Backyard Meteorological Instrumentation

Shelter Internal Layout

The Main equipment shelter was originally designed for electric gate control. The box has been bolted to two (2) 50mm x 50mm x 1800mm fence posts using 12mm bolts. The posts are being being set into the ground to a depth of 400mm and the base reinforced with concrete. Once concrete is poured in, it will be about a week before the concrete reaches its maximum strength, although this not considered to be critical, since there should be minimal issues with wind resistance as it is mounted near the corner of two tall fences with trees and structures on the other side of the fences.

The image below shows the initial development installation. The Raspberry Pi is connect to the home LAN and can be controlled using SSH or VNC from anywhere on the network. Cable forming will be carried out after the remaining hardware is made and installed.

There are four (4) DIN rails in the enclosure. The bottom three (3) sections of rail are recovered items and are not the correct width for this project. If space becomes an issue the second and third rails from the bottom will be replaced with wider sections, although due to the external cables which terminate at the left had side of these rails, the  space gained will be limited on that side.

The rails have the following general functions:

(1) Bottom Rail. Terminal strips for cables that enter and leave the enclosure via the conduit holes in the base of the enclosure.

(2) Second Bottom Rail. This rail holds the Raspberry Pi 4, its I/O terminal block, and the power supply that provides +5V to the Pi and a +12V supply that will be used by other sensors.

(3) Third Bottom Rail. This rail holds the Software Defined Radio (SDR), internal sensors such as the barometric pressure sensor and the second power supply which provides +5V and +3,3V for sensors.

(4) Top Rail. The top rail is reserved for line drivers and other sensors that may be added later.
The Enclosure has four (4) holes in the bottom to allow for the entry and exit of cables to the enclosure via conduits. At this stage, the holes (looking from the front) will be used as follows:

(1) First (Right Hand) Hole. This hole is connected to the conduit that runs between the shed and the enclosure and contains four (4) cables. Cable 1 contains the +24V supply and its Earth wire. Cables 2 & 3 are the Ethernet cables that connect to the Local Area Network (LAN). Cable 4 is the six (6) wire status cable that runs back into the shed where it can be connected to another status cable that runs back to the house.

(2) Second Hole. This hole will be used for the cables connecting the enclosure to the local sensors.

(3) Third Hole. This hole will be used for cables connecting the enclosure to local sensors and any radio antennas.

(4) Fourth (Left Hand) Hole. This hole will be used for the power and communications cable that will connect to the second enclosure (if it is installed).

While the cables using the send and third holes will go to sensors mounted on the top of the enclosure's posts, the power and communications cables from the shed will be run underground in a conduit.

If there are power and communication cables to the second site via the fourth hole, they will also  be run underground in conduit.

Shelter External Layout

Additional mounting points are required for sensors that need to be mounted externally. To provide a convenient mounting bar, a beam will be mounted horizontally across the two (2) posts on which the enclosure is mounted.

Licenced under Creative Commons Attribution Share Alike 4.0 International or better by Mark Little (2022 - 2023)