I have a PC upstairs running my 3D printing slicer program (Simplify 3D). In the basement, I have several USB-enable 3D printers. My PC upstairs has a USB-to-RS-232 serial adapter. The serial side of that USB-to-Serial adapter connects to the Serial port of a Moxa Nport 6150 RS232-to-Ethernet protocol adapter. I get those Moxa devices for free when they break at work and then fix them for a couple of dollars.
The other side of the Moxa connects to my home computer network router. In the basement I can plug another Moxa into an ethernet cable on my home network and the serial RS232 output I need to connect to the Micro-USB jack of the 3D printer. How can I use an Arduino Nano (or Uno or Mega if required) to convert the RS232 data to the USB input of my 3D printer?
So I have PC->(RS-232)->[MOXA(RS-232)->Moxa(Ethernet)]->Router->[Moxa(Ethernet)->Moxa(RS-232)]->[Arduino(RS-232)->Arduino(USB)]->3D Printer(USB)... How can I get the Arduino to do that function? Items within [ and ] brackets are single devices performing a protocol conversion.
I know people use Raspberry Pi's and a program called OctoPrint to remotely control their 3D printers but I get the Moxas for free and Uno's or Nanos are dirt cheap. RPi's are more expensive and for several 3D printers it can start adding up. Any ideas?