Fix automatic delay detection

src/python_spectrometer/daq/simulator.py

@@ -59,12 +59,12 @@ def with_delay(meth):
 
     @wraps(meth)
     def wrapped(self, *, delay=True, **settings):
-        skip_wait = getattr(wrapped, '__with_delay', False)
+        skip_delay = settings.pop('_skip_delay', False)
 
         if delay is True:
             delay = settings['n_pts'] / settings['fs']
 
-        it = meth(self, **settings)
+        it = meth(self, _skip_delay=True, **settings)
         while True:
             tic = time.perf_counter()
             try:
@@ -72,8 +72,8 @@ def with_delay(meth):
             except StopIteration as stop:
                 return stop.value
             else:
-                if delay and not skip_wait:
-                    time.sleep(delay - (time.perf_counter() - tic))
+                if delay and not skip_delay:
+                    time.sleep(max(0, delay - (time.perf_counter() - tic)))
 
                 yield data
 
@@ -91,7 +91,6 @@ def with_delay(meth):
         parameters = parameters + [delay_param]
 
     wrapped.__signature__ = wrapped_sig.replace(parameters=parameters)
-    wrapped.__with_delay = True
     return wrapped