WeatherLink Data to CSV

Format and log new WeatherLink data to a local CSV file.

Purpose

1. WeatherLink only stores a fixed amount of archive data for each station, so you are guaranteed to lose data eventually if you do not back it up. For example, my account holds up to 10240 records; a new record is added every 30 minutes, so it can only keep the most recent 213 days worth of data.
2. On the web service, data is stored in 52 byte records with a lot of unnecessary data (e.g. soil temperature and leaf wetness are useless if you do not have the right equipment on your weather station). This program formats and stores just the data you want in a CSV.

Setup

Two files are needed for the program to function:

1. A .weatherlink file in your home directory with your weatherlink.com account name on the first line, password on the second line, and a comma-separated list of fields that you want to exclude from the CSV (on as many additional lines as needed). A list of all of the field names is in the progdata.py file. Your dotfile might look like this:

ACCOUNT
PASSWORD
soil_moist1, soil_moist2, soil_moist3, soil_moist4

2. A CSV file. By default, the program expects weatherlink.csv in your home directory -- simply create an empty file. You can use f FILENAME or --file=FILENAME as an argment to specify a different file.

Note: designed for data format Rev "B" (which is used in Davis firmware dated after 4/24/02). Support for older firmware may be added in the future.

Data Format

Check out explanations of each field of the data format (Rev "B") in the manufacturer's PDF.

Field	Offset	Size	Dash Val
Date Stamp	0	2	N/A
Time Stamp	2	2	N/A
Outside Temperature	4	2	32767
High Out Temperature	6	2	-32768
Low Out Temperature	8	2	32767
Rainfall	10	2	0
High Rain Rate	12	2	0
Barometer	14	2	0
Solar Radiation	16	2	32767
Number of Wind Samples	18	2	0
Inside Temperature	20	2	32767
Inside Humidity	22	1	255
Outside Humidity	23	1	255
Average Wind Speed	24	1	255
High Wind Speed	25	1	0
Direction of Hi Wind Speed	26	1	255
Prevailing Wind Direction	27	1	255
Average UV Index	28	1	255
ET	29	1	0
High Solar Radiation	30	2	0
High UV Index	32	1	0
Forecast Rule	33	1	193
Leaf Temperature	34	2	255
Leaf Wetnesses	36	2	255
Soil Temperatures	38	4	255
Download Record Type	42	1	N/A
Extra Humidities	43	2	255
Extra Temperatures	45	3	32767 (typo?)
Soil Moistures	48	4	255