raspberrypi/userland — pull request #103 by JamesH65 (2013-10-15 11:25:47+00:00)
Title: Added a signal mode to allow initiation of captures from another process...

....

Waits on SIGUSR1 between captures.

Fixed a possible issue with black frames in timelapse mode where
-tl 0 is used. Ensures the first frame has plenty of time to get its exposure
right.