I am making a project door lock system with fingerprint sensor and bluetooth module but both use rx and tx how can i use both of them in one arduino board. please help me.
You can try the AltSoftSerial library that emulates a second serial interface. I strongly recommend against the SoftwareSerial library. With that one you can use any pin on the Arduino board for the second serial interface (with AltSoftSerial the pins are fixed) but the price is that interrupts are blocked for very long periods of time which influences other code parts and lead to race conditions very difficult to debug.
pylon:
You can try the AltSoftSerial library that emulates a second serial interface. I strongly recommend against the SoftwareSerial library.
+1
NeoSWSerial is almost as good. It can use any two pins, but only at 9600, 19200 and 38400. It's also available from the Library Manager, under the menu Sketch -> Include Library -> Manage Libraries.
NeoSWSerial is almost as good. It can use any two pins, but only at 9600, 19200 and 38400. It's also available from the Library Manager, under the menu Sketch -> Include Library -> Manage Libraries.
This is an interesting new library. The reception is done much better than in SoftwareSerial but the sending part blocks the CPU for the time the 9 bits need to go out. At least it doesn't disable interrupts in that time frame. So it's very interesting if you have to use a specific pair of pins for your emulated serial interface. If the pins are not fixed yet I prefer AltSoftSerial, although you seem to have a similar library (NeoICSerial) that does the same. Good work, thanks for the effort!
And the Mega has 4 hardware serial ports so its a good choice for talking to several serial devices,
but costs more.