code: def interval_wait(self):
          
          # calculate time since last interation and wait to acheive desired interval
          now = time.time()
          elapsed = (now - self.last_tick)*1000
          # print("interval %d, time from start %d \n" % (elapsed, (now - self.start_time)*1000))
          if elapsed < self.interval:
              # print('sleep ', (self.interval-elapsed))
              # self.signals.warning.emit('') # clear previous warning
              time.sleep((self.interval-elapsed)/1000)
              now = time.time()
          elif elapsed > self.interval:
              pass
              # self.signals.warning.emit("WARNING: PROVIDED INTERVAL EXCEEDED, ELAPSED TIME %d" % (elapsed))
          self.last_tick = now
docs: Pauses the correct amount of time according to this 
          acquisition object's interval setting, and the last time this 
          function was called