Arduino Mega 2560 with SIM808 module

I have a SIM808 module like this: https://www.banggood.com/SIM808-Module-GPS-GSM-GPRS-Quad-band-Development-Board-For-Arduino-p-1063106.html

The output header has 5 pins: GND/RX/GND/TX/VCC and I connected them as:

GND/VCC to a LiPo battery, 7.4V@1000mAh

RX->pin 14 (written on it TX3)

GND->to arduino GND

TX->pin 15 (written on it RX3)

and uploaded this code

#include <SoftwareSerial.h>


SoftwareSerial GSMSerial(15,14);    // RX, TX

void setup()
{

  GSMSerial.begin(19200);
  Serial.begin(19200);
  Serial.println("START");
}

void loop()
{
  if(Serial.available())
    GSMSerial.print((char)Serial.read());
  else  if(GSMSerial.available())
    Serial.print((char)GSMSerial.read());
}

But I’m not getting anything on it (when sending “AT” or anything else).

Any help is appreciated.

Thank you!

But I'm not getting anything on it (when sending "AT" or anything else).

Why are you doing SoftwareSerial on the hardware serial pins?

Really good question :slight_smile: Thanks for the hint. It works now (after your reply and reading about the difference between them).

please give me success code