Can't get software serial to work

Question

So I have two Arduinos (Arduino Nano) and I'm trying to get them to communicate via SoftwareSerial. I have the 'sending' Arduino's D10 pin connected to the 'recieving' Arduino's D11 pin, and vice versa. On my sending Arduino, I have the following code:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11);

void setup() {
  pinMode(2, OUTPUT);
  mySerial.begin(9600);
}

void loop() {
  if (mySerial.isListening()){
    digitalWrite(2, HIGH);
  }
  mySerial.write(5);
}

and on my receiving Arduino, I have:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(11, 10);

void setup() {
  pinMode(2, OUTPUT);

  Serial.begin(9600);

  mySerial.begin(9600);
}

void loop() {
  mySerial.listen();
  if (mySerial.available()>0) {
    digitalWrite(2, HIGH);
    char inByte = mySerial.read();
    Serial.write(inByte);
  }
  digitalWrite(2, LOW);
}

(with D2 being hooked up to an LED for both).

I can't get it to read anything. Nothing seems to be available for the receiving Arduino (the LED is off). What am I doing wrong?

Answer 1

Sender:

SoftwareSerial mySerial(10, 11);  // Rx, Tx

Receiver:

SoftwareSerial mySerial(11, 10);  // Rx, Tx

I have the 'sending' Arduino's D10 pin connected to the 'receiving' Arduino's D11 pin, and vice versa.

So you have the sending Arduino's Rx connected to the receiving Arduino's Rx. Therefore it won't work. You need to connect Rx to Tx.

---

  mySerial.listen();

You don't need that in this simple example.

Answer 2

I agree with Nick above but want to add this simplify your code like this:

if (mySerial.available()) {
    digitalWrite(2, HIGH);    
    Serial.write(mySerial.read());
  }

I have had to catch serial data from a printer feed before and this turned out to be the best way to catch all the data if you place it in a variable first it has to change the variable every time that you receive a byte but this way it places all in a buffer then sends it out

BTW I had to save to a F-RAM device and that worked the same way but instead of sending it I had it saved to a variable while using ReadString() in stead of read().