ESP32 + pms5003 + MQTT

[TomasTnr]

Hi Guys,
I am new in Micropython and I need learn a lot yet but i now am busy with project at home to use ESP32 and PMS5003 to send via mqtt data to Home Assistant.
I could use Arduino code but i want to learn micropython.

Til now i used librabry pms5003.py and main.py as follows:

import pms5003
import machine
import uasyncio as asyncio

uart = machine.UART(1, tx=25, rx=26, baudrate=9600)
pm = pms5003.PMS5003(uart)
pm.registerCallback(pm.print)

loop=asyncio.get_event_loop()
loop.run_forever()

Everyth works as it should but then i wrote a code to send this data via MQTT

import machine
import pms5003
import uasyncio as asyncio
from umqtt.simple import MQTTClient

# Initialize MQTT parameters
mqtt_broker = "xxx.xxx.xxx.xxx"  # Your MQTT broker IP address
mqtt_port = 1883  # Your MQTT broker port
mqtt_topic = "pms5003"  # Topic to publish the sensor readings
mqtt_client_id = "pms5003_client"  # Client ID for MQTT connection
mqtt_username = "XXXXXXXXXXXX"  # MQTT username
mqtt_password = "XXXXXXXXXXXX"  # MQTT password

# Initialize UART for PMS5003 sensor
uart = machine.UART(1, tx=25, rx=26, baudrate=9600)
pm = pms5003.PMS5003(uart)

# Initialize MQTT client
mqtt_client = MQTTClient(mqtt_client_id, mqtt_broker, mqtt_port, mqtt_username, mqtt_password)

async def read_sensor_and_publish():
    while True:
        data = await pm.read()
        if data is not None:
            # Publish sensor readings to MQTT topic
            mqtt_payload = "PM1.0: {}, PM2.5: {}, PM10: {}".format(data[0], data[1], data[2])
            mqtt_client.publish(mqtt_topic, mqtt_payload)
        await uasyncio.sleep(60)  # Publish readings every 60 seconds

async def main():
    # Connect to MQTT broker
    mqtt_client.connect()
    # Start reading sensor and publishing readings to MQTT
    uasyncio.create_task(read_sensor_and_publish())

pm.registerCallback(pm.print)

# Run the main coroutine
# loop=asyncio.get_event_loop()
# loop.run_forever()
uasyncio.run(main())

I know someth is wrong but i don't know what and i think that my little knowledge is the issue ;)
Can someone help me with this?

PS. I have code to connect to WIFI in boot.py

[peterhinch]

Your use of asyncio is incorrect. Firstly with recent firmware you can forget about uasyncio. Just import asyncio and use it.

The problem is that main will run to completion (.create_task returns immediately). Once main has terminated, asyncio.run will terminate and the application will quit, returning to the REPL before it has a chance to do anything useful. I would do something like this:

async def main():
    mqtt_client.connect()
    while True:
        data = await pm.read()
        if data is not None:
            # Publish sensor readings to MQTT topic
            mqtt_payload = "PM1.0: {}, PM2.5: {}, PM10: {}".format(data[0], data[1], data[2])
            mqtt_client.publish(mqtt_topic, mqtt_payload)
        await uasyncio.sleep(60)  # Publish readings every 60 seconds

pm.registerCallback(pm.print)
asyncio.run(main())

This assumes that pm.read() is an asynchronous function - I'm unfamiliar with the library.

Resources which may be of interest: asyncio tutorial. Once you've got MQTT working you might want to look at asynchronous MQTT.