Specific Pelion ready example using features of Seeed Wio boards including cellular and SD Card

Dependencies:   WS2812 PixelArray

Fork of simple-mbed-cloud-example-wio_3g by Toyomasa Watarai

This example is known to work great on the following platforms:
Seeed Wio 3G and Seeed Wio LTE-M1/NB1(BG96) over cellular and using SD card.


Follow the Quick-Start instructions: https://cloud.mbed.com/quick-start

Example functionality

This example showcases the following device functionality:

  • Allow the user to change the state of the board LED from Pelion LWM2M led_state resource and PUT request.

Instructions to use this program with mbed CLI

1. Import the application into your desktop:

mbed import https://os.mbed.com/teams/Seeed/code/pelion-example-common/

cd pelion-example-common

2. Install the CLOUD_SDK_API_KEY


For instructions on how to generate your API key, please see the documentation.

3. Initialize firmware credentials (done once per repository). You can use the following command:

mbed dm init -d "<your company name in Pelion DM>" --model-name "<product model identifier>" -q --force

If above command do not work for your Mbed CLI, please consider upgrading Mbed CLI to version 1.9.x or above.

  • Set APN name, username and password in the mbed_app.json.

            "nsapi.default-cellular-plmn"      : "\"00000\"",
            "nsapi.default-cellular-sim-pin"   : "\"0000\"",
            "nsapi.default-cellular-apn"       : "\"apn\"",
            "nsapi.default-cellular-username"  : "\"username\"",
            "nsapi.default-cellular-password"  : "\"password\""


For the Wio LTE-M1/NB1(BG96) target, PLMN (Public land mobile network) should be specified to get quick connection to the network. This is usually found first 5 digit from your SIM card IMSI (International Mobile Subscriber Identity) number. e.g. 44052

4. Compile and program:

mbed compile -t <toolchain> -m WIO_3G

(supported toolchains : GCC_ARM / ARM / IAR)


  • Make sure the fields nsapi.default-cellular-sim-pin, nsapi.default-cellular-apn, nsapi.default-cellular-username and nsapi.default-cellular-password from the mbed_app.json file are filled in correctly. The correct values should appear in the user manual in the details of the SIM card.
  • Enable trace flag to have access to debug information "mbed-trace.enable": true.
  • Try both TCP and UDP socket types.
  • Try both "lwip.ppp-enabled": true and "lwip.ppp-enabled": false.
  • The modem and network may only support IPv6 in which case "lwip.ipv6-enabled": true shall be defined.
  • The SIM and modem must have compatible cellular technology (3G, 4G, NB-IoT, ...) supported and cellular network available.


8 months ago

File content as of revision 3:6f3b402196cc:

// ----------------------------------------------------------------------------
// Copyright 2016-2018 ARM Ltd.
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
// ----------------------------------------------------------------------------

#include "mbed.h"
#include "simple-mbed-cloud-client.h"
#include "FATFileSystem.h"
#include "LittleFileSystem.h"

#include "string.h"

// Default network interface object. Don't forget to change the WiFi SSID/password in mbed_app.json if you're using WiFi.
NetworkInterface *net = NetworkInterface::get_default_instance();

// Default block device available on the target board
BlockDevice *bd = BlockDevice::get_default_instance();

// Use FATFileSystem for SD card type blockdevices
FATFileSystem fs("fs");
// Use LittleFileSystem for non-SD block devices to enable wear leveling and other functions
LittleFileSystem fs("fs");

#if USE_BUTTON == 1
InterruptIn button(BUTTON1);
#endif /* USE_BUTTON */

DigitalOut SD_POWER(PA_15, 1);
#include "Wio_LED.h"

// Declaring pointers for access to Pelion Device Management Client resources outside of main()
MbedCloudClientResource *button_res;
MbedCloudClientResource *led_res;
MbedCloudClientResource *post_res;

// An event queue is a very useful structure to debounce information between contexts (e.g. ISR and normal threads)
// This is great because things such as network operations are illegal in ISR, so updating a resource in a button's fall() function is not allowed
EventQueue eventQueue;

 * PUT handler - sets the value of the built-in LED
 * @param resource The resource that triggered the callback
 * @param newValue Updated value for the resource
void put_callback(MbedCloudClientResource *resource, m2m::String newValue) {
    printf("PUT received. New value: %s\n", newValue.c_str());
    if(atoi(newValue.c_str())) {
    } else {

 * POST handler - prints the content of the payload
 * @param resource The resource that triggered the callback
 * @param buffer If a body was passed to the POST function, this contains the data.
 *               Note that the buffer is deallocated after leaving this function, so copy it if you need it longer.
 * @param size Size of the body
void post_callback(MbedCloudClientResource *resource, const uint8_t *buffer, uint16_t size) {
    printf("POST received (length %u). Payload: ", size);
    for (size_t ix = 0; ix < size; ix++) {
        printf("%02x ", buffer[ix]);

 * Button handler
 * This function will be triggered either by a physical button press or by a ticker every 5 seconds (see below)
void button_press() {
    int v = button_res->get_value_int() + 1;
    printf("Button clicked %d times\n", v);

 * Notification callback handler
 * @param resource The resource that triggered the callback
 * @param status The delivery status of the notification
void button_callback(MbedCloudClientResource *resource, const NoticationDeliveryStatus status) {
    printf("Button notification, status %s (%d)\n", MbedCloudClientResource::delivery_status_to_string(status), status);

 * Registration callback handler
 * @param endpoint Information about the registered endpoint such as the name (so you can find it back in portal)
void registered(const ConnectorClientEndpointInfo *endpoint) {
    printf("Registered to Pelion Device Management. Endpoint Name: %s\n", endpoint->internal_endpoint_name.c_str());

int main(void) {
    printf("\nStarting Simple Pelion Device Management Client example\n");

    int storage_status = fs.mount(bd);
    if (storage_status != 0) {
        printf("Storage mounting failed.\n");

#if USE_BUTTON == 1
    // If the User button is pressed ons start, then format storage.
    bool btn_pressed = (button.read() == MBED_CONF_APP_BUTTON_PRESSED_STATE);
    if (btn_pressed) {
        printf("User button is pushed on start...\n");
    bool btn_pressed = false;
#endif /* USE_BUTTON */

    if (storage_status || btn_pressed) {
        printf("Formatting the storage...\n");
        int storage_status = StorageHelper::format(&fs, bd);
        if (storage_status != 0) {
            printf("ERROR: Failed to reformat the storage (%d).\n", storage_status);
    } else {
        printf("You can hold the user button during boot to format the storage and change the device identity.\n");

    // Connect to the Internet (DHCP is expected to be on)
    printf("Connecting to the network using the default network interface...\n");
    net = NetworkInterface::get_default_instance();

    nsapi_error_t net_status = NSAPI_ERROR_NO_CONNECTION;
    while ((net_status = net->connect()) != NSAPI_ERROR_OK) {
        printf("Unable to connect to network (%d). Retrying...\n", net_status);

    printf("Connected to the network successfully. IP address: %s\n", net->get_ip_address());

    printf("Initializing Pelion Device Management Client...\n");

    // SimpleMbedCloudClient handles registering over LwM2M to Pelion Device Management
    SimpleMbedCloudClient client(net, bd, &fs);
    int client_status = client.init();
    if (client_status != 0) {
        printf("Pelion Client initialization failed (%d)\n", client_status);
        return -1;

    // Creating resources, which can be written or read from the cloud
    button_res = client.create_resource("3200/0/5501", "button_count");

    led_res = client.create_resource("3201/0/5853", "led_state");
    led_res->methods(M2MMethod::GET | M2MMethod::PUT);

    post_res = client.create_resource("3300/0/5605", "execute_function");

    printf("Initialized Pelion Device Management Client. Registering...\n");

    // Callback that fires when registering is complete

    // Register with Pelion DM

#if USE_BUTTON == 1
    // The button fires on an interrupt context, but debounces it to the eventqueue, so it's safe to do network operations
    printf("Press the user button to increment the LwM2M resource value...\n");
    // The timer fires on an interrupt context, but debounces it to the eventqueue, so it's safe to do network operations
    Ticker timer;
    timer.attach(eventQueue.event(&button_press), 5.0);
    printf("Simulating button press every 5 seconds...\n");
#endif /* USE_BUTTON */

    // You can easily run the eventQueue in a separate thread if required

#endif /* MBED_TEST_MODE */