TinyGSM gprs and lte connection clarification

[awneil]

@jbejaranoq

  SerialAT.println("AT+CEREG?");
  delay(500);
  if (SerialAT.available()){
    String input = SerialAT.readString();
    Serial.printf("CEREG?: %s \n",input.c_str());
  }

Don't rely on blind delays:

AT Command Guide for SIM 800/900 modules

Questions that come up related to SIM 800/900 modules often use single Serial.println("AT_COMMAND_EXAMPLE"); lines for AT command execution, usually delays inserted between them and not checking the response for each command at all! As different commands execution time can vary greatly and each response from the module contains valuable information, this is far from reliable communication with such modules. Furthermore one particular command can take very different times, for example establishi…