collector:

   cd data_collector
   python mqtt_collector.py

2. Follow prompts to collect 200 readings
3. Use merger.py to combine multiple CSV files
4. Run analysis.py for statistical analysis

Calibration

The anemometer requires calibration in three conditions:

1. Still air (calm conditions)
2. Known north wind (9 m/s reference)
3. Known east wind (9 m/s reference)

Update the calibration values in anemometer/src/main.cpp:

const Wind_t calm =   {547, 581}; // Still air readings
const Wind_t north =  {850, 226}; // North wind readings  
const Wind_t east =   {720, 712}; // East wind readings

Data Format

The system outputs JSON-formatted wind data:

{"speed": 5.50, "direction": 126}

Where:

• speed: Wind speed in m/s
• direction: Wind direction in degrees (0-360°, meteorological convention)

Folder Structure

├── anemometer/          # Arduino code for wind calculations
│   ├── src/main.cpp     # Main anemometer logic
│   ├── lib/sevSeg/      # 7-segment display library
│   └── platformio.ini   # Build configuration
├── WiFi_Module/         # ESP32 WiFi transmission code
│   ├── src/main.cpp     # MQTT publishing logic
│   └── platformio.ini   # ESP32 build configuration
├── data_collector/      # Python data collection tools
│   ├── mqtt_collector.py   # MQTT data collection script
│   ├── merger.py           # CSV file merger utility
│   └── analysis.py         # Statistical analysis tools
└── CAD/                 # 3D models and mechanical designs
    ├── Device             # STL files to print 2D Anemometer
    └── Exhibit            # Mix of STL and DXF files to make scaled

Detailed Documentation

Each folder contains its own README with specific setup instructions:

• Anemometer README - Arduino setup and calibration
• WiFi Module README - ESP32 configuration and MQTT setup
• Data Collector README - Python tools and analysis

Troubleshooting

Common Issues

No MQTT data received:

• Check WiFi credentials in arduino_secrets.h
• Verify MQTT broker connectivity
• Ensure serial connection between Arduino and ESP32

Incorrect wind measurements:

• Recalibrate sensors in known conditions
• Check transducer positioning (East/West alignment)
• Verify analog pin connections

7-segment display not working:

• Check pin connections match code configuration
• Verify common cathode display type
• Test with simple digit display first

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test with hardware setup
5. Submit a pull request

License

This project is open source. See individual files for specific licensing information.

Acknowledgments

This project uses:

• PlatformIO for embedded development
• PubSubClient library for MQTT communication
• ArduinoJson for data formatting
• Python scientific stack for data analysis
• Claude Sonnet 4 was used in the following capacities on the Python scripts:
  • Merging CSV files
  • Cleaning up the output of scripts
  • Conducting ANOVA tests

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For detailed component-specific instructions, see the README files in each subfolder.