weewx: Installing from Scratch

These are generic instructions for installing weewx.

Prerequisites

Python

Python V2.5, V2.6, or V2.7 is required. Python V3.0 will not work.

Python Packages

Some python packages are required for the main weewx engine, and may be required for specific hardware configuration.

The weewx engine requires:

configobj (Version 4.5 or greater) Manages the configuration file weewx.conf.
Cheetah (Version 2.0 or greater) The templating engine.
Python Imaging Library (Version 1.1.6 or greater) Also known as PIL, this is included in many Python distributions.

To use MySQL as the database (instead of the default sqlite), you will also need (in addition to a MySQL server, of course):

MySQLdb for Python (Version 1.2.3 or greater). This is the Python DBAPI2 adapter for MySQL.

There is one optional package:

pyephem (Version V3.7.3 or greater). For extended almanac information. If not installed, fallback information will be used.

Some stations require a serial and/or USB package:

pyusb (Version 0.4 or greater). Driver for USB.
pyserial (Version 2.3 or greater) Driver for a serial connection.

Time

The time on the VantagePro is automatically synchronized with the weewx server nominally every four hours (changeable by the user). You should run a NTP daemon on your server to insure that it is synchronized with the correct time. Doing so will greatly reduce errors, especially if you send data to services such as the Weather Underground.

System requirements

I run weewx on a 500MHz system with an AMD Geode processor and 512 MB of memory. Configured this way, it consumes about 5% of the CPU and about 50MB of total memory.

Downloading

The weewx software can be downloaded from SourceForge at http://sourceforge.net/projects/weewx/files

Installing

weewx is "Pure Python", which means that is 100% Python with no modules to compile. It uses the standard Python distutils install method, which is very easy and flexible.

Unpacking

Start by unpacking the archive (substitute your version for X.Y.Z) into any convenient directory where you have write permission

tar xvf weewx-X.Y.Z.tar.gz

Then change directory into it:

cd weewx-X.Y.Z

Choosing where to install

The next step is to figure out where you want to install weewx. $WEEWX_INSTALL represents the location where the root weewx directory will be installed. By default, this location is /home/weewx. However, it can be changed by editing the file setup.cfg and changing the following line

home = /home/weewx

The nominal directory layout will be:

$WEEWX_INSTALL/bin	Python packages and scripts
$WEEWX_INSTALL/weewx.conf	Configuration file
$WEEWX_INSTALL/skins	Template skins and their configuration files
$WEEWX_INSTALL/archive	sqlite3 archive and statistical databases
$WEEWX_INSTALL/public_html	Generated HTML and .PNG images

Build and Install

Build the distribution

./setup.py build

Because weewx is pure Python this doesn't compile anything, but it does arrange files for the final installation

Then install it. If you have write permission in the directory where weewx will go, then type

./setup.py install

Otherwise, if you do not have write permission, you will have to use sudo:

sudo ./setup.py install

Permissions

Strictly speaking it is not necessary to install or run weewx with root privileges. You only need read/write access to the serial port for your hardware. For example, if your hardware has a USB interface /dev/ttyUSB0

sudo chmod a+rw /dev/ttyUSB0

If you install into a directory where you have write permissions, you can install and run weewx without root privileges.

Upgrading

Before upgrading from a previous version of weewx, check the Upgrade Guide to see if there any specific actions required.

Then follow the 'Build and Install' procedure above.

Warning!
Before starting an upgrade, be sure to set home in the file setup.cfg.

The build and install process will do the following for you:

Save the old bin directory as $WEEWX_INSTALL/bin.YYYYMMDDHHMMSS where YYYYMMDDHHMMSS is a timestamp
Install the new version in the bin directory, while preserving any user extensions in the bin/user directory
Save a copy of the old weewx.conf as $WEEWX_INSTALL/weewx.conf.YYYYMMDDHHMMSS
Merge any changes made to the old configuration file weewx.conf into the new configuration file, then install the merged copy. This effectively causes any changes to override the values in the new version of weewx.conf
Install a skins directory if one does not already exist.