I'd have to search the Forum and the GitHub archives; but, yes, it ought to be simpler.
My #1 suggestion: Lookup the recent ESP2866 (? -- doh... I can't even remember the chip number!) as what probably is an excellent example.
I'm presuming you are using LAN or WiFi with the Arduino, not the ThingShield (ZigBee based)?
The Docs are worth reading so you can understand the official architecture and pieces, but you don't need all the complexity described http://docs.smartthings.com/en/latest/cloud-and-lan-connected-device-types-developers-guide/building-lan-connected-device-types/building-the-service-manager.html.
I'll update this post if I find the ESP example I refer to above...
But at first glance the above appears to be a one-direction to the LAN device.
Not sure how to get responses from back from the LAN device, but that may be buried in code for Hue and Hue (Connect).
Or, expose your device to the web, and then you can use a "graph.api" path with
Let me know where take the convo from here. Go PM if you want... though I'd appreciate a bit of tutorial / consulting fee for custom one:one work.