def read_publish_sensor_data():
""" Function used to read sensor data and publish the readings to a topic
served by an MQTT server.
"""
# MQTT client publisher
mqtt_publisher = MQTTPublisher()
sensor_serial = ini_config.get("Sensor", "SENSOR_TEMPERATURE_SERIAL")
sleep_timeout = ini_config.getint("Sensor", "SENSOR_SLEEP_TIME")
# start daemon forever loop
while True:
try:
# read and publish sensor reading to topic in MQTT server
logging.debug("publishing sensor serial [{0}] data".format(sensor_serial))
mqtt_publisher.publish_temperature(sensor_serial)
except (Exception) as err:
sys.stderr.write(str(err))
logging.exception("Error reading/publishing sensor data. [{0}]".format(err))
except: # catch *all* other exceptions
err = sys.exc_info()[0]
logging.exception("Error occurred in mqtt daemon: [{0}]".format(err))
write_to_file("<p>Error in mqttpublisher daemon: [{0}]</p>".format(err), sys.stderr)
time.sleep(sleep_timeout)
return