NB Scan Networks

This example prints out the IMEI number of the modem, then checks to see if it's connected to a carrier and prints out its signal strength. It also scans for all nearby networks.

Hardware Required

Circuit

MKRNB1500 bb

Code

First, import the NB library

#include <MKRNB.h>

SIM cards may have a PIN number that enables their functionality. Define the PIN for your SIM. If your SIM has no PIN, you can leave it blank :

#define PINNUMBER ""

Initialize instances of the classes you're going to use. You're going to need the NB, NBScanner, and NBModem classes.

NB nbAccess;

NBScanner scannerNetworks;

NBModem modemTest;

Create a variable to hold the IMEI number, and a status messages to send to the serial monitor:

String IMEI = "";

String errortext = "ERROR";

In setup, open a serial connection to the computer. After opening the connection, send a message to the Serial Monitor indicating the sketch has started. Call @scannerNetworks.begin()@@ to reset the modem.

void setup(){

  Serial.begin(9600);

  Serial.println("NB networks scanner");

  scannerNetworks.begin();

Create a local variable to track the connection status. You'll use this to keep the sketch from starting until the SIM is connected to the network :

boolean connected = true;

Connect to the network by calling gsmAccess.begin(). It takes the SIM card's PIN as an argument. By placing this inside a while() loop, you can continually check the status of the connection. When the modem does connect, nbAccess() will return NB_READY. Use this as a flag to set the connected variable to true or false. Once connected, the remainder of setup will run.

while(!connected)

  {

    if ((nbAccess.begin(PINNUMBER) == GSM_READY) &&

       (gprs.attachGPRS() == GPRS_READY)) {

     connected = true;

    else

    {

      Serial.println("Not connected");

      delay(1000);

    }

  }

Get the IMEI of the modem with modemTest.getIMEI() and print it out to the serial monitor.

Serial.print("Modem IMEI: ");

  IMEI = modemTest.getIMEI();

  IMEI.replace("\n","");

  if(IMEI != NULL)

    Serial.println(IMEI);

In loop(), scan and print out all available networks. This may take some time

Serial.println("Scanning available networks. May take some seconds.");

  Serial.println(scannerNetworks.readNetworks());

Print out the current connected carrier, and the strength of the signal. Signal strength is on a scale of 0-31, where 0 is the lowest, and 31 is the highest. close the loop().

Serial.print("Current carrier: ");

  Serial.println(scannerNetworks.getCurrentCarrier());

  Serial.print("Signal Strength: ");

  Serial.print(scannerNetworks.getSignalStrength());

  Serial.println(" [0-31]");

Once your code is uploaded, open the serial monitor to see the status of the connection.

The complete sketch is below.


/*

 NB Scan Networks

 This example prints out the IMEI number of the modem,

 then checks to see if it's connected to a carrier.

 Then it scans for nearby networks and prints out their signal strengths.

 Circuit:

 * MKR NB 1500 board

 * Antenna

 * SIM card

 Created 8 Mar 2012

 by Tom Igoe, implemented by Javier Carazo

 Modified 4 Feb 2013

 by Scott Fitzgerald

*/

// libraries
#include <MKRNB.h>

#include "arduino_secrets.h"
// Please enter your sensitive data in the Secret tab or arduino_secrets.h
// PIN Number

const char PINNUMBER[] = SECRET_PINNUMBER;

// initialize the library instance

NB nbAccess;     // include a 'true' parameter to enable debugging

NBScanner scannerNetworks;

NBModem modemTest;

// Save data variables

String IMEI = "";

// serial monitor result messages

String errortext = "ERROR";

void setup() {

  // initialize serial communications and wait for port to open:

  Serial.begin(9600);

  while (!Serial) {

    ; // wait for serial port to connect. Needed for Leonardo only

  }

  Serial.println("NB IoT/LTE Cat M1 networks scanner");

  scannerNetworks.begin();

  // connection state

  boolean connected = false;

  // Start module

  // If your SIM has PIN, pass it as a parameter of begin() in quotes

  while (!connected) {

    if (nbAccess.begin(PINNUMBER) == NB_READY) {

      connected = true;

    } else {

      Serial.println("Not connected");

      delay(1000);

    }

  }

  // get modem parameters

  // IMEI, modem unique identifier

  Serial.print("Modem IMEI: ");

  IMEI = modemTest.getIMEI();

  IMEI.replace("\n", "");

  if (IMEI != NULL) {

    Serial.println(IMEI);

  }
}

void loop() {

  // currently connected carrier

  Serial.print("Current carrier: ");

  Serial.println(scannerNetworks.getCurrentCarrier());

  // returns strength and ber

  // signal strength in 0-31 scale. 31 means power > 51dBm

  // BER is the Bit Error Rate. 0-7 scale. 99=not detectable

  Serial.print("Signal Strength: ");

  Serial.print(scannerNetworks.getSignalStrength());

  Serial.println(" [0-31]");

  // scan for existing networks, displays a list of networks

  Serial.println("Scanning available networks. May take some seconds.");

  Serial.println(scannerNetworks.readNetworks());

  // wait ten seconds before scanning again

  delay(10000);
}

See Also:

Last revision 2019/04/22 by SM