BLYNK
HOME       📲 GETTING STARTED       📗 DOCS       ❓HELP CENTER       👉 SKETCH BUILDER

My SIM900 modem cannot init

Hi guys. I have an big issue when I started trying to use the SIM900 with Blynk.
Here is my Code

#define BLYNK_PRINT Serial

// Select your modem:
//#define TINY_GSM_MODEM_SIM800
#define TINY_GSM_MODEM_SIM900
//#define TINY_GSM_MODEM_M590
//#define TINY_GSM_MODEM_A6

// Default heartbeat interval for GSM is 60
// If you want override this value, uncomment and set this option:
//#define BLYNK_HEARTBEAT 30

#include <TinyGsmClient.h>
#include <BlynkSimpleSIM800.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "MYAUTH";

// Your GPRS credentials
// Leave empty, if missing user or pass

char apn[]  = "iliad";
char user[] = "";
char pass[] = "";

// Hardware Serial on Mega, Leonardo, Micro
#define SerialAT Serial1

// or Software Serial on Uno, Nano
#include <SoftwareSerial.h>
SoftwareSerial SerialAT(2, 3); // RX, TX

TinyGsm modem(SerialAT);

void setup()
{
  delay(3000);
  // Debug console
  Serial.begin(9600);

  delay(10);

  // Set GSM module baud rate
  SerialAT.begin(19200);
  delay(3000);

  // Restart takes quite some time
  // To skip it, call init() instead of restart()
  Serial.println("Initializing modem...");
  modem.restart();

  // Unlock your SIM card with a PIN
  //modem.simUnlock("1234");

  Blynk.begin(auth, modem, apn, user, pass);
}

void loop()
{
  Blynk.run();
}

So the code seems to be ok but the output no. Below there is the output:

Initializing modem...
[16253] 
    ___  __          __
   / _ )/ /_ _____  / /__
  / _  / / // / _ \/  '_/
 /____/_/\_, /_//_/_/\_\
        /___/ v0.5.4 on Arduino Uno

[16348] Modem init...
[26614] Cannot init
Initializing modem...
[16254] 
    ___  __          __
   / _ )/ /_ _____  / /__
  / _  / / // / _ \/  '_/
 /____/_/\_, /_//_/_/\_\
        /___/ v0.5.4 on Arduino Uno

[16349] Modem init...
[26615] Cannot init
Initializing modem...

I connected all, also the shared ground. I hope that you can solve this problem.

I’m having the same issue

I’d suggest that you create a new topic and explain in detail the hardware you are using, how it’s connected together, how you are powering your SIM900 (they require a lot of power), the code you are using (correctly formatted with triple backticks of course), and what you are seeing in your serial monitor.

Pete.