Arduino Software Serail testcode

arduino_SoftwareSerial.ino

#include <SoftwareSerial.h>

SoftwareSerial ss(8, 2); // RX, TX

void setup() {
  Serial.begin(115200);
  Serial.println("Goodnight moon!");

  ss.begin(115200);
  ss.println("Hello, world?");
}

unsigned long current_time;
unsigned long timer[2] = {0};
int freq = 1;

#define ECHO 0
#define FREQ 0

void loop() {

#ifdef ECHO
  if (ss.available())
  {
    Serial.write(ss.read());
  }
  if (Serial.available())
  {
    ss.write(Serial.read());
  }
#endif


#ifdef FREQ
  if (ss.available())
  {
    Serial.write(ss.read());
  }
  if (Serial.available())
  {
    freq = Serial.parseInt();
    Serial.print("Freq : ");
    Serial.println(freq);
  }

  current_time = millis();
  if (current_time - timer[0] > int(1000 / freq))
  {
    timer[0] = current_time;
    char ch = 'a';
    ss.write(ch);
  }
#endif
}