fitness tracker detect im asleep

[CrankyCoder]

i have been playing with a fitbit flex and ifttt. It almost works as i wanted. I was hoping since it always syncs with my phone that it would report the "sleep" event when i fall asleep. However, that is not the case. It reports the entire sleep cycle when i wake up. So my hope of "turn the lights off if i fall asleep on the couch" or something doesn't work right.

Anyone have any other thoughts on maybe something that detects sleep better?