Error: received null username or password for unpwd check

[xxMario1995xx]

Hi,

I’m trying to use GroBro with a Growatt inverter using local MQTT (no cloud).

My problem seems to be a fundamental mismatch between Growatt’s MQTT client and Mosquitto authentication requirements.

New connection from 172.30.32.1:56766 on port 8883. error: received null username or password for unpwd check

Important details
• The Growatt mobile app does NOT allow setting a username or password for MQTT
• Username/password fields are always empty
• TLS can be enabled, but auth credentials cannot be configured
• Mosquitto rejects the connection because:

This suggests that the Growatt inverter always connects without credentials.

1.	Is Growatt local MQTT expected to work without authentication only?
2.	Is there a recommended way to run GroBro without Mosquitto authentication?
3.	Is using a separate Mosquitto instance without auth (e.g. Raspberry Pi) the intended solution?

Thank you for help!!

[robertzaage]

Hi,

I converted your issue into a discussion as I suspect your problem is a configuration issue.

1. Growatt devices expect an authentication workflow and won’t connect anonymously
2. No, this is not possible. See No. 1 😄
3. Indeed you can use GroBro as a bridge between the broker your Growatt device is connected to and the broker your Home Assistant is configured to, but I‘m unsure if this would solve your problem. (See SOURCE_ and TARGET_ environment variables)

Did you try to setup an account for your inverter with the device serial as username and „Growatt“ as password?