devices.py: Option to retry polling for thermostats with weak connection

Sometimes thermostats with weak connection can be sucessfully polled
after a short while. This commit adds the option 'retry_rerun' for
such an instance.

In case polling retries fail at the first attempt, another attempt is
started after finishing all other sensors. The option effectively
doubles the number of retry attempts.

The option defaults to 'False' for backward compatibility.

etrv2mqtt/devices.py

@@ -47,6 +47,7 @@ def poll(self, mqtt: Mqtt):
 
             if self._stay_connected == False:
                 self._device.disconnect()
+            return True
         except btle.BTLEInternalError as e:
             logger.error(e)
             if self._device.is_connected():
@@ -55,6 +56,7 @@ def poll(self, mqtt: Mqtt):
             logger.error(e)
             if self._device.is_connected():
                 self._device.disconnect()
+        return False
 
     def set_temperature(self, mqtt: Mqtt, temperature: float):
         try:
@@ -84,8 +86,16 @@ def __init__(self, config: Config, deviceClass: Type[DeviceBase]):
         self._mqtt.hass_birth_callback = self._hass_birth_callback
 
     def _poll_devices(self):
+        rerun = []
         for device in self._devices.values():
-            device.poll(self._mqtt)
+            if not device.poll(self._mqtt):
+                if self._config.retry_rerun:
+                    rerun.append(device)
+        if len(rerun)>0:
+            logger.warning("Attempting re-run of failed sensors in 5 seconds")
+            time.sleep(5)
+            for device in rerun:
+                device.poll(self._mqtt)
 
     def poll_forever(self) -> NoReturn:
         if self._config.poll_schedule == "hour_minute":

etrv2mqtt/schemas/config.schema.json

@@ -96,6 +96,11 @@
                     "minimum": 0,
                     "default": 5
                 },
+                "retry_rerun": {
+                    "type": "boolean",
+                    "description": "Retry failed thermostats once again after the end of the queue",
+                    "default": true
+                },
                 "stay_connected": {
                     "type": "boolean",
                     "description": "Set to true in order to leave BLE connection running after polling thermostat data or setting temperature. May drain battery.",