Retry connection to network for sandbox

Author: M65649

examples/sandbox/sandbox.ino

@@ -109,8 +109,9 @@ void connectLTE() {
 
     Lte.onConnectionStatusChange(connectedToNetwork, disconnectedFromNetwork);
 
-    // Start LTE modem and wait until we are connected to the operator
-    Lte.begin();
+    // Start LTE modem and wait until we are connected to the operator.
+    // If initialization fails, we just retry in the loop
+    while (!Lte.begin()) {}
 }
 
 void startStreamTimer() {

src/lte.cpp

@@ -70,7 +70,7 @@ static void connectionStatus(char *buffer) {
     }
 }
 
-void LteClass::begin(void) {
+bool LteClass::begin(void) {
 
     // If low power is utilized, sequans controller will already been
     // initialized, so don't reset it by calling begin again
@@ -104,7 +104,7 @@ void LteClass::begin(void) {
     if (result != ResponseResult::OK) {
         Log.error("Checking SIM status failed, is the SIM card inserted?");
         SequansController.retryCommand(AT_COMMAND_DISCONNECT);
-        return;
+        return false;
     }
 
     char sim_status[16] = "";
@@ -114,14 +114,14 @@ void LteClass::begin(void) {
 
         Log.error("Failed to extract value from command response during SIM "
                   "status check");
-        return;
+        return false;
     }
 
     // strncmp returns 0 if the strings are equal
     if (strncmp(sim_status, "READY", 5)) {
         Log.errorf("SIM card is not ready, error: %s\r\n", sim_status);
         SequansController.retryCommand(AT_COMMAND_DISCONNECT);
-        return;
+        return false;
     }
 
     // Enable the default callback
@@ -134,6 +134,8 @@ void LteClass::begin(void) {
     if (isConnected() && connected_callback != NULL) {
         connected_callback();
     }
+
+    return true;
 }
 
 void LteClass::end(void) {

src/lte.h

@@ -28,8 +28,10 @@ class LteClass {
     /**
      * @brief Initializes the LTE module and its controller interface. Starts
      * searching for operator.
+     *
+     * @return True if initialization was successful.
      */
-    void begin(void);
+    bool begin(void);
 
     /**
      * @brief Disables the interface with the LTE module. Disconnects from