Union College Weather Station

1. Union College Weather Station Greg Mahlum Advisor: Dean Traver

2. Goals • Design and Implement a weather station for Union College • The goals include: • Website • Current conditions • Easy access to weather data database • Reliable collection of weather data • Record usable amount of data for study

3. Overview • Sensors on roof of North Wing S&E where weather data can be collected • Microcontroller reads data from sensors • Data sent to a server via Serial Device Server • Server archives data in a database using MySQL and hosts a website using Apache • Scripts used to constantly obtain and archive data • Current and archived data available on website

4. Subsystems • Microcontroller & Sensors • Enclosure • Communication Link • Server • Database • Website

5. Background • Jeffery D’Alessandro and Brian Kruppenbacker started project for their senior project in 2005 • Microcontroller & Sensors • Replaced humidity sensor • New humidity sensor shorted out • Enclosure • Added braces to stabilize arm supporting UV sensor in order to reduce vibrations due to machinery on the floor below

6. Communication • Serial to Ethernet communication using a Moxa serial device server • Wide temperature model needed due to cold temperatures in the winter • Uses protocol developed by previous group • RS-232 • 9600 baud, 8 data bits, 1 stop bit, no parity • Uses cyclic redundancy check for error detection

7. Server • Current server used for development • Programs and scripts will be moved to a server that gets routine maintenance once development is completed • Until development is finished the old Robot Club computer used as server • Dell Dimension 8200 • 6 years old • 40 GB Hard Drive • Partitioned Hard Drive into three parts • 10 GB for system files • 1 GB for swap space • Everything else (~27 GB) for weather data

8. OS • Fedora 7 original OS • Compatibility issues with serial device server drivers • Issues must be resolved before project can be moved to a maintained server • Fedora Core 5 • Current OS of development server

9. Database • Used MySQL for database managment • Two tables used to keep track of data • Past hour • Keeps track of the weather in the past hour • Every hour data currently in table is averaged, the result is added to the archived weather table • Archived weather • Biggest table, contains one entry for every hour

10. Website • http://weather.union.edu • Apache used for web server program • Display current weather conditions • Temperature • Humidity • Pressure • Precipitation • UV index • Wind direction and speed • Dew point • Wind chill • Heat index • Allow users to view archived weather • Users able to select specific periods of time • Data is pulled from database using built in functions in php

11. Data Collection • Sample as frequently as possible • Readings received every 9-10sec • Each reading archived in past hour table • Averages taken every hour • Result placed in archived weather table • Frequency of averaging can be adjusted using crontab

12. Testing & Monitoring for Accuracy • Used Geology Department station and weather.com to visually compare data • Initial inspections • Temperature readings on average 14% higher than geology department readings • Pressure consistently 4% lower • UV readings never exceed 1.0 • Need to inspect data at each point in the system to find where errors may be • Voltage output from sensor • Digital conversion from microcontroller • Calculation on server

13. Thanks • Dean Traver • Professor Spallholtz • Frank Tricozzi • Aaron Lagasse

14. Questions?