SoftwareSerial on Arduino Nano

Hi all, I'm new in the fantastic Arduino world. I'd like know because this example: doesn't work on my Nano. I try: 1) connect pins 10 and 11 with a 10Kohm resistor; 2) jumped pins 10 and 11; 3) leave pins 10 and 11 free;

But all I had is only "Goodnight moon!" message in serial monitor. Not "Hello, world?"!

Thank's in advance.

The Serial Monitor shows what is send via hardware serial.

To see what is send via softwareserial (pin11), you have to connect a serial/usb adapter to that pin.
If you have another Arduino you can use that as serial/usb converter

Hi Herni, thank's for you reply. I don't undestand... when something come out from pin11 (TX) throught the loopback come in from pin10 (RX), so datas are available on software serial port. Then sketch read this datas and write it to hardware serial port (direct to serial monitor). Isn't what do the sketch in the example?

SoftwareSerial mySerial(10, 11); // RX, TX

void setup()  
  // Open serial communications and wait for port to open:
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only

  Serial.println("Goodnight moon!");

  // set the data rate for the SoftwareSerial port
  mySerial.println("Hello, world?");

void loop() // run over and over
  if (mySerial.available())
  if (Serial.available())

NOTE: I've connect pin 10 and 11 (with a resistor in first case, jumped in second case) in my arduino nano.

I think I read somewhere that SofwareSerial can't write and read at the same time so the loopback may not be working.

The example assumes you have two separate Arduinos.


Thanks Robin... you think right! :) But I see that example, so.... I miss the assumption that it works with two Arduino :blush: Now is all clear. Thanks

hi for my project I need to use RX port to receive data from the sensor & parallelly I'm using sd card also.

the main task is to synchronise both but due to rx pin from the sensor I'm getting an error called programmer is not responding

when I remove the rx pin from the board, there is no such error


@kammatisai, this Thread was 6 years dead.

And you have had a reply to the same question in your own Thread



when you write 'jumped' do you mean with a wire?

Isn't it risky to directly connect one port to another without a resistor to limit the current?


Peterd51: Isn't it risky to directly connect one port to another without a resistor to limit the current?

Only if both pins are configured as output. Pins configured as input draw minimal current (so-called input leakage (datasheet Iil and Iih)). A pin used as TX is an output, a pin used as RX is an input.




AS i'm using arduino UNO board i found this.

What exactly is "this" ?


How about just pursuing this subject in your own Thread rather than in this ancient Thread?