Repeat Sending with NB-IoT-GNSS Shield

Hardware Portenta Portenta H7
1

Dear community,

I’m working on an IoT project using the Arduino Portenta H7 Lite Connected and the corresponding NB-IoT-GNSS Shield to build a remote device IoT-Device:

Version: 4.0.10 (Was not able to use 4.1.1 with Arduino IDE => Uploading failed)

I am facing multiple problems implementing the GSM functionalities to suit my project.

I’m trying to implement a measure-send-sleep-cycle where the device gathers data and sends it via TCP to a server and then goes to sleep in a reoccurring circular fashion. See the following code:

void setup() {

  Serial.begin(9600);
  Serial.println(data);
  while(!Serial) {}

  GSM.trace(Serial);
  GSM.setTraceLevel(4);

  Serial.println("Starting Carrier Network registration");
  if(!GSM.begin(pin, apn, username, pass, CATNB, BAND_20 | BAND_19)){
    Serial.println("The board was not able to register to the network...");
    // do nothing forevermore:
    while(1);
  }
}

I simplified my code in the loop to a bare sending of data and receiving. Data are just some bytes of results which should be send to the server.

void loop() {
  Serial.println("\nStarting connection to server...");
  // if you get a connection, report back via serial:
  if (client.connect(server, port)) {
    Serial.println("connected to server");
    client.print(data);
    while (client.read() != -1);
    Serial.println("finished sending.");
  } else {
    Serial.println("unable to connect to server");
  }

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

  Serial.println("disconnecting from server.");
  client.stop();

  Serial.println("Test sleep...");
  delay(30000);
  Serial.println("Wakeup...");
}

The issue is now after tow successful sends, i can not send anymore. How is the correct usage of the GSM Class if i want to send every 10 Minutes a package to a remote server. The Example on the documentation is just a "one time send".