This guide provides complete instructions for installing, configuring, and operating the Weather Station Telemetry System. The system is designed for educational purposes and demonstrates professional-grade embedded systems engineering principles suitable for aerospace and IoT applications.
Essential Components:
Optional Components:
Development Environment:
Required Libraries:
Computer Specifications:
Begin by downloading and installing the Arduino IDE from the official Arduino website. This integrated development environment provides all the tools necessary for compiling and uploading code to your Arduino board. During installation, ensure that you allow the installer to install USB drivers, as these are essential for communication between your computer and the Arduino.
After installation, launch the Arduino IDE and navigate to the Library Manager by selecting Sketch > Include Library > Manage Libraries from the menu. In the search box, type “DHT sensor library” and locate the library published by Adafruit. Install this library along with its dependency, the Adafruit Unified Sensor library. These libraries provide the essential functions for interfacing with the DHT22 sensor and handling its data output.
Power and Ground Connections: Connect the DHT22 sensor’s VCC pin to the 5V rail on your Arduino Uno. This provides the necessary operating voltage for the sensor. Connect the GND pin of the DHT22 to any ground pin on the Arduino to complete the power circuit. Ensure these connections are secure, as loose power connections can cause intermittent failures that are difficult to diagnose.
Data Connection: Connect the data output pin of the DHT22 sensor to digital pin 2 on the Arduino Uno. This pin assignment matches the configuration defined in the software and enables the Arduino to receive sensor readings. Double-check this connection, as an incorrect pin assignment will prevent the system from reading sensor data.
Connection Verification: Before proceeding, verify all connections match the following configuration:
Download the complete project from the GitHub repository and extract all files to a dedicated project folder on your computer. Open the Arduino IDE and navigate to File > Open, then select the mainWeatherStation.ino file from your project folder. The Arduino IDE should automatically load all associated module files as tabs within the project.
Before uploading the code, verify that your Arduino Uno is properly connected and recognized by your computer. In the Arduino IDE, select Tools > Board and ensure “Arduino Uno” is selected. Then choose Tools > Port and select the port corresponding to your Arduino connection (this will typically show as COM port on Windows or /dev/ttyUSB or /dev/ttyACM on Linux).
Compile the project by clicking the verify button (checkmark icon) in the Arduino IDE toolbar. This process checks your code for syntax errors and ensures all required libraries are properly installed. If compilation errors occur, verify that you have installed the required DHT sensor libraries as described in Step 1.
Upload the compiled code to your Arduino by clicking the upload button (right arrow icon). During upload, you should see LED indicators on the Arduino board flashing, indicating that data transfer is occurring. The process typically takes 30-60 seconds depending on your computer’s performance.
When power is first applied to the system, either through USB connection or external power supply, the Arduino begins executing the initialization sequence. This process includes several critical steps that establish system reliability and prepare for normal operation.
The communication module initializes first, establishing the serial connection at 9600 baud rate and performing initial health checks. You can monitor this process by opening the Serial Monitor in the Arduino IDE (Tools > Serial Monitor) and setting the baud rate to 9600. During successful initialization, you should see confirmation messages indicating that communication has been established.
Following communication setup, the sensor module attempts initialization with automatic retry logic. The system will make up to five attempts to establish communication with the DHT22 sensor, with brief delays between attempts to allow for sensor stabilization. Successful sensor initialization will be confirmed through status messages in the Serial Monitor.
During normal operation, the system transmits telemetry data every 30 seconds in structured JSON format. Each message includes timestamp information, sequential message numbering, sensor identification, measured values, and success status indicators. This comprehensive data structure enables thorough analysis of system performance and data quality.
Between data transmission cycles, the system performs communication health checks every 15 seconds using a ping-pong protocol. These health checks verify that bidirectional communication remains functional, ensuring that the system can receive commands from the ground station in addition to transmitting sensor data.
Monitor system operation through the Serial Monitor, where you should observe regular telemetry messages and occasional health check confirmations. Normal operation produces steady, predictable message patterns with minimal timing variation.
Sensor Data Messages:
{
"timestamp": 1234567,
"id": 42,
"type": "sensor_data",
"sensor_type": "temperature",
"value": 23.5,
"success": true
}
Health Check Messages:
ping
(System expects “pong” response for successful health verification)
Symptom: No output in Serial Monitor Potential Causes: Incorrect baud rate setting, loose USB connection, wrong COM port selection Resolution: Verify Serial Monitor baud rate is set to 9600, check USB cable connection, confirm correct port selection in Arduino IDE Tools menu
Symptom: Garbled or corrupted text in Serial Monitor
Potential Causes: Baud rate mismatch, electrical interference, power supply instability
Resolution: Reset Arduino board, verify 9600 baud rate setting, check power supply connections for security
Symptom: Sensor readings show as “NaN” or error messages Potential Causes: Loose data connection, defective DHT22 sensor, incorrect pin assignment Resolution: Verify data pin connection to Arduino pin 2, check DHT22 power connections, consider sensor replacement if problems persist
Symptom: Readings outside expected ranges Potential Causes: Sensor calibration drift, environmental factors, electrical interference Resolution: Verify sensor is not exposed to extreme conditions, check for nearby sources of electrical interference, consider sensor recalibration or replacement
Symptom: Irregular timing between messages Potential Causes: Processing delays, communication timeouts, power supply variations Resolution: Monitor for error messages indicating specific failures, verify stable power supply, check for environmental factors affecting sensor response time
Symptom: Frequent initialization failures Potential Causes: Marginal power supply, sensor hardware issues, electromagnetic interference Resolution: Verify adequate power supply capacity, test with different DHT22 sensor unit, relocate system away from potential interference sources
The default measurement interval of 30 seconds provides reliable operation while conserving system resources. This timing can be modified by changing the comparison value in the main program loop from 30000 milliseconds to your desired interval. However, consider that the DHT22 sensor requires approximately 2 seconds between readings for stable operation.
Default validation ranges are set for typical indoor environments (-50°C to +60°C for temperature, 0% to 100% for humidity). These ranges can be adjusted in the sensor module by modifying the temperatureMinRange, temperatureMaxRange, humidityMinRange, and humidityMaxRange constants to match your specific application requirements.
The current JSON format prioritizes readability and debugging ease during development and educational use. For bandwidth-critical applications, the system architecture supports migration to binary protocols by modifying only the communication module, leaving sensor and coordination logic unchanged.
The Serial Monitor provides immediate visibility into system operation and data quality. For extended monitoring sessions, consider using serial terminal applications that support data logging to files for later analysis.
JSON message format facilitates easy import into data analysis tools, spreadsheet applications, and databases. The structured format includes all necessary metadata for comprehensive analysis of sensor performance, timing accuracy, and system reliability.
The standardized JSON output format enables integration with IoT platforms, databases, and web services. Consider implementing data bridges or middleware applications to connect the telemetry system with larger monitoring infrastructure.
Periodically verify connection integrity, especially if the system experiences mechanical vibration or temperature cycling. Clean sensor housing to prevent dust accumulation that could affect measurement accuracy. Monitor system performance trends to identify gradual degradation before it affects data quality.
For extended unattended operation, consider implementing watchdog timer functionality and automatic system restart capabilities. Plan for sensor calibration verification against known reference standards at regular intervals to maintain measurement accuracy.
Ensure proper electrical safety practices during installation and maintenance. When operating in outdoor environments, provide appropriate weatherproof protection for electronic components while maintaining sensor exposure to environmental conditions.
This user guide provides comprehensive instructions for successful installation and operation of the Weather Station Telemetry System, enabling effective use for educational and research applications.