NB MKR1500 example [ugly]

mkrnb_holo_jumper.ino

/*
 Hologram Demo - GSM Network Jumping
 This example shows how to switch between carriers using a Hologram SIM. 
 Circuit:
 * MKR NB 1500 board
 * Antenna
 * Hologram SIM card
 Created 12 Dec 2018
 by Benstr
*/

// libraries
#include <MKRNB.h>

// initialize the library instance
NB nbAccess('true');     // include a 'true' parameter to enable debugging
NBScanner scannerNetworks;
NBModem modemTest;
GPRS gprs;
NBClient client;

// Webserver Variables
char server[] = "arduino.cc";
char path[] = "/asciilogo.txt";
int port = 80;

// Carriar Codes
String ATT_MNC = "310410";
String VER_MNC = "311480";
String TMO_MNC = "310260";

// Save data variables
String IMEI = "";

// connection state
bool connected = false;

// baud rate used for both Serial ports
unsigned long baud = 115200;

void setup() {
  // Reset the ublox module
  modemTest.begin();

  // Eat your Serial
  Serial.begin(baud);
  SerialSARA.begin(baud);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }

  Serial.println("Hologram MKR1500 Network Jumper");

  scannerNetworks.begin();

  // Get modem unique identifier
  Serial.print("Modem IMEI: ");
  IMEI = modemTest.getIMEI();
  IMEI.replace("\n", "");
  if (IMEI != NULL) {
    Serial.println(IMEI);
  }

  delay(3000);

  //printCarrierInfo();

  Serial.println("Pick an available network by typing one of the following:");
  Serial.println("\"att\": AT&T LTE-M/CAT-M1 (MNC 310-410)");
  Serial.println("\"verizon\": Verizon LTE-M/CAT-M1 (MNC 311-480)");
  Serial.println("\"tmobile\": T-Mobile NB-IoT (MNC 310-260)");
}

void loop() {
  // if there are incoming bytes available
  // from the server, read them and print them:
  while (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  while (SerialSARA.available()) {
    Serial.print(SerialSARA.read());
  }
  
  if (Serial.available()) {
    String command = Serial.readString();
    //Serial.print(command);

    if (command.indexOf("att") >= 0) 
    {
      Serial.println();
      Serial.println("Jumping to AT&T LTE-M");
      jumpCarrier(String("AT+COPS=1,2,"+ATT_MNC+",8\r\n"));
      get_arduinocc();
    } 
    else if (command.indexOf("ver") >= 0)
    {
      Serial.println();
      Serial.println("Jumping to Verizon LTE-M");
      jumpCarrier(String("AT+COPS=1,2,"+VER_MNC+",8\r\n"));
      get_arduinocc();
    }
    else if (command.indexOf("tmo") >= 0)
    {
      Serial.println();
      Serial.println("Jumping to T-Mobile NB-IoT");
      jumpCarrier(String("AT+COPS=1,2,"+TMO_MNC+",9\r\n"));
    }
    else if (command.indexOf("netz") >= 0)
    {
      Serial.println();
      // scan for existing networks, displays a list of networks
      Serial.println("Scanning available networks. May take a few minutes.");
      //scannerNetworks.begin();
      Serial.println(scannerNetworks.readNetworks());
      Serial.println("Network scan complete. If there are no networks scan again.");
    }
    else if (command.indexOf("at+") >= 0 || command.indexOf("AT+") >= 0)
    {
      SerialSARA.write(command.c_str());
    }
  }
}

bool jumpCarrier(String network)
{
  bool good = true;
  do
  {
    Serial.println("jumping from previous network...");
    good = sendGSMCommand(String("AT+CGATT=0\r\n"));
    good = sendGSMCommand(String("AT+COPS=2\r\n"));
    Serial.println("success!");
    
    Serial.println("... jumping to new network");
    good = sendGSMCommand(network);
    good = sendGSMCommand(String("AT+COPS=0\r\n"));
    good = sendCREGCommand(String("AT+CREG?\r\n"));
    good = sendGSMCommand(String("AT+CGATT=1\r\n"));
    //good = sendGSMCommand(String("AT+UPSD=0,1,\"hologram\"\r\n"));
    //good = sendGSMCommand(String("AT+UPSD=0,7,\"0.0.0.0\"\r\n"));
    //good = sendGSMCommand(String("AT+UPSDA=0,3\r\n"));
    //good = sendGSMCommand(String("AT+UPSND=0,8\r\n"));
//    if(gprs.attachGPRS("hologram","","")==GPRS_READY){
//      Serial.println("success!");
//      Serial.println();
//      
//      printCarrierInfo();
//      
//      return good;
//    } else {
//      good = false;
//    }
    
  } while(good == false);
  Serial.println("Error when joining");
}

void printCarrierInfo()
{
  // currently connected carrier
  Serial.print("Current carrier: ");
  Serial.println(scannerNetworks.getCurrentCarrier());
  Serial.println();
  // 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(" out of a possible 31");
}

bool sendGSMCommand(String command)
{
  Serial.println(command.c_str());
  SerialSARA.write(command.c_str());

  String response;

  while(!SerialSARA.available()) {
    ;
  }
  
  if(SerialSARA.available())
  {
    response = SerialSARA.readString();
    Serial.println(response);

    if (response.indexOf("OK") >= 0) {
      return true;
    } else {
      return false;  
    }
  }
}

bool sendCREGCommand(String command)
{
  String response;
  
  Serial.println(command.c_str());

  while (response.indexOf("0,5") == -1) {
    SerialSARA.write(command.c_str());

    while(!SerialSARA.available()) {
      ;
    }
    
    if(SerialSARA.available())
    {
      response = SerialSARA.readString();
      Serial.println(response); 
    }

    delay(2000);
  }
  return true;
}

void get_arduinocc() {
  Serial.println("Connecting to Arduino.cc");
  // if you get a connection, report back via serial:
  if (client.connect(server, port)) {
    Serial.println("Connected! Getting file.");
    // Make a HTTP request:
    client.print("GET ");
    client.print(path);
    client.println(" HTTP/1.1");
    client.print("Host: ");
    client.println(server);
    client.println("Connection: close");
    client.println();
    Serial.println("Arduino.cc Connection Complete.");
  } else {
    // if you didn't get a connection to the server:
    Serial.println("Connection failed");
  }  
}