LAN and WiFi

LAN and WiFi networks are groups of connected entities that send and receive signals consisting of key:value pairs. Keys may be any text string, including internal item names. Values are integers.

Control Panels form LANs

Control Panels can be manually linked by cables to form a LAN. Cables may be up to 10m long, and pass under other entities.

WiFi Towers form WiFi meshes

WiFi Towers automatically link up with other towers and panels within a 30m radius.

Control Panels run Lua

Control Panels can run Lua scripts which may:

• Monitor and control adjacent entities
• Send and receive on LAN and WiFi networks, if connected
• Define custom input fields in the entity popup window
• Change the color of the panel to indicate status or activity

Lua scripts supply two entry points:

• function main() called each tick
• gui = {...} to declare custom input fields

Lua scripts included

Several Lua scripts are included, ready to go, no custom scripting required. Of course if you like scripting and modding, go nuts.

Example of a customizable constant signal generator: 

gui = {
  title = "Constant signal",
  description = "Broadcast a steady signal to a network",
  fields = {
    network = {
      title = "Network",
      type = "string",
      options = {
        lan = "LAN",
        wifi = "Wifi",
      },
      description = "The target network to receive signals",
      default = "lan",
      order = "a",
    },
    key = {
      title = "Name",
      type = "string",
      description = "Name of signal to broadcast",
      default = "",
      order = "b",
    },
    val = {
      title = "Value",
      type = "integer",
      description = "Value of signal to broadcast",
      default = 1,
      order = "c",
    },
    log = {
      title = "Log Activity",
      type = "boolean",
      description = "Periodically log activity to console",
      default = true,
      order = "d",
    },
  }
}
 
function main()
  local fields = api.gui_fields()
  local good_signal = fields.key ~= ""
 
  if not good_signal then
    print("waiting for signal name")
    api.color(api.colors.warn)
    api.sleep(api.ups())
    return
  end
 
  api.color(api.colors.ok)
 
  -- activity log
  if api.tick() % api.ups() == 0 and fields.log then
    print("current signal: "
      .. fields.key .. ":" .. fields.val)
  end
 
  local send = fields.network == "lan"
    and api.lan_send or api.wifi_send
  send(fields.key, fields.val)
end

The corresponding UI that generates:

Complex networks

Complex networks are possible:

• The LAN to Wifi and Wifi to LAN scripts turn panels into network bridges
• The Warehouse deliveries and Monorail deliveries scripts work together to auto-scale the number of incoming cars to a Monorail Tower stop
• The Entity contents script reads the items in anything -- belt, machine, warehouse, monorail -- and converts them to signals

Factorio's influence

Networks have some aspects in common with Factorio networks:

• Signals with the same key automatically sum on the network. There's no concept of sender id or IP, just aggregated keys and values. If signals were packets they would be a kind of anonymous UDP broadcast
• Signals last one tick and must be resent every tick to be persistent

They differ in some other important ways though:

• A integer-zero signal is valid. The existence of the signal is independent of the value
• The keys are text strings, so while it's easy to use item names as keys, anything goes. If you want to prefix keys with sender id or a namespace for better control, that's fine

Future plans

• A wiki documenting the available API calls, possibly in-game
• More useful scripts will be bundled as they appear (occur to me!)
• The API will be expanded to allow deeper control of crafting machines
• AI Candles in networked clusters will be necessary for late-game