temp_dallas_mqtt.py

temperature_publisher.py

import os
import glob
import time
import paho.mqtt.client as mqtt
import json

# --- MQTT Configuration ---
MQTT_BROKER = "homeassistant.local"  # Example: "192.168.1.100"
MQTT_PORT = 1883
MQTT_USERNAME = "mosquitto"
MQTT_PASSWORD = "Maskell1"

# --- State Topic ---
STATE_TOPIC = "ender3/enclosure/temperature/state" 

# --- Home Assistant Discovery Configuration ---
MQTT_DISCOVERY_PREFIX = "homeassistant" 
DEVICE_ID = "pi_temperature_sensor_01"   
UNIQUE_ID = "pi_temp_livingroom_01"      
SENSOR_NAME = "Living Room Temperature"

# --- DS18B20 Sensor Configuration ---
os.system('modprobe w1-gpio')
os.system('modprobe w1-therm')
base_dir = '/sys/bus/w1/devices/'
try:
    device_folder = glob.glob(base_dir + '28*')[0]
    device_file = device_folder + '/w1_slave'
except IndexError:
    print("Error: DS18B20 sensor not found. Check wiring and 1-Wire setup.")
    exit()

def read_temp_raw():
    with open(device_file, 'r') as f:
        lines = f.readlines()
    return lines

def read_temp():
    lines = read_temp_raw()
    while lines[0].strip()[-3:] != 'YES':
        time.sleep(0.2)
        lines = read_temp_raw()
    equals_pos = lines[1].find('t=')
    if equals_pos != -1:
        temp_string = lines[1][equals_pos+2:]
        temp_c = float(temp_string) / 1000.0
        return temp_c
    return None

def publish_discovery_message(client):
    """Publishes the discovery message for Home Assistant."""
    discovery_topic = f"{MQTT_DISCOVERY_PREFIX}/sensor/{DEVICE_ID}/{UNIQUE_ID}/config"
    discovery_payload = {
        "name": SENSOR_NAME,
        "state_topic": STATE_TOPIC,
        "unit_of_measurement": "°C",
        "value_template": "{{ value }}", 
        "unique_id": UNIQUE_ID,
        "device_class": "temperature",
        "device": {
            "identifiers": [DEVICE_ID],
            "name": "Raspberry Pi Temperature Monitor",
            "model": "Pi with DS18B20",
            "manufacturer": "Raspberry Pi Foundation"
        }
    }
    print(f"Publishing Home Assistant discovery message to: {discovery_topic}")
    client.publish(discovery_topic, json.dumps(discovery_payload), retain=True)

def on_connect(client, userdata, flags, rc):
    if rc == 0:
        print("Connected to MQTT Broker!")
        # Announce the sensor to Home Assistant upon connecting
        publish_discovery_message(client)
    else:
        print(f"Failed to connect, return code {rc}\n")

def setup_mqtt_client():
    client = mqtt.Client()
    client.username_pw_set(MQTT_USERNAME, MQTT_PASSWORD)
    client.on_connect = on_connect
    client.connect(MQTT_BROKER, MQTT_PORT, 60)
    return client

def main():
    mqtt_client = setup_mqtt_client()
    mqtt_client.loop_start()

    print("Starting temperature publisher service.")
    try:
        while True:
            temp_c = read_temp()
            if temp_c is not None:
                print(f"Temperature: {temp_c:.2f}°C. Publishing to {STATE_TOPIC}")
                mqtt_client.publish(STATE_TOPIC, f"{temp_c:.2f}", retain=True)
            else:
                print("Failed to read temperature.")
            
            time.sleep(60)
    except KeyboardInterrupt:
        print("Publication stopped.")
    finally:
        mqtt_client.loop_stop()
        mqtt_client.disconnect()

if __name__ == '__main__':
    main()