Generic Pelion Device Management example for various ST-based boards.

This example is known to work great on the following platforms:

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

DISCO_L475E_IOT01A DISCO_F413H DISCO_F746NG NUCLEO_F429ZI, NUCLEO_F767ZI, NUCLEO_F746ZG,NUCLEO_F207ZG

Example functionality

This example showcases the following device functionality:

  • Read ADC temperature and ADC vref, and report them as Pelion LWM2M resources (see image below).
  • On user button click, increment Pelion LWM2M button resource.
  • Allow the user to change the state of the board LED from Pelion LWM2M led_state resource and PUT request.

/media/uploads/screamer/pelion_st_adc_reading.png

ST Nucleo 144 hardware setup

The ST Nucleo family of boards don't have storage onboard and therefore you will need an SD card. See the image below how to wire an SD card to any ST Nucleo 144 board.

/media/uploads/screamer/st_nucleo_144_sd.jpeg?v=4

If you are not a first-time Pelion Device Management user your device's SD card may already have connect and update certificates on it. If this is the case, remove and manually format your micro SD card, flash the binary to the device and then re-insert your micro SD card.

Use this example with Mbed CLI

1. Import the application into your desktop:

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

cd pelion-example-common

2. Install the CLOUD_SDK_API_KEY

mbed config -G CLOUD_SDK_API_KEY <PELION_DM_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 1.8.x or above.

4. Compile and program:

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

(supported toolchains : GCC_ARM / ARM / IAR)

main.cpp

Committer:
screamer
Date:
2 months ago
Revision:
18:a5a85e6482b9
Parent:
14:1ac188d5404d

File content as of revision 18:a5a85e6482b9:

// ----------------------------------------------------------------------------
// 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,
// 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.
// ----------------------------------------------------------------------------
#ifndef MBED_TEST_MODE

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

// 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;

// 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();

#if COMPONENT_SD || COMPONENT_NUSD
// Use FATFileSystem for SD card type blockdevices
FATFileSystem fs("fs", bd);
#else
// Use LittleFileSystem for non-SD block devices to enable wear leveling and other functions
LittleFileSystem fs("fs", bd);
#endif

// Default User button for GET example
InterruptIn button(BUTTON1);
// Default LED to use for PUT/POST example
DigitalOut led(LED1);
// Temperature reading from microcontroller
AnalogIn adc_temp(ADC_TEMP);
// Voltage reference reading from microcontroller
AnalogIn adc_vref(ADC_VREF);

#define SENSORS_POLL_INTERVAL 1.0

// Declaring pointers for access to Pelion Client resources outside of main()
MbedCloudClientResource *res_button;
MbedCloudClientResource *res_led;
MbedCloudClientResource *res_temperature;
MbedCloudClientResource *res_voltage;

// When the device is registered, this variable will be used to access various useful information, like device ID etc.
static const ConnectorClientEndpointInfo* endpointInfo;

/**
 * PUT handler
 * @param resource The resource that triggered the callback
 * @param newValue Updated value for the resource
 */
void led_put_callback(MbedCloudClientResource *resource, m2m::String newValue) {
    printf("PUT received. New value: %s\n", newValue.c_str());
    led = atoi(newValue.c_str());
}

/**
 * POST handler
 * @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 led_post_callback(MbedCloudClientResource *resource, const uint8_t *buffer, uint16_t size) {
    printf("POST received. Payload: %s\n", res_led->get_value().c_str());
    led = atoi(res_led->get_value().c_str());
}

/**
 * Button function triggered by the physical button press.
 */
void button_press() {
    int v = res_button->get_value_int() + 1;
    res_button->set_value(v);
    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());
    endpointInfo = endpoint;
}

/**
 * Update sensors and report their values.
 * This function is called periodically.
 */
void sensors_update() {
    float temp = adc_temp.read()*100;
    float vref = adc_vref.read();
    printf("ADC temp:  %6.4f C,  vref: %6.4f %%\r\n", temp, vref);
    if (endpointInfo) {
        res_temperature->set_value(temp);
        res_voltage->set_value(vref);
    }
}


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

    // If the User button is pressed ons start, then format storage.
    DigitalIn *user_button = new DigitalIn(BUTTON1);
#if TARGET_DISCO_L475VG_IOT01A
    // The user button on DISCO_L475VG_IOT01A works the other way around
    const int PRESSED = 0;
#else
    const int PRESSED = 1;
#endif
    if (user_button->read() == PRESSED) {
        printf("User button is pushed on start. Formatting the storage...\n");
        int storage_status = fs.reformat(bd);
        if (storage_status != 0) {
            if (bd->erase(0, bd->size()) == 0) {
                if (fs.format(bd) == 0) {
                    storage_status = 0;
                    printf("The storage reformatted successfully.\n");
                }
            }
        }
        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 = -1;
    for (int tries = 0; tries < 3; tries++) {
        net_status = net->connect();
        if (net_status == NSAPI_ERROR_OK) {
            break;
        } else {
            printf("Unable to connect to network. Retrying...\n");
        }
    }

    if (net_status != NSAPI_ERROR_OK) {
        printf("ERROR: Connecting to the network failed (%d)!\n", net_status);
        return -1;
    }

    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 DM
    SimpleMbedCloudClient client(net, bd, &fs);
    int client_status = client.init();
    if (client_status != 0) {
        printf("ERROR: Pelion Client initialization failed (%d)\n", client_status);
        return -1;
    }

    // Creating resources, which can be written or read from the cloud
    res_button = client.create_resource("3200/0/5501", "button_count");
    res_button->set_value(0);
    res_button->methods(M2MMethod::GET);
    res_button->observable(true);
    res_button->attach_notification_callback(button_callback);

    res_led = client.create_resource("3201/0/5853", "led_state");
    res_led->set_value(1);
    res_led->methods(M2MMethod::GET | M2MMethod::PUT);
    res_led->attach_put_callback(led_put_callback);

    // Sensor resources
    res_temperature = client.create_resource("3303/0/5700", "temperature");
    res_temperature->set_value(0);
    res_temperature->methods(M2MMethod::GET);
    res_temperature->observable(true);

    res_voltage = client.create_resource("3316/0/5700", "voltage");
    res_voltage->set_value(0);
    res_voltage->methods(M2MMethod::GET);
    res_voltage->observable(true);

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

    // Callback that fires when registering is complete
    client.on_registered(&registered);

    // Register with Pelion DM
    client.register_and_connect();

    int i = 600; // wait up 60 seconds before attaching sensors and button events
    while (i-- > 0 && !client.is_client_registered()) {
        wait_ms(100);
    }

    button.fall(eventQueue.event(&button_press));
    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(&sensors_update), SENSORS_POLL_INTERVAL);

    // You can easily run the eventQueue in a separate thread if required
    eventQueue.dispatch_forever();
}
#endif