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
- Need to check CodeZoo's s hardware a guide.
- Need a CodeZoo's NBIoT board and development board.
- Board picture & Jumper configure
- And also can use with mbed application shield, as shown below.

Tested with
- DISCO_L475VG_IOT01A - If you are in Korea, can buy here !
- NUCLEO_F429ZI - If you are in Korea, can buy here !
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
Diff: SERCOMM/TPB23/SERCOMM_TPB23_CellularStack.cpp
- Revision:
- 47:006469f922f6
- Parent:
- 46:387c2d922a4a
diff -r 387c2d922a4a -r 006469f922f6 SERCOMM/TPB23/SERCOMM_TPB23_CellularStack.cpp
--- a/SERCOMM/TPB23/SERCOMM_TPB23_CellularStack.cpp Thu Aug 08 08:36:54 2019 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,255 +0,0 @@
-/*
- * Copyright (c) 2017, Arm Limited and affiliates.
- * 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 "SERCOMM_TPB23_CellularStack.h"
-#include "CellularUtil.h"
-#include "CellularLog.h"
-
-#define PACKET_SIZE_MAX 1500 //TPB23 Range is 12-1500
-
-using namespace mbed;
-using namespace mbed_cellular_util;
-
-SERCOMM_TPB23_CellularStack::SERCOMM_TPB23_CellularStack(ATHandler &atHandler, int cid, nsapi_ip_stack_t stack_type) : AT_CellularStack(atHandler, cid, stack_type)
-{
- _at.set_urc_handler("+NSONMI:", mbed::Callback<void()>(this, &SERCOMM_TPB23_CellularStack::urc_nsonmi));
-}
-
-SERCOMM_TPB23_CellularStack::~SERCOMM_TPB23_CellularStack()
-{
-}
-
-nsapi_error_t SERCOMM_TPB23_CellularStack::socket_listen(nsapi_socket_t handle, int backlog)
-{
- return NSAPI_ERROR_UNSUPPORTED;
-}
-
-nsapi_error_t SERCOMM_TPB23_CellularStack::socket_accept(void *server, void **socket, SocketAddress *addr)
-{
- return NSAPI_ERROR_UNSUPPORTED;
-}
-
-nsapi_error_t SERCOMM_TPB23_CellularStack::socket_connect(nsapi_socket_t handle, const SocketAddress &address)
-{
- CellularSocket *socket = (CellularSocket *)handle;
-
- _at.lock();
- if (!socket->created) {
- const nsapi_error_t error_create = create_socket_impl(socket);
- if (error_create != NSAPI_ERROR_OK) {
- return error_create;
- }
- }
-
- _at.cmd_start("AT+NSOCO=");
- _at.write_int(socket->id);
- _at.write_string(address.get_ip_address(), false);
- _at.write_int(address.get_port());
- _at.cmd_stop();
- _at.resp_start();
- _at.resp_stop();
- _at.unlock();
-
- if (_at.get_last_error() == NSAPI_ERROR_OK) {
- socket->remoteAddress = address;
- socket->connected = true;
- return NSAPI_ERROR_OK;
- }
-
- return NSAPI_ERROR_NO_CONNECTION;
-}
-
-void SERCOMM_TPB23_CellularStack::urc_nsonmi()
-{
- int sock_id = _at.read_int();
-
- for (int i = 0; i < get_max_socket_count(); i++) {
- CellularSocket *sock = _socket[i];
- if (sock && sock->id == sock_id) {
- if (sock->_cb) {
- sock->_cb(sock->_data);
- }
- break;
- }
- }
-}
-
-int SERCOMM_TPB23_CellularStack::get_max_socket_count()
-{
- return TPB23_SOCKET_MAX;
-}
-
-bool SERCOMM_TPB23_CellularStack::is_protocol_supported(nsapi_protocol_t protocol)
-{
- return (protocol == NSAPI_UDP || protocol == NSAPI_TCP);
-}
-
-nsapi_error_t SERCOMM_TPB23_CellularStack::socket_close_impl(int sock_id)
-{
- _at.cmd_start("AT+NSOCL=");
- _at.write_int(sock_id);
- _at.cmd_stop_read_resp();
-
- tr_info("Close socket: %d error: %d", sock_id, _at.get_last_error());
-
- return _at.get_last_error();
-}
-
-nsapi_error_t SERCOMM_TPB23_CellularStack::create_socket_impl(CellularSocket *socket)
-{
- int sock_id = -1;
- bool socketOpenWorking = false;
-
- if (socket->proto == NSAPI_UDP) {
- _at.cmd_start("AT+NSOCR=DGRAM,17,");
- } else if (socket->proto == NSAPI_TCP) {
- _at.cmd_start("AT+NSOCR=STREAM,6,");
- } else {
- return NSAPI_ERROR_PARAMETER;
- }
- _at.write_int(socket->localAddress.get_port());
- _at.write_int(1);
- _at.cmd_stop();
- _at.resp_start();
- sock_id = _at.read_int();
- _at.resp_stop();
-
- socketOpenWorking = (_at.get_last_error() == NSAPI_ERROR_OK);
-
- if (!socketOpenWorking) {
- _at.cmd_start("AT+NSOCL=0");
- _at.cmd_stop_read_resp();
-
- if (socket->proto == NSAPI_UDP) {
- _at.cmd_start("AT+NSOCR=DGRAM,17,");
- } else if (socket->proto == NSAPI_TCP) {
- _at.cmd_start("AT+NSOCR=STREAM,6,");
- }
- _at.write_int(socket->localAddress.get_port());
- _at.write_int(1);
- _at.cmd_stop();
- _at.resp_start();
- sock_id = _at.read_int();
- _at.resp_stop();
-
- socketOpenWorking = (_at.get_last_error() == NSAPI_ERROR_OK);
- }
-
- if (!socketOpenWorking || (sock_id == -1)) {
- tr_error("Socket create failed!");
- return NSAPI_ERROR_NO_SOCKET;
- }
-
- // Check for duplicate socket id delivered by modem
- for (int i = 0; i < TPB23_SOCKET_MAX; i++) {
- CellularSocket *sock = _socket[i];
- if (sock && sock->created && sock->id == sock_id) {
- tr_error("Duplicate socket index: %d created:%d, sock_id: %d", i, sock->created, sock_id);
- return NSAPI_ERROR_NO_SOCKET;
- }
- }
-
- tr_info("Socket create id: %d", sock_id);
-
- socket->id = sock_id;
- socket->created = true;
-
- return NSAPI_ERROR_OK;
-}
-
-nsapi_size_or_error_t SERCOMM_TPB23_CellularStack::socket_sendto_impl(CellularSocket *socket, const SocketAddress &address,
- const void *data, nsapi_size_t size)
-{
- int sent_len = 0;
-
- if (size > PACKET_SIZE_MAX) {
- return NSAPI_ERROR_PARAMETER;
- }
-
- char *hexstr = new char[size * 2 + 1];
- int hexlen = char_str_to_hex_str((const char *)data, size, hexstr);
- // NULL terminated for write_string
- hexstr[hexlen] = 0;
-
- if (socket->proto == NSAPI_UDP) {
- _at.cmd_start("AT+NSOST=");
- _at.write_int(socket->id);
- _at.write_string(address.get_ip_address(), false);
- _at.write_int(address.get_port());
- _at.write_int(size);
- } else if (socket->proto == NSAPI_TCP) {
- _at.cmd_start("AT+NSOSD=");
- _at.write_int(socket->id);
- _at.write_int(size);
- } else {
- delete [] hexstr;
- return NSAPI_ERROR_PARAMETER;
- }
-
- _at.write_string(hexstr, false);
- _at.cmd_stop();
- _at.resp_start();
- // skip socket id
- _at.skip_param();
- sent_len = _at.read_int();
- _at.resp_stop();
-
- delete [] hexstr;
-
- if (_at.get_last_error() == NSAPI_ERROR_OK) {
- return sent_len;
- }
-
- return _at.get_last_error();
-}
-
-nsapi_size_or_error_t SERCOMM_TPB23_CellularStack::socket_recvfrom_impl(CellularSocket *socket, SocketAddress *address,
- void *buffer, nsapi_size_t size)
-{
- nsapi_size_or_error_t recv_len = 0;
- int port;
- char ip_address[NSAPI_IP_SIZE];
-
- _at.cmd_start("AT+NSORF=");
- _at.write_int(socket->id);
- _at.write_int(size <= PACKET_SIZE_MAX ? size : PACKET_SIZE_MAX);
- _at.cmd_stop();
- _at.resp_start();
- // receiving socket id
- _at.skip_param();
- _at.read_string(ip_address, sizeof(ip_address));
- port = _at.read_int();
- recv_len = _at.read_int();
- int hexlen = _at.read_hex_string((char *)buffer, size);
- // remaining length
- _at.skip_param();
- _at.resp_stop();
-
- if (!recv_len || (recv_len == -1) || (_at.get_last_error() != NSAPI_ERROR_OK)) {
- return NSAPI_ERROR_WOULD_BLOCK;
- }
-
- if (address) {
- address->set_ip_address(ip_address);
- address->set_port(port);
- }
-
- if (recv_len != hexlen) {
- tr_error("Not received as much data as expected. Should receive: %d bytes, received: %d bytes", recv_len, hexlen);
- }
- return recv_len;
-}
Daniel Lee