Support --ble on older firmwares that don't have the log-radio characteristic yet.

Author: ianmcorvidae

meshtastic/ble_interface.py

@@ -56,7 +56,8 @@ def __init__(
             self.close()
             raise e
 
-        self.client.start_notify(LOGRADIO_UUID, self.log_radio_handler)
+        if self.client.has_characteristic(LOGRADIO_UUID):
+            self.client.start_notify(LOGRADIO_UUID, self.log_radio_handler)
 
         logging.debug("Mesh configure starting")
         self._startConfig()
@@ -248,6 +249,12 @@ def read_gatt_char(self, *args, **kwargs):  # pylint: disable=C0116
     def write_gatt_char(self, *args, **kwargs):  # pylint: disable=C0116
         self.async_await(self.bleak_client.write_gatt_char(*args, **kwargs))
 
+    def has_characteristic(self, specifier):
+        if self.bleak_client.services.get_characteristic(specifier):
+            return True
+        else:
+            return False
+
     def start_notify(self, *args, **kwargs):  # pylint: disable=C0116
         self.async_await(self.bleak_client.start_notify(*args, **kwargs))