Hardware

Nothing here is unusual. It is written down mostly so that the next repair does not start with an hour of tracing wires.

Mast and mounting

A 1.8 m aluminium tube clamped to an existing chimney bracket, guyed in two directions. The anemometer sits at the top, the shield about 40 cm below it and offset to the north so that the mast itself never shades the intake.

Enclosure

A grey polycarbonate box rated IP66, with the cable glands pointing down and a loop in every cable before it enters. The first winter taught us that the loop matters more than the gland: water walks along a straight cable and collects on the terminal block.

Power

A 10 W panel, a small MPPT charger and a 12 V LiFePO4 pack. Consumption averages under 90 mA, so the pack carries the station through roughly six overcast days. Mains is available on the roof but was deliberately not used — the logger should keep recording through an outage, which is exactly when the weather is interesting.

Logger

An ARM single-board computer with the sensor bus on I2C-1 and the rain and wind inputs on interrupt pins. The filesystem is mounted read-only apart from the data partition; after two corrupted cards that change alone ended the problem.