Hi Robin, As stated before the last Arduino (Pro Mini) this was working just fine after much reading and I swear I cant find the thread again. I came across this one reply showing how to set up a SoftwareSerial port with the one at the end of the pin parameters. Took off flying and reading everything just fine.
2 Days ago I wired up a Mega 2560 board and its been hell sence. The 4D Display not talking to the Mega nor is the scanner. I have double check and found a few wiring errors, but they have been corrected. I can put in code and make the #13 DIO LED blink so it is not a bricked board.
Well if worse comes to worse. I will just put back in SoftwareSerial and set up a few of those comm ports. Seems that the display and bar code scanner worked just fine on those types of ports. Heck the Mega has more than enough Digital pins that are not being used.
As for the spec sheet. Not sure what your looking for. They really dont get into what the signal is like. They sell these to go on cashregisters and inventory devices, not makers projects. When I called, ended up talking to a level 2 tech and he was of no help either.
I just remembered from that post that was so helpful. The Author said something about how the Arduino had some kind of inversion on its Digital pins. I would love to hear from more people who have the Mega 2560 boards.
Thanks for the help