Raspberry Pico W MQTT client -- Local Mosquitto Broker Connection problem

[GurraE]

For quite some time I have used ESP32 boards running MicroPython and the MQTT client from :
https://github.com/leiyong711/micropython-mqtt-1/blob/master/src/mqtt.py
connecting to a local Mosquitto MQTT broker (running on a Raspberry Pi 4).

This has been working perfectly for the ESP32, but when trying the same (simple) program on a Raspberry Pico W it won't connect/stay connected to the local Mosquitto broker.
.
The client message i get is :
Connecting to MQTT broker....
Exception caught opening MQTT socket: OSError(113,)
Connecting to MQTT broker....
Exception caught opening MQTT socket: OSError(113,)
etc.

The Client software code is simply a copy of the github/leiyong711/... mqtt example code...

---

_import micropython
from libs.mqtt import MQTTClient

def puback_cb(msg_id):
print('PUBACK ID = %r' % msg_id)

def suback_cb(msg_id, qos):
print('SUBACK ID = %r, Accepted QOS = %r' % (msg_id, qos))

def con_cb(connected):
if connected:
client.subscribe('subscribe/topic')

def msg_cb(topic, pay):
print('Received %s: %s' % (topic.decode("utf-8"), pay.decode("utf-8")))

client = MQTTClient('192.168.1.1', port=1883)

client.set_connected_callback(con_cb)
client.set_puback_callback(puback_cb)
client.set_suback_callback(suback_cb)
client.set_message_callback(msg_cb)

client.connect('my_client_id')

while True:
if client.isconnected():
try:
pub_id = client.publish('publish/topic', 'payload', False)
except Exception as e:
print(e)

utime.sleep_ms(1000)_

---------------------------------------

I am using the same settings on the Pico W as on the ESP32, I am on the same subnet, I have tried with/without anonymous logins, checked qos, timeout etc. etc. but the Pico W just won't connect/stay connected.

I have updated the Pico W with the latest firmware (20221220), and the Mosquitto Broker version is 2.0.11

The output from the mosquitto log file is :
671721470: New client connected from 192.168.0.128:56930 as 29 (p2, c1, k60, u'gurra').
immediately followed by :
1671721470: Client 29 closed its connection.

I have also tried connecting the Pico W to my local Home Assistant MQTT Broker with the same result (the ESP32 logs in just fine, but not the Pico W)...

How do I get on here ???

[peterhinch]

I don't know the answer but this module has been tested with the Pico W. Alternatively you could raise an issue against the library you are using.

[GurraE]

@peterhinch

I did a complete "makeover" and replaced the mqtt-module with your mqtt_as.py module & now everything works just fine (both for ESP32 & RPi PICO W), so THANK YOU !!!!

Regarding the mqtt_as.py routine :

Question #1 :
Before using the mqtt_as.py module, I had to get the IP & MAC-info using a separate function :

Now as the WiFi part is "built-in" into your module, how can I access this info (IP/mask/GW/DNS & MAC) ??

---

Question #2 :

I have my PUB & SUB topics specified as strings like :
pub_topic = 'outgoing'
sub_topic = 'incoming'

As the mqtt_as-module expects them as byte strings i am converting them using :
await client.publish(bytes(pub_topic, 'utf-8'), msg, qos=1)

This works fine for publish, but for subscribe I have to use the string name :
await client.subscribe('incoming', 1)

Is there a difference (or just me having more bad luck :-) ....

[peterhinch]

You don't need these details to run mqtt_as but I guess you have your own reason for wanting them. It's OK to connect to the network before you start mqtt_as, so you can get your config details then. Given that mqtt_as restores the link as soon as possible after an outage, DHCP will allocate the same IP address. I can't think of a circumstance where the details may change.

Re strings/bytes see the docs and the test scripts.

If you do need to convert between strings and bytes use string.encode() and bytes.decode().