Datasheet

1 Introduction

1.1 The Davis Vantage Pro2 series

Despite shortcomings in sensor accurancy

the Vantage Pro2 series of weather stations,

manufactured by Davis Instrument Corp. of Hayward, CA, USA (from here on referred

to as Davis) have been popular with weather hobbyists for several years. While neither

build quality nor sensor accurancy are the best, there is an abundant range of product

add-ons available — not necessarily having a true or perceived value anywhere near

the MSRPs, but still useful for self-education, local climate monitoring and carrying

out general weather observations. For educational use, the Davis series of weather sta-

tions often ﬁt the bill nicely (again, somewhat over-priced — but acceptable), allowing

students to gain hands-on experience in environmental data collection, data extraction

and data analysis.

One of the main advantages of the Davis VP2 series of weather stations has been

the availability of a serial line for access to weather data without resorting to expensive

add-ons such as the original Davis data loggers. In the educational sector, where each

dime is counted at least twice before it is spent, this aspect is indeed of great importance

— possibly even more important than the somewhat questionable sensor accurancy.

1.2 Typical station setup

A typical Davis weather station setup includes the individual outdoor and/or indoor

sensors, a connector box commonly referred to as the ISS

— possibly combined with a

radio transmitter, depending on station version — and the indoor display unit referred

to as the console. Several consoles can receive data from one single ISS box.

The console receives data from the ISS, performs some basic calculations, stores

min/max values and calculates derived values. Depending on station conﬁguration, it

also performs a number of other tasks, including alarm output (sensor readings above

or below preset alarm thresholds), acting as a repeater between the ISS and another

console, and sending data to an attached data logger for storage/retrieval. The console

also processes and replies to commands received via its serial line. These commands

are typically issued by software

running on an attached computer — requesting data

from the console.

Interestingly, Davis documentation [2] states that using the serial line for communi-

cation with the outside world ”requires a WeatherLink with Standard Data Logger”. As is

now widely known, this statement is far from correct.

Mainly due to low-cost environmental sensors — signiﬁcant improvements could have been achieved

by using only marginally more expensive parts.

Integrated Sensor Suite

WeatherLink, Weather Display, WOSPi, weewx, etc.

http://meteo.annoyingdesigns.com 2