Daniel Lee / Mbed OS mbed-os-example-cellular-le910

This is an example based on mbed-os cellular APIs that demonstrates a TCP or UDP echo transaction with a public echo server.

This code is forked from https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-cellular/

This is an example showing how to use Skywire board with LE910-x module.

In this example, I had used the LE910-EUG module for 4G communication. Mbed OS code wasn't changed for LE910-x, because the Telit' HE910 is included mainline code on Mbed OS already. HE910 and LE910 are most similar. Therefore you can use LE910 via HE910 driver. Please check to configure of mbed_app.json, and initialize code for Skywire board of main.cpp.

Open mbed_app.json, you need to define a UART for the MCU to communicate with the xE910 module.

            "TELIT_HE910.tx"                 : "D1",
            "TELIT_HE910.rx"                 : "D0",
            "TELIT_HE910.provide-default"    : true

If you are using Pelion CM, make the following settings:

            "nsapi.default-cellular-apn"     : "\"stream.co.uk\"",
            "nsapi.default-cellular-username": "\"streamip\"",
            "nsapi.default-cellular-password": "\"streamip\"",

For your information, please see Pelion Connectivity Quick start guide.

320

You can find Skywire sensor shield information though NimbeLink site.

Tested with

  • DISCO_L475VG_IOT01A
  • K64F

1. Import the application into your desktop:

 mbed import https://os.mbed.com/users/Daniel_Lee/code/mbed-os-example-cellular-le910/

 cd mbed-os-example-cellular-le910

2. Compile and program:

mbed compile -t GCC_ARM -m DISCO_L475VG_IOT01A

(supported toolchains : GCC_ARM / ARM / IAR)

3. Download binary to a target board

4. Result

mbed-os-example-cellular


Built: Feb  7 2020, 07:02:27
Starting Skywire board with LE910-EUG Demo...
Waiting for Skywire to Boot...
Wait 15 seconds..
Establishing connection


Connection Established.
TCP: connected with echo.mbedcloudtesting.com server
TCP: Sent 4 Bytes to echo.mbedcloudtesting.com
Received from echo server 4 Bytes


Success. Exiting

Diff: main.cpp

Revision:
6:5678c0b6f74e
Parent:
2:0f644d6045cf
Child:
11:23ea0907186e
--- a/main.cpp	Wed Apr 11 06:30:27 2018 +0100
+++ b/main.cpp	Thu May 10 05:17:02 2018 +0100
@@ -18,6 +18,7 @@
 #include "common_functions.h"
 #include "UDPSocket.h"
 #include "OnboardCellularInterface.h"
+#include "CellularLog.h"
 
 #define UDP 0
 #define TCP 1
@@ -51,65 +52,93 @@
 // Echo server port (same for TCP and UDP)
 const int port = 7;
 
-Mutex PrintMutex;
+static rtos::Mutex trace_mutex;
+
+#if MBED_CONF_MBED_TRACE_ENABLE
+static void trace_wait()
+{
+    trace_mutex.lock();
+}
+
+static void trace_release()
+{
+    trace_mutex.unlock();
+}
+
+static char time_st[50];
+
+static char* trace_time(size_t ss)
+{
+    snprintf(time_st, 49, "[%08llums]", Kernel::get_ms_count());
+    return time_st;
+}
+
+static void trace_open()
+{
+    mbed_trace_init();
+    mbed_trace_prefix_function_set( &trace_time );
+
+    mbed_trace_mutex_wait_function_set(trace_wait);
+    mbed_trace_mutex_release_function_set(trace_release);
+}
+
+static void trace_close()
+{
+    mbed_trace_free();
+}
+#endif // #if MBED_CONF_MBED_TRACE_ENABLE
+
 Thread dot_thread(osPriorityNormal, 512);
 
-#define PRINT_TEXT_LENGTH 128
-char print_text[PRINT_TEXT_LENGTH];
-void print_function(const char *input_string)
+void print_function(const char *format, ...)
 {
-    PrintMutex.lock();
-    printf("%s", input_string);
-    fflush(NULL);
-    PrintMutex.unlock();
+    trace_mutex.lock();
+    va_list arglist;
+    va_start( arglist, format );
+    vprintf(format, arglist);
+    va_end( arglist );
+    trace_mutex.unlock();
 }
 
 void dot_event()
 {
-
     while (true) {
-        wait(4);
+        Thread::wait(4000);
         if (!iface.is_connected()) {
-            print_function(".");
+            trace_mutex.lock();
+            printf(".");
+            fflush(stdout);
+            trace_mutex.unlock();
         } else {
             break;
         }
     }
-
 }
 
-
 /**
  * Connects to the Cellular Network
  */
 nsapi_error_t do_connect()
 {
-    nsapi_error_t retcode;
+    nsapi_error_t retcode = NSAPI_ERROR_OK;
     uint8_t retry_counter = 0;
 
     while (!iface.is_connected()) {
-
         retcode = iface.connect();
         if (retcode == NSAPI_ERROR_AUTH_FAILURE) {
             print_function("\n\nAuthentication Failure. Exiting application\n");
-            return retcode;
-        } else if (retcode != NSAPI_ERROR_OK) {
-            snprintf(print_text, PRINT_TEXT_LENGTH, "\n\nCouldn't connect: %d, will retry\n", retcode);
-            print_function(print_text);
+        } else if (retcode == NSAPI_ERROR_OK) {
+            print_function("\n\nConnection Established.\n");
+        } else if (retry_counter > RETRY_COUNT) {
+            print_function("\n\nFatal connection failure: %d\n", retcode);
+        } else {
+            print_function("\n\nCouldn't connect: %d, will retry\n", retcode);
             retry_counter++;
             continue;
-        } else if (retcode != NSAPI_ERROR_OK && retry_counter > RETRY_COUNT) {
-            snprintf(print_text, PRINT_TEXT_LENGTH, "\n\nFatal connection failure: %d\n", retcode);
-            print_function(print_text);
-            return retcode;
         }
-
         break;
     }
-
-    print_function("\n\nConnection Established.\n");
-
-    return NSAPI_ERROR_OK;
+    return retcode;
 }
 
 /**
@@ -127,17 +156,14 @@
 
     retcode = sock.open(&iface);
     if (retcode != NSAPI_ERROR_OK) {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "UDPSocket.open() fails, code: %d\n", retcode);
-        print_function(print_text);
+        print_function("UDPSocket.open() fails, code: %d\n", retcode);
         return -1;
     }
 
     SocketAddress sock_addr;
     retcode = iface.gethostbyname(host_name, &sock_addr);
     if (retcode != NSAPI_ERROR_OK) {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "Couldn't resolve remote host: %s, code: %d\n", host_name,
-               retcode);
-        print_function(print_text);
+        print_function("Couldn't resolve remote host: %s, code: %d\n", host_name, retcode);
         return -1;
     }
 
@@ -150,21 +176,17 @@
 #if MBED_CONF_APP_SOCK_TYPE == TCP
     retcode = sock.connect(sock_addr);
     if (retcode < 0) {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "TCPSocket.connect() fails, code: %d\n", retcode);
-        print_function(print_text);
+        print_function("TCPSocket.connect() fails, code: %d\n", retcode);
         return -1;
     } else {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "TCP: connected with %s server\n", host_name);
-        print_function(print_text);
+        print_function("TCP: connected with %s server\n", host_name);
     }
     retcode = sock.send((void*) echo_string, sizeof(echo_string));
     if (retcode < 0) {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "TCPSocket.send() fails, code: %d\n", retcode);
-        print_function(print_text);
+        print_function("TCPSocket.send() fails, code: %d\n", retcode);
         return -1;
     } else {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "TCP: Sent %d Bytes to %s\n", retcode, host_name);
-        print_function(print_text);
+        print_function("TCP: Sent %d Bytes to %s\n", retcode, host_name);
     }
 
     n = sock.recv((void*) recv_buf, sizeof(recv_buf));
@@ -172,12 +194,10 @@
 
     retcode = sock.sendto(sock_addr, (void*) echo_string, sizeof(echo_string));
     if (retcode < 0) {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "UDPSocket.sendto() fails, code: %d\n", retcode);
-        print_function(print_text);
+        print_function("UDPSocket.sendto() fails, code: %d\n", retcode);
         return -1;
     } else {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "UDP: Sent %d Bytes to %s\n", retcode, host_name);
-        print_function(print_text);
+        print_function("UDP: Sent %d Bytes to %s\n", retcode, host_name);
     }
 
     n = sock.recvfrom(&sock_addr, (void*) recv_buf, sizeof(recv_buf));
@@ -186,8 +206,7 @@
     sock.close();
 
     if (n > 0) {
-        snprintf(print_text, PRINT_TEXT_LENGTH, "Received from echo server %d Bytes\n", n);
-        print_function(print_text);
+        print_function("Received from echo server %d Bytes\n", n);
         return 0;
     }
 
@@ -196,28 +215,38 @@
 
 int main()
 {
-
-    iface.modem_debug_on(MBED_CONF_APP_MODEM_TRACE);
+    print_function("\n\nmbed-os-example-cellular\n");
+    print_function("Establishing connection\n");
+#if MBED_CONF_MBED_TRACE_ENABLE
+    trace_open();
+#else
+    dot_thread.start(dot_event);
+#endif // #if MBED_CONF_MBED_TRACE_ENABLE
     /* Set Pin code for SIM card */
     iface.set_sim_pin(MBED_CONF_APP_SIM_PIN_CODE);
 
-    /* Set network credentials here, e.g., APN*/
+    /* Set network credentials here, e.g., APN */
     iface.set_credentials(MBED_CONF_APP_APN, MBED_CONF_APP_USERNAME, MBED_CONF_APP_PASSWORD);
 
-    print_function("\n\nmbed-os-example-cellular\n");
-    print_function("Establishing connection ");
-    dot_thread.start(dot_event);
+    /* Set the modem debug on/off */
+    iface.modem_debug_on(MBED_CONF_APP_MODEM_TRACE);
+
+    nsapi_error_t retcode = NSAPI_ERROR_NO_CONNECTION;
 
     /* 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) {
-            print_function("\n\nSuccess. Exiting \n\n");
-            return 0;
-        }
+        retcode = test_send_recv();
     }
 
-    print_function("\n\nFailure. Exiting \n\n");
-    return -1;
+    if (retcode == NSAPI_ERROR_OK) {
+        print_function("\n\nSuccess. Exiting \n\n");
+    } else {
+        print_function("\n\nFailure. Exiting \n\n");
+    }
+#if MBED_CONF_MBED_TRACE_ENABLE
+    trace_close();
+#endif // #if MBED_CONF_MBED_TRACE_ENABLE
+
+    return 0;
 }
 // EOF