The avionics controller and the ship bridge

An avionics controller on a ship connects every peripheral on that ship to the wired network it sits on. Put a controller anywhere on the hull, connect it to a computer with a cable or a wired modem, and the computer sees the ship's sensors, propellers and engines as if each one had its own modem.

local alt = peripheral.wrap("ship_altitude_sensor_0")
local fwd = peripheral.wrap("ship_velocity_sensor_forward_0")
print(alt.getHeight(), fwd.getVelocity())

On the ground a controller bridges nothing.

What is bridged

Everything a wired modem could share is bridged: Avionics' own blocks, every Simulated and Aeronautics peripheral, and CC's generic peripherals such as chests, tanks, clutches and gearshifts. These are left out:

• Computers, turtles and modems. They network themselves; bridging them would loop the network or show a computer to itself.
• The controllers themselves, except once: the ship's controller appears as ship_avionics_controller, without a number, whichever controller publishes. It is the transponder switch, and that is ship-wide.
• Blocks tagged create_avionics:not_bridged. Shafts, cogwheels, gearboxes, encased shafts, chain drives, belts and chain conveyors: pure transmission, with nothing useful to ask and hundreds of them on a large ship. Packs can add to the tag.

The bridge rescans the ship every two seconds, and at once when a cable or modem next to a controller changes. Calls go straight to the block's own peripheral, so methods, units and mainThread behaviour are exactly what the peripheral's own page documents.

Names

Every bridged peripheral is named ship_<type>_<n>. The ship_ prefix keeps the names apart from the ones CC gives modem-shared peripherals, so a thermometer_0 on a modem and a ship_thermometer_0 on the bridge can coexist.

A block keeps its number for as long as it stays on the ship. Removing ship_thermometer_0 does not renumber ship_thermometer_1; the next thermometer placed takes the lowest free number. Names are saved with the controllers and survive restarts.

Names relative to the ship

Peripherals that measure in a direction are named by that direction in ship terms (see The bow):

Names by position

Propeller bearings, gyroscopic propeller bearings, adjustable burners, steam vents and portable engines (the create_avionics:named_by_position tag) are named by where they sit on the hull: _fore or _aft outside the middle third of the ship's length, then _port or _starboard off the centreline. A bearing on the centreline mid-ship has no suffix.

ship_propeller_bearing_aft_port_0
ship_propeller_bearing_aft_starboard_0
ship_propeller_bearing_0

A block keeps its position name when the hull grows around it, even if it would now fall in another zone; blocks placed later are zoned against the hull as it is then. When the bow changes, position names are worked out again, because fore, aft, port and starboard now mean other places.

The bow

A ship has one bow, shared by all its controllers. The first controller placed on a ship sets it to the way the controller faces; the arrow on top of every controller shows where the bow is.

To move the bow, hit a controller's side with a wrench. It turns a quarter and its new facing becomes the ship's bow. Names relative to the ship and position names follow straight away, so a script written for the old bow fails to find its peripherals instead of quietly steering the wrong way.

Several controllers

A ship can carry any number of controllers, for example one per computer room. They share one set of names: whichever computer you ask, ship_thermometer_0 is the same block. One controller (the one at the lowest position) publishes; the others stand by. If it is destroyed, the next takes over with the same names.

Transponder

The controller is also the ship's transponder. While it is on, a radar that hits the ship reports its name; while it is off, the ship shows up as an unidentified contact. The name is the ship's own name, or a six-letter code from its id when it has none.

Hit the controller's top (the antenna) with a wrench to switch the transponder, or use ship_avionics_controller from any computer on the ship:

local controller = peripheral.find("avionics_controller")
controller.setTransponder(false) -- radio silence

The switch is ship-wide: every controller on the ship shows the same state.

Radar Mk.1

The radar casts one narrow beam straight out of its face, twice a second, up to 256 blocks. It reports the first thing the beam meets: another ship, terrain, or obstructed when the radar's own ship is in the way. Contacts carry the distance and the closing speed (positive when approaching), and the name of a ship whose transponder is on. A comparator reads 15 right in front of the radar, falling to 1 at full range, and 0 for nothing or an obstructed beam.

There is no sweep: point the radar where you want to look, or put it on a bearing.