Push POE project

sensor_bridge.py

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+import logging
+import json
+import time
+from datetime import datetime
+from pymodbus.client import ModbusTcpClient
+from pymodbus.exceptions import ModbusException
+
+# Add MQTT client
+import paho.mqtt.client as mqtt
+
+# Import configuration
+from config import (
+    MODBUS_HOST, MODBUS_PORT, UNIT_ID,
+    MQTT_BROKER, MQTT_PORT, MQTT_TOPIC, MQTT_CLIENT_ID, 
+    MQTT_USERNAME, MQTT_PASSWORD, LOCATION, PUBLISH_INTERVAL
+)
+
+# Setting logging basic to see output
+logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
+
+# MQTT callbacks
+def on_connect(client, userdata, flags, rc):
+    if rc == 0:
+        logging.info("Connected to MQTT Broker!")
+    else:
+        logging.error(f"Cannot connect to MQTT Broker. Return code: {rc}")
+
+def on_publish(client, userdata, mid):
+    logging.info(f"Successfully sent message with ID: {mid}")
+
+def read_and_publish_data(mqtt_client, modbus_client):
+    """Read data from Modbus and publish to MQTT"""
+    try:
+        # Check connection to Modbus server
+        if not modbus_client.is_socket_open():
+            if not modbus_client.connect():
+                logging.error("Cannot connect to Modbus server.")
+                return False
+
+        # Read temperature (register 0)
+        result_temp = modbus_client.read_holding_registers(address=0, count=1, slave=UNIT_ID)
+
+        # Read humidity (register 1)
+        result_hum = modbus_client.read_holding_registers(address=1, count=1, slave=UNIT_ID)
+
+        # Initialize data to publish
+        data = {
+            "time": datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S"),
+            "location": LOCATION
+        }
+
+        # Process temperature
+        if hasattr(result_temp, 'registers') and result_temp.registers:
+            raw_temp = result_temp.registers[0]
+            raw_temperature = raw_temp * 0.1
+            temperature = raw_temperature - 40
+            logging.info(f"Raw temperature: {raw_temperature:.1f}°C (raw: {raw_temp})")
+            logging.info(f"Corrected temperature: {temperature:.1f}°C")
+            data["temperature"] = round(temperature, 1)
+        else:
+            logging.error(f"Error reading temperature: {result_temp}")
+            return False
+
+        # Xử lý độ ẩm
+        if hasattr(result_hum, 'registers') and result_hum.registers:
+            raw_hum = result_hum.registers[0]
+            humidity = raw_hum * 0.1
+            logging.info(f"Humidity: {humidity:.1f}%RH (raw: {raw_hum})")
+            data["humidity"] = round(humidity, 1)
+        else:
+            logging.error(f"Error reading humidity: {result_hum}")
+            return False
+
+        # Convert data to JSON with a better format
+        # indent=2 creates whitespace and newlines for JSON
+        payload = json.dumps(data, indent=2)
+        logging.info(f"Publishing data: {payload}")
+        result = mqtt_client.publish(MQTT_TOPIC, payload)
+        
+        # Ensure data is sent
+        result.wait_for_publish()
+        
+        if result.is_published():
+            logging.info(f"Successfully published data to topic '{MQTT_TOPIC}'")
+            return True
+        else:
+            logging.error("Cannot publish data")
+            return False
+
+    except Exception as e:
+        logging.error(f"Error in reading/writing data: {e}", exc_info=True)
+        return False
+
+def main_loop():
+    """Main function to connect and publish data in cycles"""
+    # Initialize MQTT client
+    mqtt_client = mqtt.Client(client_id=MQTT_CLIENT_ID)
+    mqtt_client.on_connect = on_connect
+    mqtt_client.on_publish = on_publish
+    
+    # Set username and password if needed
+    if MQTT_USERNAME and MQTT_PASSWORD:
+        mqtt_client.username_pw_set(MQTT_USERNAME, MQTT_PASSWORD)
+    
+    # Initialize Modbus TCP client
+    modbus_client = ModbusTcpClient(
+        host=MODBUS_HOST,
+        port=MODBUS_PORT,
+        timeout=30
+    )
+    
+    try:
+        # Connect to MQTT broker
+        mqtt_client.connect(MQTT_BROKER, MQTT_PORT, 60)
+        mqtt_client.loop_start()
+        logging.info(f"Attempting to connect to Modbus TCP server: {MODBUS_HOST}:{MODBUS_PORT}...")
+        
+        # Connect to Modbus server
+        if not modbus_client.connect():
+            logging.error("Cannot connect to Modbus server initially.")
+            return
+
+        logging.info("Successfully connected to Modbus server.")
+        logging.info(f"Starting data reading cycle every {PUBLISH_INTERVAL} seconds...")
+        
+        try:
+            # Main loop to read and publish data
+            while True:
+                success = read_and_publish_data(mqtt_client, modbus_client)
+                
+                if not success:
+                    logging.warning("Error occurred in current cycle, will retry in next cycle.")
+                
+                # Wait for next publish cycle
+                logging.info(f"Waiting {PUBLISH_INTERVAL} seconds until next publish...")
+                time.sleep(PUBLISH_INTERVAL)
+                
+        except KeyboardInterrupt:
+            logging.info("Received stop signal from user.")
+    
+    except Exception as e:
+        logging.error(f"Unexpected error in main loop: {e}", exc_info=True)
+    
+    finally:
+        # Close Modbus connection
+        modbus_client.close()
+        logging.info("Successfully closed Modbus connection.")
+        
+        mqtt_client.loop_stop()
+        mqtt_client.disconnect()
+        logging.info("Successfully closed MQTT connection.")