TCP socket, and status info

Author: Teemu Kultala

README.md

@@ -49,7 +49,7 @@ See the file `mbed_app.json` in the root directory of your application. This fil
 
 ### Selecting socket type (TCP or UDP)
 
-You can choose which socket type the application should use. For example:
+You can choose which socket type the application should use, however please note that TCP is more reliable tranmission protocol. For example:
 
 ```json
 

main.cpp

@@ -40,6 +40,8 @@
 // Number of retries /
 #define RETRY_COUNT 3
 
+
+
 // CellularInterface object
 OnboardCellularInterface iface;
 
@@ -49,6 +51,33 @@ const char *host_name = "echo.u-blox.com";
 // Echo server port (same for TCP and UDP)
 const int port = 7;
 
+Mutex PrintMutex;
+Thread dot_thread;
+
+#define PRINT_TEXT_LENGTH 128
+char print_text[PRINT_TEXT_LENGTH];
+void print_function(const char *input_string)
+{
+    PrintMutex.lock();
+    printf("%s", input_string);
+    PrintMutex.unlock();
+}
+
+void dot_event()
+{
+
+    while (true) {
+        wait(4);
+        if (!iface.is_connected()) {
+            print_function("Connection not ready...\n");
+        } else {
+            break;
+        }
+    }
+
+}
+
+
 /**
  * Connects to the Cellular Network
  */
@@ -61,21 +90,23 @@ nsapi_error_t do_connect()
 
         retcode = iface.connect();
         if (retcode == NSAPI_ERROR_AUTH_FAILURE) {
-            printf("\n\nAuthentication Failure. Exiting application\n");
+            print_function("\n\nAuthentication Failure. Exiting application\n");
             return retcode;
         } else if (retcode != NSAPI_ERROR_OK) {
-            printf("\n\nCouldn't connect: %d, will retry\n", retcode);
+            snprintf(print_text, PRINT_TEXT_LENGTH, "\n\nCouldn't connect: %d, will retry\n", retcode);
+            print_function(print_text);
             retry_counter++;
             continue;
         } else if (retcode != NSAPI_ERROR_OK && retry_counter > RETRY_COUNT) {
-            printf("\n\nFatal connection failure: %d\n", retcode);
+            snprintf(print_text, PRINT_TEXT_LENGTH, "\n\nFatal connection failure: %d\n", retcode);
+            print_function(print_text);
             return retcode;
         }
 
         break;
     }
 
-    printf("\n\nConnection Established.\n");
+    print_function("\n\nConnection Established.\n");
 
     return NSAPI_ERROR_OK;
 }
@@ -95,49 +126,57 @@ nsapi_error_t test_send_recv()
 
     retcode = sock.open(&iface);
     if (retcode != NSAPI_ERROR_OK) {
-        printf("UDPSocket.open() fails, code: %d\n", retcode);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "UDPSocket.open() fails, code: %d\n", retcode);
+        print_function(print_text);
         return -1;
     }
 
     SocketAddress sock_addr;
     retcode = iface.gethostbyname(host_name, &sock_addr);
     if (retcode != NSAPI_ERROR_OK) {
-        printf("Couldn't resolve remote host: %s, code: %d\n", host_name,
+        snprintf(print_text, PRINT_TEXT_LENGTH, "Couldn't resolve remote host: %s, code: %d\n", host_name,
                retcode);
+        print_function(print_text);
         return -1;
     }
 
     sock_addr.set_port(port);
 
     sock.set_timeout(15000);
     int n = 0;
-    char *echo_string = "TEST";
+    const char *echo_string = "TEST";
     char recv_buf[4];
 #if MBED_CONF_APP_SOCK_TYPE == TCP
     retcode = sock.connect(sock_addr);
     if (retcode < 0) {
-        printf("TCPSocket.connect() fails, code: %d\n", retcode);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "TCPSocket.connect() fails, code: %d\n", retcode);
+        print_function(print_text);
         return -1;
     } else {
-        printf("TCP: connected with %s server\n", host_name);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "TCP: connected with %s server\n", host_name);
+        print_function(print_text);
     }
     retcode = sock.send((void*) echo_string, sizeof(echo_string));
     if (retcode < 0) {
-        printf("TCPSocket.send() fails, code: %d\n", retcode);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "TCPSocket.send() fails, code: %d\n", retcode);
+        print_function(print_text);
         return -1;
     } else {
-        printf("TCP: Sent %d Bytes to %s\n", retcode, host_name);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "TCP: Sent %d Bytes to %s\n", retcode, host_name);
+        print_function(print_text);
     }
 
     n = sock.recv((void*) recv_buf, sizeof(recv_buf));
 #else
 
     retcode = sock.sendto(sock_addr, (void*) echo_string, sizeof(echo_string));
     if (retcode < 0) {
-        printf("UDPSocket.sendto() fails, code: %d\n", retcode);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "UDPSocket.sendto() fails, code: %d\n", retcode);
+        print_function(print_text);
         return -1;
     } else {
-        printf("UDP: Sent %d Bytes to %s\n", retcode, host_name);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "UDP: Sent %d Bytes to %s\n", retcode, host_name);
+        print_function(print_text);
     }
 
     n = sock.recvfrom(&sock_addr, (void*) recv_buf, sizeof(recv_buf));
@@ -146,36 +185,37 @@ nsapi_error_t test_send_recv()
     sock.close();
 
     if (n > 0) {
-        printf("Received from echo server %d Bytes\n", n);
+        snprintf(print_text, PRINT_TEXT_LENGTH, "Received from echo server %d Bytes\n", n);
+        print_function(print_text);
         return 0;
     }
 
     return -1;
-
-    return retcode;
 }
 
 int main()
 {
+
     iface.modem_debug_on(MBED_CONF_APP_MODEM_TRACE);
     /* Set Pin code for SIM card */
     iface.set_sim_pin(MBED_CONF_APP_SIM_PIN_CODE);
 
     /* Set network credentials here, e.g., APN*/
     iface.set_credentials(MBED_CONF_APP_APN, MBED_CONF_APP_USERNAME, MBED_CONF_APP_PASSWORD);
 
-    printf("\n\nmbed-os-example-cellular, Connecting...\n");
+    print_function("\n\nmbed-os-example-cellular, Connecting...\n");
+    dot_thread.start(dot_event);
 
     /* Attempt to connect to a cellular network */
     if (do_connect() == NSAPI_ERROR_OK) {
         nsapi_error_t retcode = test_send_recv();
         if (retcode == NSAPI_ERROR_OK) {
-            printf("\n\nSuccess. Exiting \n\n");
+            print_function("\n\nSuccess. Exiting \n\n");
             return 0;
         }
     }
 
-    printf("\n\nFailure. Exiting \n\n");
+    print_function("\n\nFailure. Exiting \n\n");
     return -1;
 }
 // EOF

mbed_app.json

@@ -1,6 +1,6 @@
 {
     "config": {
-        "sock-type": "UDP",
+        "sock-type": "TCP",
         "modem_trace": {
             "help": "Turns AT command trace on/off from the cellular modem, defaults to off",
             "value": false
@@ -34,4 +34,4 @@
             "platform.default-serial-baud-rate": 115200
         }
     }
-}
+}