Art-Net DMX

[admin]

Resident script, sleep time = 0. Might require some change to work with C-BUS objects.

Code:

if not client then
  ip = '192.168.2.43'
  mapping = { '1/1/1', '1/1/2', '1/1/3', '2/1/1', '2/1/2', '2/1/3' }
  universe = 1
  physical = 0

  udpsock = require('socket').udp()

  addrtoid = {}
  values = {}

  for id, addr in ipairs(mapping) do
    obj = grp.find(addr)
    addrtoid[ addr ] = id

    if obj then
      value = obj.value or 0

      if obj.datatype == dt.scale then
        value = math.floor(value * 2.55)
      end
    else
      value = 0
    end

    values[ id ] = value
  end

  function send()
    local cmd = string.char(
      -- null byte; ARTNET_DMX opcope; protocol version 14, sequence not defined
      0, 0, 0x50, 0, 14, 0,
      -- physical input port from which DMX512 data was input
      bit.band(physical, 0xFF),
      -- 15 bit Port-Address (universe)
      bit.band(universe, 0xFF), bit.rshift(universe, 8),
      -- Length
      bit.rshift(#values, 8), bit.band(#values, 0xFF)
    )

    local req = 'Art-Net' .. cmd .. string.char(unpack(values))
    udpsock:sendto(req, ip, 0x1936)
  end

  function eventhandler(event)
    local id = addrtoid[ event.dst ]
    if id then
      values[ id ] = busdatatype.decode(event.datahex, dt.uint8, event.dstraw)
      send()
    end
  end

  client = require('localbus').new()
  client:sethandler('groupwrite', eventhandler)

  send()
end

client:step()