Datasheet
1.3 Original Davis data loggers
Data loggers cover two different functions: archiving data from the console and provid-
ing a means of communicating with the console from a computer.
The data logger itself contains only a very limited amount of logic: it is mainly made
up of an Adesto Technologies DataFlash chip for data storage and a level converter
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used
for converting the 3.3V signals from the console’s in-system UART
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to more commonly
accepted signals levels — and the other way around, providing safe 3.3V signal levels to
the ATmega128L microcontroller (MCU) found on the main printed circuit board (PCB)
of the console. Apart from that, the data logger doesn’t do much. And even better, it
is fully controlled by the ATmega128L MCU in the console — the data logger just sits
quietly around, doing what it’s told to do.
Original Davis data loggers are delivered with the WeatherLink software, a 1990-ish
software product which won’t leave a lasting impression with anyone. The RS-232
version of the data logger (product # 06510 SER) has a MSRP of $165 as listed on the
Davis website and product catalog [1], somewhat unreasonable for a product made
up of the following parts — even after the cost of R&D efforts has been taken into
consideration:
• The PCB containing the circuit (internally named VantageLINK).
• 2 diodes.
• 3 resistors.
• 8 capacitators.
• 1 Adesto Technologies AT45DB011 DataFlash chip.
• The interface unit (RS-232/serial line level converter, USB interface, ...).
The actual interface components are version dependent.
• The 20-pin console connector.
• The voltage regulator (Seiko S-81230) may be a left-over from a different Davis
product line — the power supply is regulated at 3.0 V, not 3.3 V.
• Exquisite plastic molding, reportedly injection-molded by Lionel Lau, Taiwan.
Apart from the price tag, another well-known issue with the original Davis data
loggers is the amount of heat they produce. Poor thermal design causes the internal
temperature sensor in the console to over-read when an original data logger is attached
to the console, resulting in erroneous indoor temperature readings.
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Or other converter, as appropriate for the data logger variant in question.
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Universal Asynchronous Receiver/Transmitter.
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