Planning to use two GPS in my system. Do you think it would work? It's either two GPS shield with SD card or 1 GPS shield with SD card + 1 GPS module on its own. The links are shown below.
I'm worried about using the same pins for both and the signals getting interfered (e.g. tx rx pins).
I’m worried about using the same pins for both and the signals getting interfered (e.g. tx rx pins).
That’s correct, you cannot connect three serial devices together (Arduino, GPS1 and GPS2). Serial is only for connecting two devices. You would need to use two more pins to connect the Arduino to GPS2. You could use Rx1 and Tx1 if you have a Meg2560, or two other pins (e.g., 8 and 9) if you have an UNO.
But… why would you connect two GPS devices? If you searched for other projects with two GPS devices, you may have wondered why you didn’t find any. That’s because it’s not really useful. I suppose if you were comparing one GPS to another, it might be useful.