SoftwareSerial problems for alternative arduino mega

I am using Robotdyn mega 2560 pro (embed) and softwareserial library for designating another tx rx pins for my ttl-rs232 connector.

Here is my code for tx rx:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(15, 14); //rx tx pins

For the setup, i will only write the serial begins since other codes are for nextion hmi.

void setup(void){

Serial.begin(9600);
mySerial.begin(9600);
nexSerial.begin(9600); //for nextion hmi
}

for the loop, i only used nexLoop for the nextion hmi touch events.

I tried connecting the rx tx pins of nextion hmi at the assigned softwareserial 15 and 14 pins for testing purposes but it doesn’t work. I tried connecting the nextion hmi pins again at the original rx tx pins which are pins 0 and 1 and it worked. What seems to be the problem? I also tried using other pins such as 10, 11 or 19, 18 but it still doesn’t work.

Here is the specifications for the robotdyn mega 2560

Is there a particular reason why you are using SoftwareSerial on one of the Mega's hardware serial ports (Serial3), using hardware serial would normally be a far better idea ?

Having said that SoftwareSerial should work, but if you want help you will need to reveal what you mean by 'doesn't work' (the forum cannnot know) and post all the code you are using.

Suggest you read the 'How to use this forum - please read' post at the top of the forum and provide the information suggested.

Already solved. Thank you for helping
I was using Serial 1 for nextion but the tx and rx pins are for Serial3. I changed Serial1 to Serial3 at the nexConfig.h file

AnIntern:
Already solved. Thank you for helping
I was using Serial 1 for nextion but the tx and rx pins are for Serial3. I changed Serial1 to Serial3 at the nexConfig.h file

There is a common saying on here; "The problem is in the code you did not post"