Serial Port Error- Serial write to one port transmitts to all ports

Community General Discussion
1

Hello, Thank You for your attention,

IDE: 2.3.2      Board: NANO      Code:

#include <SoftwareSerial.h>      // USE HW PINS FOR ASYNC COM
SoftwareSerial serial2(2, 1);       // SoftwareSerial(rxPin, txPin)

void setup() {
      serial2.begin(9600);      // START USB FTDI ASYNC COM
      while (!serial2) { ; }        // DELAY FOR STARTUP
      serial2.println("FTDI DONGLE STARTED");

      Serial.begin(9600);      // START HW USB UART  DEBUG ONLY
      while (!Serial) { ; }        // DELAY FOR STARTUP
      Serial.println("MONITOR STARTED");
}

void loop() {}

PROBLEM:
I have an FTDI USB async serial dongle connected to serial2 on PC COM19.
The IDE is on PC COM20.
On startup, the NANO transmits both strings on both ports, unwanted multi-casting!!!
I thought at first the IDE Monitor watches all ports but research suggested this was not an ability of the monitor. Plus, it didn't explain the remote serial2 port.
I closed the IDE and confirmed the problem using RealTerm and Putty.
Anyone have any thoughts.......... Thank You Very Much

2

Pin 1 on a Nano (328P board) is the Tx pin used by hardware Serial.

You have also defined software serial2 to use the same pin.

Use other pins for your software serial object.

3

Thank You so much..... I've been chasing this for over an hour and missed that fact. I knew it was my error but couldn't figure it out. Thank You again..........