Ok, i solved my issue with the serial not working.
I think the male-male db9 connector is wired 1:1 and thus not giing correct pinning on my modified rj45 to rs232 cable.
Removed that one and made a new cable and it started working.

Looking at the examples above at least has helped me to understand ...

I have been trying to figure this out for some time now.
Trying to move from a rpi with usb2serial dongle to esp32/esp8266 based setup but it just wil not work.

I am using a Tzt MAX3232 RS232 Serial Port Ttl Converter Module DB9 Connector MAX232 For Arduino
rs232.jpg and and ESP32 and have tried ...

Hi All,

i have the script working and i am able to control my Zehnder 950 basic.
I however am trying to find a way to control the inflow fan (Zuluft Ventilator) so i can automatically turn off this fan to prevent hot air in my house duriong summers.

In the protocol document (http://www.see ...