Comunication with module sim800l

[andrealorenzetti123321]

Hello everyone, I am trying to use the arduino module sim800l but when i try to send some at command, like a siple AT, I get in response '???' in loop and I do understand the cause of this.
Another problem is the alimentation of this module that requires 2-3 A when it send messages, for now i would be happy if i can establish a undersandable comunication with it so I didn't put the sim in the slot.
Here is the code that I am using:

#include <SoftwareSerial.h>

SoftwareSerial mySerial(2, 3); // RX, TX 

void setup()  
{
  // Open serial communication
  Serial.begin(9600);

  // set the data rate for the SoftwareSerial port
  mySerial.begin(9600);
  
  Serial.println("Testing SIM800L module");

  delay(1000);

}

void loop() // run over and over
{
  updateSerial();  
}


void updateSerial(){
  delay(500);  
  while( mySerial.available() )
  {
    mySerial.write(Serial.read());
  }
 
  while(Serial.available())
  { 
    Serial.write(mySerial.read());
  }
}

and here are some photos of the connections:

and here is the link of the battery that i am using:
https://www.manomano.it/p/4-batterie-batteria-ricaricabile-ioni-di-litio-6800-mah-37v-bl-18650-torce-led-4856595

[UKHeliBob]

@andrealorenzetti123321

Here is the code that I am using:

Please follow the advice given in the link below when posting code. Use code tags (the </> icon above the compose window) to make it easier to read and copy for examination

How to get the best out of this forum

Hello, Welcome to the Arduino Forum. This guide explains how to get the best out of this forum. Please read and follow the instructions below. Being new here you might think this is having rules for the sake of rules, but that is not the case. If you don’t follow the guidelines all that happens is there is a long exchange of posts while we try to get you to tell us what we need in order to help you, which is frustrating for you and frustrating for us. The people who try to help with your pro…

[andrealorenzetti123321]

sorry i didnt see the button

[UKHeliBob]

Your post was MOVED to its current location as it is more suitable.

[Danois90]

Ooops times two..

while( mySerial.available() ) //Should be Serial.available() ?
  {
    mySerial.write(Serial.read());
  }
 
  while(Serial.available()) //Should be mySerial.available() ?
  { 
    Serial.write(mySerial.read());
  }

[andrealorenzetti123321]

yes thanks a lot you are right, i dont understand how could I miss it, thanks again

[andrealorenzetti123321]

do you know how could i resolve the alimentation problem? i bought this battesies becouse i watched a video on youtube but it doesnt seem working

[330R]

What exactly is the matter with your current battery configuration? Does it work alright with a power supply?

[andrealorenzetti123321]

The led of the module should blink every 3 seconds when it is connected to the sim network but it blinks every seconds and this means that it is trying to connect but it cannot so it restart the attempt of connecting.
I opened a new argoment at this link for this problem : sim800L problems to connecting to the sim network (blinking problem)