fix: update event handling in MiniMateClient and protocol to ensure correct sequence for waveform downloads

minimateplus/protocol.py

@@ -241,6 +241,29 @@ class MiniMateProtocol:
         log.debug("read SUB=0x%02X: received %d data bytes", sub, len(data_rsp.data))
         return data_rsp.data
 
+    def poll(self) -> S3Frame:
+        """
+        Send a single POLL (SUB 5B) probe+data cycle and return the data response.
+
+        This is a bare POLL cycle with no boot-string drain — use during an active
+        session (contrast with startup(), which drains the "Operating System" boot
+        string first).
+
+        Confirmed from 4-2-26 BW TX capture: BW sends exactly 3 of these POLL
+        cycles between the last 1F and the first 5A probe frame during every
+        waveform download.  Without them the device ignores the 5A probe.
+        """
+        self._send(POLL_PROBE)
+        self._recv_one(
+            expected_sub=_expected_rsp_sub(SUB_POLL),
+            timeout=self._recv_timeout,
+        )
+        self._send(POLL_DATA)
+        return self._recv_one(
+            expected_sub=_expected_rsp_sub(SUB_POLL),
+            timeout=self._recv_timeout,
+        )
+
     def send_keepalive(self) -> None:
         """
         Send a single POLL_PROBE keepalive without waiting for a response.