[masraum]

I never bought one of the units above, but I still want something. I just found another option. This option is wired and is what I was originally thinking about when I posted this thread. I discovered the info while looking into personal weather stations.

http://www.hobby-boards.com/catalog/index.php?cPath=22
Temp sensors can be bought from the same place for $18, combo temp/humidity for $52, barometric press for $60, rain gauge for $89, usb or serial adapter for $28, hubs for $50, etc....

http://www.hobby-boards.com/catalog/howto_basics.php

Firstly, let’s take a look at what 1-Wire is and what you can do with it. 1-Wire is really just a simple system of devices such as weather monitoring devices, garden monitoring devices, or home automation devices that are connected through a 1-Wire network to a computer (or other controller – more on that later). Your computer then receives signals from the devices, allowing you to track rainfall, temperature, humidity, soil moisture levels, lightning, and a host of other information.

So how does it work? Well, a 1-Wire network consists of a master controller which is connected to one or many slave devices. The master controller is typically a computer or microcontroller with an external 1-Wire interface such as our Serial Adaptor or USB Adaptor. All of the actual monitoring devices (lightning detector, moisture meter, motion detector, barometer, etc.) are slave devices. The master communicates with one or more slave device(s) using the serial 1-Wire protocol developed by Dallas Semiconductor, sending and receiving signals over a single data line plus ground reference. The 1-Wire protocol synchronizes the slave devices to the master. The master initiates and controls all activities on the 1-Wire network.

One key feature of the Dallas system is that every 1-Wire slave device has a guaranteed unique address that is realized as laser engraved on-chip ROM (Read Only Memory). This enables the master to individually recognize each of your slave devices, and means you can have multiple devices of the same type on the same network without conflict.

There are several pieces of software for various OS that will log/display the info from the sensors.

This looks like something that should be relatively inexpensive and that you can start and build on.