SIM800L - repeated commands

Using Arduino Networking, Protocols, and Devices
#1

hi,
i have simple question.

There is a program:

#include <SoftwareSerial.h>
 
SoftwareSerial serialSIM800(8,7);
 
void setup() {
  Serial.begin(9600);
  while(!Serial);
  
  serialSIM800.begin(9600);
   
  Serial.println("start");
}
 
void loop() {
  
  if(serialSIM800.available()){
    Serial.write(serialSIM800.read());
  }
  
  if(Serial.available()){    
    serialSIM800.write(Serial.read());
  }
  
}

and results on the serial monitor:

start
AT           // repeated command entered in serial monitor

OK
AT+CSQ       // repeated my command

+CSQ: 12,0

OK
AT;anything  // repeated my command

ERROR

My question is: why commented commands are repeated?

#2

anyone?

here is similar post gsm - SIM800L module just repeating data sent via serial - Arduino Stack Exchange
but IMO without proper answer

#3

looks like a command echo setting, check the at command manual :slight_smile:

#4

The Command Echo Mode is probably what you need:
ATE0 ==> echo OFF
ATE1 ==> echo ON

#5

big thanks guys

yes, this is it

#6