reverse engineering control recuperation fan

I’ve Vento Eco A50 S1 Pro with control panel.

I’ve wondering how can i manage motor without control panel. Control panel is connected with motor thru connector ±TP.

I made some measurement:

Device connected to 12V without control panel
Fan is not working and line T has 5V and line P 4V

If I connect control panel and set one of three speeds I get:
Line T 2,6V no changes not depend from direction rotation and speed level
Speed level:
I Line P 1,8V or 2,6V (depend from direction of rotation)
II Line P 1,2V or 3,1V (depend from direction of rotation)
III Line P 0,5V or 3,6V (depend from direction of rotation)

My goal is to connect device to esp/arduino and menage thru some mqtt without wall control panel.
Why on T and P is some V when ± is connected to 12V?
In most arduino projects control lines are set to out and thru output some V from board we controling speed rotation devices etc.
How can I manage T and P lines and control my vent in this situation?
link to example/analogous project will’be nice :slight_smile: