This is an example based on mbed-os cellular APIs that demonstrates a TCP or UDP echo transaction with a public echo server. Included TPB23 NB-IoT module which is can use LGU+ in Korea.

This example is showing how to use the NB-IoT(SECOM TPB23 module) of LGU plus network in Korea. The NB-IoT module' seller provided a document on how to start based on Mbed OS 5.11. (Created by CodeZoo) This guide has been supported to the latest os version which included 5.12 ~ 5.15.

  • if you need specific version of Mbed OS, please revision of TPB23_Driver and check it out.
  • Pelion ready example code is here!

Requirement

462 320 320

320

Tested with

1. Import the application into your desktop

mbed import http://os.mbed.com/users/Daniel_Lee/code/mbed-os-example-cellular-TPB23/

cd mbed-os-example-cellular-TPB23

2. Compile and program

mbed compile -t <toolchain> -m <TARGET_BOARD>

(supported toolchains : GCC_ARM / ARM / IAR)

3. Download binary to a target board

4. Result

mbed-os-example-cellular


Built: Aug  7 2019, 06:10:47


[MAIN], plmn: NULL
Establishing connection
[00000001ms][INFO][CELL]: New CellularContext  (20000a08)
[00000002ms][INFO][CELL]: CellularContext plmn NULL
[00000003ms][INFO][CELL]: CellularContext connect
[00000036ms][INFO][CELL]: RSSI -69 dBm
[00000036ms][INFO][CELL]: Start connecting (timeout 1 s)
[00000087ms][INFO][CELL]: RSSI -69 dBm
[00000116ms][INFO][CELL]: Modem ready
[00000146ms][INFO][CELL]: RSSI -69 dBm
[00000146ms][INFO][CELL]: Setup SIM (timeout 1 s)
[00001233ms][INFO][CELL]: Looked up APN internet
[00001362ms][ERR ][CELL]: AT error code 50
[00001362ms][WARN][CELL]: Packet domain event reporting set failed!
[00001393ms][INFO][CELL]: RSSI -65 dBm
[00001393ms][INFO][CELL]: Network registration (timeout 180 s)
[00001443ms][INFO][CELL]: Registering network => Attaching network
[00001473ms][INFO][CELL]: RSSI -65 dBm
[00001473ms][INFO][CELL]: Attaching network (timeout 60 s)
[00001601ms][INFO][CELL]: Found PDP context 1
[00001649ms][INFO][CELL]: Activate PDP context 1


Connection Established.
[00001671ms][INFO][CELL]: Socket 0 open
[00001707ms][INFO][CELL]: Socket 1 open
[00001748ms][INFO][CELL]: Socket create id: 1
[00001883ms][INFO][CELL]: Socket 1 sent 43 bytes to 8.8.8.8 port 53
[00004311ms][INFO][CELL]: Socket 1 recv 59 bytes from 8.8.8.8 port 53
[00004331ms][INFO][CELL]: Close socket: 1 error: 0
[00004331ms][INFO][CELL]: Socket 1 closed
[00004373ms][INFO][CELL]: Socket create id: 1
TCP: connected with echo.mbedcloudtesting.com server
[00004448ms][INFO][CELL]: Socket 0 sent 4 bytes to 52.215.34.155 port 7
TCP: Sent 4 Bytes to echo.mbedcloudtesting.com
[00007560ms][INFO][CELL]: Socket 0 recv 4 bytes
[00007580ms][INFO][CELL]: Close socket: 1 error: 0
[00007580ms][INFO][CELL]: Socket 0 closed
Received from echo server 4 Bytes
[00007581ms][INFO][CELL]: CellularContext disconnect()
[00007630ms][INFO][CELL]: cb: CellularContext disconnected


Success. Exiting

main.cpp

Committer:
mbed_official
Date:
2018-03-09
Revision:
2:0f644d6045cf
Parent:
0:4611f6cf2413
Child:
6:5678c0b6f74e

File content as of revision 2:0f644d6045cf:

/*
 * Copyright (c) 2017 ARM Limited. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 * Licensed under the Apache License, Version 2.0 (the License); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "mbed.h"
#include "common_functions.h"
#include "UDPSocket.h"
#include "OnboardCellularInterface.h"

#define UDP 0
#define TCP 1

// SIM pin code goes here
#ifndef MBED_CONF_APP_SIM_PIN_CODE
# define MBED_CONF_APP_SIM_PIN_CODE    "1234"
#endif

#ifndef MBED_CONF_APP_APN
# define MBED_CONF_APP_APN         "internet"
#endif
#ifndef MBED_CONF_APP_USERNAME
# define MBED_CONF_APP_USERNAME    NULL
#endif
#ifndef MBED_CONF_APP_PASSWORD
# define MBED_CONF_APP_PASSWORD    NULL
#endif

// Number of retries /
#define RETRY_COUNT 3



// CellularInterface object
OnboardCellularInterface iface;

// Echo server hostname
const char *host_name = "echo.mbedcloudtesting.com";

// Echo server port (same for TCP and UDP)
const int port = 7;

Mutex PrintMutex;
Thread dot_thread(osPriorityNormal, 512);

#define PRINT_TEXT_LENGTH 128
char print_text[PRINT_TEXT_LENGTH];
void print_function(const char *input_string)
{
    PrintMutex.lock();
    printf("%s", input_string);
    fflush(NULL);
    PrintMutex.unlock();
}

void dot_event()
{

    while (true) {
        wait(4);
        if (!iface.is_connected()) {
            print_function(".");
        } else {
            break;
        }
    }

}


/**
 * Connects to the Cellular Network
 */
nsapi_error_t do_connect()
{
    nsapi_error_t retcode;
    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);
            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;
}

/**
 * Opens a UDP or a TCP socket with the given echo server and performs an echo
 * transaction retrieving current.
 */
nsapi_error_t test_send_recv()
{
    nsapi_size_or_error_t retcode;
#if MBED_CONF_APP_SOCK_TYPE == TCP
    TCPSocket sock;
#else
    UDPSocket sock;
#endif

    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);
        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);
        return -1;
    }

    sock_addr.set_port(port);

    sock.set_timeout(15000);
    int n = 0;
    const char *echo_string = "TEST";
    char recv_buf[4];
#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);
        return -1;
    } else {
        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) {
        snprintf(print_text, PRINT_TEXT_LENGTH, "TCPSocket.send() fails, code: %d\n", retcode);
        print_function(print_text);
        return -1;
    } else {
        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) {
        snprintf(print_text, PRINT_TEXT_LENGTH, "UDPSocket.sendto() fails, code: %d\n", retcode);
        print_function(print_text);
        return -1;
    } else {
        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));
#endif

    sock.close();

    if (n > 0) {
        snprintf(print_text, PRINT_TEXT_LENGTH, "Received from echo server %d Bytes\n", n);
        print_function(print_text);
        return 0;
    }

    return -1;
}

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);

    print_function("\n\nmbed-os-example-cellular\n");
    print_function("Establishing connection ");
    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) {
            print_function("\n\nSuccess. Exiting \n\n");
            return 0;
        }
    }

    print_function("\n\nFailure. Exiting \n\n");
    return -1;
}
// EOF