Art-Net DMX

[admin]

Here's a simplified function. Change universe number as needed, sequence and physical parameters can probably be zero. Value is the output channel value ranging from 0 to 255.

Code:

function artnet_dmx(ip, sequence, physical, universe, data)
 local cmd = string.char(
   -- null byte
   0,
   -- ARTNET_DMX opcope
   0, 0x50,
   -- protocol version 14
   0, 14,
   -- sequence number is used to ensure that ArtDmx packets are used in the correct order
   bit.band(sequence, 0xFF),
   -- 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(#data, 8), bit.band(#data, 0xFF)
 )

 local req = "Art-Net" .. cmd .. string.char(unpack(data))

 local sck = require("socket").udp()

 sck:sendto(req, ip, 0x1936)
 sck:close()
end

ip = '192.168.2.43'
universe = 123
value = 255
artnet_dmx(ip, 0, 0, universe, { value })