Has anyone successfully SET temperature via MQTT

[charles-pembroke]

Hi! Thanks for this amazing work reverse-engineering the Mysa MQTT protocol.

I'm trying to use your documented message format to SET thermostat temperatures,
but while my commands connect successfully and appear to be acknowledged, the
thermostats never actually change temperature.

I've tried:

• All 4 payload types (1, 3, 4, 5)
• With and without mode field
• With hold mode (ho: 2)
• Different thermostats

The Mysa app CAN control my thermostats, but API commands cannot.

Have you (or anyone) successfully SET a temperature remotely via the MQTT commands
documented in mysa_messages.md? Or does the documentation just show the message
format without confirming it actually works?

Any insights would be greatly appreciated!

[dlenski]

Have you (or anyone) successfully SET a temperature remotely via the MQTT commands
documented in mysa_messages.md? Or does the documentation just show the message
format without confirming it actually works?

Yes, it does work for me.

I've used these commands directly, but primarily I've been using liten_up for many months, to unlock the software-disabled features of my Mysa V2 Lite thermostats.

In order for this to work, it has to translate the setpoint messages between the v1 format and the v2 format. If I weren't sending the setpoint messages correctly, my V2 Lite thermostats wouldn't work; they don't respond to the V1 setpoint messages.

Any insights would be greatly appreciated!

Hmmm. Did you see this comment?

The Mysa apps actually send both of the following:

1. The setpoint message in the normal JSON format with QOS=1.

2. The setpoint message with the contents of the cmd field converted to a string. (e.g. "cmd": "[{\"sp\": 17, \"tm\": -1}]", instead of "cmd": [{"sp": 17, "tm": -1}]) 🤷🏻‍♂️

   If you run mysotherm and log MQTT messages, it will annotate these with (derpy stringified cmd) when it observes them.

I don't know why this situation exists, but I presume that there's a bug or mistake in the device firmware that causes some of them to only understand the stringified format, or to only understand the JSON format, and the developers decided to give up on fixing the firmware bugs and Just Send Both.