Datasheet
What does it take to build a third-party data logger?
A little effort. Study the datasheets for the relevant components and you’ll find that bits
and pieces fit together quite nicely. Section 6.2 refers. Or use a Raspberry Pi, a BeagleBone
or another minicomputer which can be configured to meet your exact needs.
What’s the main purpose of this document?
Self-education. And, of course, to aid others in obtaining access to the serial line of
their crippled Davis console — without spending $165 on a data logger which will only
cause erroneous indoor temperature readings.
Also — hopefully — someone at Davis will realize how one single management
decision aids in tearing apart the company’s reputation.
Where can I get a pre-programmed ATtiny25/45/85 as described in this document?
Get in touch with the author, who may have some at hand for $25, including worldwide
airmail shipping. Payments are accepted via PayPal. Please note the previous question,
though — this is not a business undertaking
14
, only ”users helping users”.
Please specify whether you prefer the ”fixed ID” (section 4.3) or the ”random ID”
(section 4.4) variant. Also note that all in-house tests of the ”random ID” variant have
been successful — still there is no guarantee that all permutations generated will au-
thenticate with the VP2/Vue consoles. If authentication fails, simply remove all power
from the console and try again.
Can the serial line be used for a firmware upgrade?
Yes, that’s indeed one of the purposes of the serial line. Several consoles have been
upgraded from firmware version 1.90 to version 3.12 and from version 3.00 to version
3.12. You only need the GND, TXD and RXD lines. No data logger is required, as long
as the serial line has been unlocked.
14
The author already has a daytime job — and he is not running a charity, so if you don’t want to go
through the process of programming the ATtiny25/45/85 yourself, you can pay a few dollars for the parts,
shipping and trouble caused. That’s just fair, isn’t it?
http://meteo.annoyingdesigns.com 35