esp32(esp3D) WIFI module wont talk to marlin (serial port config?) (6 replies)

I'm working with a BTT SKR-2 motherboard and an esp32u add on board. It is the BTT variety of the add on, but the original firmware (if there was any?) is long gone.
I've manage to flash esp3d (3.0) to the wifi module. It created an access point that allowed me to get in and setup the webUI and its connection to my home network.
The whole esp3D web UI seems to be be functional, but it would seem there is no communication between my skr2 motherboard & esp3D.

so the wifi board runs & gets hooked to my network....probably something in marlin then, right?

My understanding is that the esp32 running the wifi acts the same as the serial usb port I use to sent commands to my printer, that is to say its a simple serial connection.
As such, I shouldn't need to mess with the actuall wifi config options, right? Should just be a matter of the right serial port assignments...heres what I have:

#define SERIAL_PORT -1  //emulated USB (hard line)
#define BAUDRATE 250000
#define SERIAL_PORT_2 6     //tested, did not work: 1,2,3, 
#define BAUDRATE_2 250000

in the comments of serial port 2, you can see the options I've tested. rather slow going having to compile each time.

does anyone know what the magic port setup is to make this work?
if not...

do the different serial port defs mean anything? could I reverse 0 & 2 without ill effect?

thanks for your help!

couple sidequests:,
anyone tell me what "marlin embedded" is as it pertains to wifi?
these esp boards have pins for an SPI connection, why aren't we using that? Wouldn't it be faster than serial?