Refresh causes hiccups

I am running a real-time controller. I want to occasionally update the
window (once per second) to display certain variables that I want to
monitor. I have tried using printf()and addstr()/refresh() (curses), but it
causes a major “hiccup” in my application. Is there any way to update a
small area on the screen so that it does not disrupt my real-time control
application?