I use Particle.IO products for a lot of my projects. They are controlled right now through IFTTT, but... that's sort of a hack and introduces a delay.
I'm trying to find out what arduino like devices are compatible with smartthings. Digital input / Digital output devices. Programmable Z/wave, Zigbee, or wifi devices. Anything like that.
This is partly to cut down on the cost of out of the box Z-Wave / Zigbee outlets and dimmers. Several LED strips can be controlled independently with an arduino or photon for ~$20. Temperature / motion sensors are also cheap and can be dropped on the same unit for just a few dollars more.