I have an external C file that I'm using, and would like to call usleep() (or nanosleep()). Unfortunately, the appropriate headers aren't included in the standard include path, and just dropping them in there doesn't work, either. Are there any other alternatives to causing a >1ms delay within an external C file included in my sketch?
Are you looking for something like delay...
Unfortunately, no. I need both a delay shorter than 1ms, and I need to be able to call it from an external C file.
http://arduino.cc/en/Reference/DelayMicroseconds
theres also delay microseconds
(course your op said greater than 1ms, but i wont tell :-X)
wondering why the external c file tho
It's an external C file because it's just got to be there... Using an external library for which I'm writing in C. DelayMicroseconds really doesn't help. I appreciate the effort, though!
Use a delay provided by avr gcc ?
http://www.nongnu.org/avr-libc/user-manual/group__util__delay.html
It's an external C file because it's just got to be there
ok just wonderin 
Use a delay provided by avr gcc ?
avr-libc: <util/delay.h>: Convenience functions for busy-wait delay loops
Perfect--thanks!