ATXD35A5V with S403 System is offline. Any solutions?

[RaW79]

Hi
Just installed a Faikin at a Siesta Essence (ATXD35A5V1B) connect at known S403 (4 wires excluding 5V). But now the Faikin (current Layout from August 2024) only says "System offline". Yes it's not listed in the supported Models list, but any solutions known?
My Board:

The LED ist Mangenta. Do I have to Set the model Code manually or do i have to do a Special Setup (inverted TX or RX)?

S403 is connected this way (do not check cabling based on colour, there is a crossing/soldering point in the middle):

Big thanks!

[revk]

It will try inverting tx/rx automatically and try S21 and X50A. So no, it should just work.

Double check what others have posted re the S403.

[revk]

When connected to aircon the aircon should have internal 5V pull ups. It does in an S21.

If not then you need to find and connect 5V pin to failin to force the pull ups.

[RaW79]

Do you know If this is Just for Initial detection at Startup? In an Analysis Here for the S403 someone used 20k Resistor from the 14VDC to the 5VDC Pin of the Faikin. Good Idea for Testing?
If this works would think of usiing a LDO for this instead of doing DIY things on the Daikin PCB. What do you think?

[revk]

The 5V pull up is needed fort tx to work as the processor is 3.3V. An S21 normally has one in the air-con.

[RaW79]

Thanks for your support and help. It´s fully working without 5V connection or any additional Pullup or so.
First part of the problem was a RX/TX switch in my cable which I recognized very early but solving this issue by a changed configuration in the Faikin setup did not work for me.
So now I changed the wires according standard GPIO usage and this works!
Maybe there is a problem in the faikin software by using GPIO 34 as TX and GPIO 48 as RX, don´t know and better avoid!

[revk]

You can't swap the ports. They have hardware that is directional. Did not know you had done that. Glad you sorted.

[RaW79]

Thanks and may the config options may offer too much freedom which isn´t really there. Maybe a hint text would be great to improve:

Nevertheless again staying close to standard isn´t a bad option :)

[revk]

The software can run on other boards where the config needs to be configurable. Sorry.

[RaW79]

No need for a "sorry". Just mentioning my impression with the intention to help to improve your great solution. A hint in the docs or hint in the menu ("In case of standard faikin module, do not change") would maybe help also others...