Pro Mini board question

Development Other Hardware Development
1

Hi,

I have a question about the Pro Mini Arduino board:
This board have 2 pins named TXI and RXO.
I already used them to connect (for example) the Tx pin of a gps to the RXI (of the Pro Mini board) to receive and read GPS data.

But now I need to connect a Uart Tx and Rx pins of a Gsm module to the Pro Mini board.
Can I use the TXI and RXO pins of the Pro Mini board as Uart ?

Thanks for help.

2

RX/TX are UART pins. UART is in Arduino sketches accessible over object called Serial

3

Thanks for reply,
Do you know if it is a software o hardware Uart port??
What can I do if I need more than one Uart port?

4

Serial is instance of HardwareSerial and pins 0 and 1 are hardware serial on every 8-bit Atmega microcontroller.

5

If you need a 2nd serial port., you can use one of the Software Serial libraries for slower speed interfaces, or you can step up to a uC with two ports (1284P) or 4 ports (2560).
I offer small formfactor boards for both.
http://www.crossroadsfencing.com/BobuinoRev17/

6

Thanks for the offer CrossRoad, but I need to mantein the size of project "very small".
I tried to connect the Gsm module to pin TX & RX (hardware serial) of the Pro Mini board, but I found some difficulty to make the connection correctly working.
I read in somewhere that the hardware port is used also by the FTDI module to communicate with the board.
Then I used the software port (pin 10,11) of the Pro Mini board to connect the Gsm module and it seems to work correctly.
Then it means that the hardware port is practically unusable?

7

Do you need the FTDI connected in final setup?

8

No, I use the FTDI only for develop software....

9

then you have a free hardware serial in final setup :-). develop with software serial and for final setup use hardware serial.

and you can use the FTDI adapter with SoftwareSerial on some pair of pins for debug prints in final setup. (lock-out for common grounding)

10

Thanks Juraj, your support is been very useful.
From your answer I understtod that if I need, I'll can to add a 2nd serial port in the Pro Mini board.
Do I understood well?

11

you have one hw uart if you do not use it for usb. and you can use some sw serial library for more serial connections

12

Can I create /use more than one sw port on the pro mini?

13

with SoftwareSerial library yes. better soft serial libraries exist, some of the are specialized for defined pair of pins