serial2mqtt.py

# シリアルポートで受信したデータを MQTT Broker に投げる 
from paho.mqtt import client as mqtt_client
import random
import time
import asyncio
from serial_asyncio import open_serial_connection
import sys

args = sys.argv
name = args[1]       # COM3 などを引数で指定する (例: python serial2mqtt.py COM3 )
broker = 'localhost' # MQTT Brokerのホスト
port = 1883
client_id = f'python-mqtt-{name}-{random.randint(0, 1000)}'
print(f"{name} = {client_id}")

def connect_mqtt():
    def on_connect(client, userdata, flags, rc):
        if rc == 0:
            print("Connected to MQTT Broker!")
        else:
            print("Failed to connect, return code %d\n", rc)
    # Set Connecting Client ID
    client = mqtt_client.Client(client_id)
#    client.username_pw_set(username, password)
    client.on_connect = on_connect
    client.connect(broker, port)
    return client

async def main():
    client = connect_mqtt()
    client.loop_start()
    reader, writer = await open_serial_connection(url=name, baudrate=115200)
    while True:
        line = await reader.readline()
        # topic と message に分ける
        data = str(line).split(' ')
        if len(data) == 2 and data[1][0] == '{':
            # 文字列を無理やり加工している部分をなおす
            topic = str(data[0])[2:]
            msg = str(data[1]).replace("\\r\\n","")[0:-1]
            result = client.publish(topic, msg)
            status = result[0]
            if status == 0:
                print(f"{topic}\t{msg}")
            else:
                print(f"Error: {line}")
        else:
            print(f"Skipped: {line}")

asyncio.run(main())