Run show at same time on E682 for pixels and Raspberry pie and sansmart for a/c

[teamflash44]

So I'm brand new and this is my first show set up.  Obviously I'm a little late to the dance this year but I'm rushing to catch up ...lol.  I am building an E682 controller to run a 5V pixel mega tree, arches, and a couple of spiral trees.  I am also trying to put together an inexpensive controller and SSR to run some a/c lights such as some kaleidoscope floods and store bought LED strings.  I have a ton of A/C lights and want to be able to still use them but I have spent most of my budget on the E682 kit and all the new pixel stuff.  So I came across this "cheapskate" video https://www.youtube.com/watch?v=WvG9c84ApFA showing an inexpensive sansmart relay board being run off a mega 2560 Arduino.  I also came across some videos showing basically the same thing running of a Raspberry PI. So I have it mostly figured out except .... can I run these two systems together of a single Xlights sequence? Do I install FPP software on PI even though I do not have a Falcon controller?  Do I connect the PI and the E682 to a network switch that is connected to the show computer or can I run the whole show on the PI?  Can I output to the E682 at the same time as the sansmart relay?  I think the E682 is a cat5 connection and the sansmart is USB?  Does Xlights have controller info to run the sansmart relay board through the PI?  I guess I'm not sure of the software piece to make it all work together.  The hardware part I think I have figured out .... mostly.
Thank you in advance for the assistance!!

[keithsw1111]

If you hang the relay board off the Pi then it either runs it directly in master mode or it runs on bridge mode and XLights sends it e131 data. XLights can also drive serial directly but only if they understand Dmx or opendmx.

[teamflash44]

Thank you for the reply Keith.  So I am just having a hard time wrapping my head around the software side of this.  Do you (or anyone reading) know if the Sainsmart relay boards are operated by DMX?  I would really like to run the whole show from the PI but it would need to be able to communicate with the relay board and the E682 at the same time.  I have seen videos where the PI will run the relay board so I'm sure if I use the laptop to run the show and use the PI just as a controller for the board, that would work but I'm not sure if the PI can run both boards as the show computer?  Do I need to install FPP on the PI in either situation?
Thanks again for the help

[keithsw1111]

I know nothing about the sainsmart. I would be asking what protocol it uses.

[teamflash44]

So reading some post on other boards, it looks like the Sainsmart boards will take E1.31 protocol.  I should be able to output through the USB of the PI to the relay I think?  Or they also make boards that I can connect direct to the PINS of the PI.  If I do that, can I still output through the network port to the E682 at the same time or at that point would I just be using the PI as the controller and I would run the show from a laptop with a network switch connecting both boards to the laptop?
Thanks for the help, just not sure how the software and the network all works together to control two different types of boards.