fix it properly

common/realtime.py

@@ -48,11 +48,15 @@ class Ratekeeper:
   def __init__(self, rate: float, print_delay_threshold: float | None = 0.0) -> None:
     """Rate in Hz for ratekeeping. print_delay_threshold must be nonnegative."""
     self._interval = 1. / rate
-    self._next_frame_time = time.monotonic() + self._interval
     self._print_delay_threshold = print_delay_threshold
+    self._process_name = getproctitle()
+    self.reset()
+    self._last_monitor_time = -1
+
+  def reset(self):
     self._frame = 0
     self._remaining = 0.0
-    self._process_name = getproctitle()
+    self._next_frame_time = time.monotonic() + self._interval
     self._dts = deque([self._interval], maxlen=100)
     self._last_monitor_time = time.monotonic()
 
@@ -79,6 +83,9 @@ def keep_time(self) -> bool:
 
   # Monitors the cumulative lag, but does not enforce a rate
   def monitor_time(self) -> bool:
+    if self._last_monitor_time < 0:
+      self.reset()
+
     prev = self._last_monitor_time
     self._last_monitor_time = time.monotonic()
     self._dts.append(self._last_monitor_time - prev)

system/micd.py

@@ -43,6 +43,7 @@ def apply_a_weighting(measurements: np.ndarray) -> np.ndarray:
 
 class Mic:
   def __init__(self):
+    self.rk = Ratekeeper(RATE)
     self.pm = messaging.PubMaster(['microphone'])
 
     self.measurements = np.empty(0)
@@ -59,6 +60,7 @@ def update(self):
     msg.microphone.soundPressureWeightedDb = float(self.sound_pressure_level_weighted)
 
     self.pm.send('microphone', msg)
+    self.rk.keep_time()
 
   def callback(self, indata, frames, time, status):
     """
@@ -92,11 +94,8 @@ def micd_thread(self):
 
     with self.get_stream(sd) as stream:
       cloudlog.info(f"micd stream started: {stream.samplerate=} {stream.channels=} {stream.dtype=} {stream.device=}, {stream.blocksize=}")
-
-      self.rk = Ratekeeper(RATE)
       while True:
         self.update()
-        self.rk.keep_time()
 
 
 def main():