[Q] how notification lights work?

[zen kun]

how this are working? i just got my atrix yesterday but not sure what kind of ecents trggers notifications lights, since seems sms pop up not working there is an Trackball alert or something like this?
Thanks

 

[dLo GSR]

if you want full control over the led (events, colors, etc) get the app "lightflow"

 

[fmora176]

I have the Lightflow app installed (lite version) however it seems that changing the notification speed has no effect..it doesn't blink often enough for my taste, is there any way to fix this? other than that the app works great..