Servizi AWS IoT core e MQTT: connettere i dispositivi Arduino SAMD (WiFiNINA) – 5

    {
      "Effect": "Allow",
      "Action": "iot:Connect",
      "Resource": "arn:aws:iot:[Region]:[Account ID]:client/arduinoSAMD_relay"
    },

alexa-skill-manage-relay/arduinoSAMD_relay_iot_core/sketch/aws_iot_core_arduino_SAMD

aws_certificate.h
aws_parameter.h
wifi_credential.h
aws_iot_core_arduinoSAMD.ino

char WIFI_SSID[] = "<YOUR-SSID>";
char WIFI_PASSWORD[] = "<YOUR-PASSWD>";

#define THINGNAME "esp32_relay"
char AWS_IOT_ENDPOINT[] = "XXXXXXXXXXXXXX-ats.iot.eu-west-1.amazonaws.com";

#define AWS_IOT_PUBLISH_TOPIC   "relay/pub"
#define AWS_IOT_SUBSCRIBE_TOPIC "relay/sub"

#include <avr/pgmspace.h>

// Device Certificate (XXXXXXXXXX-certificate.pem.crt)
// Fill in the boards public certificate
const char AWS_CERT_CRT[] = R"(
-----BEGIN CERTIFICATE-----
[...]
-----END CERTIFICATE-----
)";

#include <WiFiNINA.h> // change to #include <WiFi101.h> for MKR1000
#include <ArduinoECCX08.h>
#include <ArduinoBearSSL.h>

/*
 *   Amazon AWS IoT core connection from Arduino SAMD boards
 *
 *   This sketch securely connects to an AWS IoT using MQTT over WiFi.
 *   It uses a private key stored in the ATECC508A and a public
 *   certificate for SSL/TLS authetication.
 *
 *   It publishes a message every 5 seconds to arduino/pub
 *   topic and subscribes to messages on the arduino/sub
 *   topic.
 *
 *  by Mischianti Renzo <https://mischianti.org>
 *
 *  https://mischianti.org
 *
 */
#include "Arduino.h"
#include "aws_certificate.h"
#include "aws_parameter.h"
#include "wifi_credential.h"

#include <WiFiNINA.h> // change to #include <WiFi101.h> for MKR1000
#include <ArduinoECCX08.h>
#include <ArduinoBearSSL.h>

#include <MQTTClient.h>
#include <ArduinoJson.h>

// Secure connection
WiFiClient    wifiClient;            // Used for the TCP socket connection
BearSSLClient client(wifiClient); // Used for SSL/TLS connection, integrates with ECC508
// Client MQTT
MQTTClient clientMQTT = MQTTClient(256);

// Callback for every message on the topic subscribed
void messageCallback(String &topic, String &payload);
// Establish connection to MQTT
bool manageAWSConnection();
// Subscribe topic
bool manageAWSSubscription();
// Publish message to topic
bool publishMessage();

unsigned long getTime() {
  // get the current time from the WiFi module
  return WiFi.getTime();
}

void setup()
{
	Serial.begin(115200);
	while(!Serial){}
	Serial.flush();
	Serial.println();

	  if (!ECCX08.begin()) {
		Serial.println("No ECCX08 present!");
		while (1);
	  }

	  // Set a callback to get the current time
	  // used to validate the servers certificate
	  ArduinoBearSSL.onGetTime(getTime);

	  // Set the ECCX08 slot to use for the private key
	  // and the accompanying public certificate for it
	  client.setEccSlot(0, (const char*)AWS_CERT_CRT);

	// WIFI_SSID, WIFI_PASSWORD Stored on wifi_credential.h file
	WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

	Serial.print("Connecting to ");
	Serial.print(WIFI_SSID); Serial.println("");

	int i = 0;
	while (WiFi.status() != WL_CONNECTED) { // Wait for the Wi-Fi to connect
		delay(1000);
		Serial.print(++i); Serial.print('.');
	}

	Serial.println('\n');
	Serial.println("Connection established!");
	Serial.print("IP address:\t");
	Serial.println(WiFi.localIP());         // Send the IP address of the ESP8266 to the computer

	if (manageAWSConnection()){
		manageAWSSubscription();
	}
}

unsigned long lastSendingTime = millis();
unsigned long sendMessageEveryMillis = 5000;

void loop()
{
	clientMQTT.loop();
	if (lastSendingTime+sendMessageEveryMillis<millis()){
		publishMessage();
		lastSendingTime = millis();
	}
}

bool manageAWSConnection(){
	// Connect to the MQTT broker on the AWS endpoint
	clientMQTT.begin(AWS_IOT_ENDPOINT, 8883, client);

	// Create a message handler
	clientMQTT.onMessage(messageCallback);

	Serial.print("Connecting to AWS IOT");

	while (!clientMQTT.connect(THINGNAME)) {
		Serial.print(".");
		delay(100);
	}

	if(!clientMQTT.connected()){
		Serial.println("AWS IoT Timeout!");
		return false;
	}
	return true;
}

bool manageAWSSubscription(){
	  // Subscribe to a topic
	  if (clientMQTT.subscribe(AWS_IOT_SUBSCRIBE_TOPIC)){
		  Serial.println("AWS IoT Connected!");
		  return true;
	  }else{
		  Serial.print("AWS IoT ERROR: ");
		  Serial.println(clientMQTT.lastError());
		  return false;
	  }
}

void messageCallback(String &topic, String &payload) {
	Serial.println("incoming: [" + topic + "]" );
	Serial.println("---------------------------" );

	StaticJsonDocument<200> doc;
	deserializeJson(doc, payload);
	serializeJsonPretty(doc, Serial);
	Serial.println();
	Serial.println("---------------------------" );
}

bool publishMessage()
{
	// Create simple message
	DynamicJsonDocument doc(512);

	doc["time"] = millis();
	doc["deviceName"] = "Arduino SAMD";
	doc["status"] = "OK";

	char jsonBuffer[512];
	serializeJson(doc, jsonBuffer); // print to client

	Serial.print("Message on ");
	Serial.print(AWS_IOT_PUBLISH_TOPIC);
	Serial.print(" topic... ");
	// Publish message to AWS_IOT_PUBLISH_TOPIC
	if (clientMQTT.publish(AWS_IOT_PUBLISH_TOPIC, jsonBuffer)){
		Serial.println("Published!");
		return true;
	}else{
		Serial.println("Error!");
		return false;
	}
}

/*
 *   Amazon AWS IoT core connection from Arduino SAMD boards
 *
 *   This sketch securely connects to an AWS IoT using MQTT over WiFi.
 *   It uses a private key stored in the ATECC508A and a public
 *   certificate for SSL/TLS authetication.
 *   With ArduinoMqttClient library.
 *
 *   It publishes a message every 5 seconds to arduino/pub
 *   topic and subscribes to messages on the arduino/sub
 *   topic.
 *
 *  by Mischianti Renzo <https://mischianti.org>
 *
 *  https://mischianti.org
 *
 */

#include "aws_certificate.h"
#include "aws_parameter.h"
#include "wifi_credential.h"

#include <ArduinoBearSSL.h>
#include <ArduinoECCX08.h>
#include <ArduinoMqttClient.h>
#include <WiFiNINA.h> // change to #include <WiFi101.h> for MKR1000
#include <ArduinoJson.h>

/////// Enter your sensitive data in arduino_secrets.h

WiFiClient    wifiClient;            // Used for the TCP socket connection
BearSSLClient sslClient(wifiClient); // Used for SSL/TLS connection, integrates with ECC508
MqttClient    mqttClient(sslClient);

unsigned long lastMillis = 0;

unsigned long getTime();
void onMessageReceived(int messageSize);
void connectWiFi();
void connectMQTT();
bool publishMessage();

void setup() {
  Serial.begin(115200);
  while (!Serial);

  if (!ECCX08.begin()) {
    Serial.println("No ECCX08 present!");
    while (1);
  }

  // Set a callback to get the current time
  // used to validate the servers certificate
  ArduinoBearSSL.onGetTime(getTime);

  // Set the ECCX08 slot to use for the private key
  // and the accompanying public certificate for it
  sslClient.setEccSlot(0, AWS_CERT_CRT);

  // Optional, set the client id used for MQTT,
  // each device that is connected to the broker
  // must have a unique client id. The MQTTClient will generate
  // a client id for you based on the millis() value if not set
  //
  mqttClient.setId(THINGNAME);

  // Set the message callback, this function is
  // called when the MQTTClient receives a message
  mqttClient.onMessage(onMessageReceived);
}

void loop() {
  if (WiFi.status() != WL_CONNECTED) {
    connectWiFi();
  }

  if (!mqttClient.connected()) {
    // MQTT client is disconnected, connect
    connectMQTT();
  }

  // poll for new MQTT messages and send keep alives
  mqttClient.poll();

  // publish a message roughly every 5 seconds.
  if (millis() - lastMillis > 5000) {
    lastMillis = millis();

    publishMessage();
  }
}

unsigned long getTime() {
  // get the current time from the WiFi module  
  return WiFi.getTime();
}

void connectWiFi() {
  Serial.print("Attempting to connect to SSID: ");
  Serial.print(WIFI_SSID);
  Serial.print(" ");

  while (WiFi.begin(WIFI_SSID, WIFI_PASSWORD) != WL_CONNECTED) {
    // failed, retry
    Serial.print(".");
    delay(5000);
  }
  Serial.println();

  Serial.println("You're connected to the network");
  Serial.println();
}

void connectMQTT() {
  Serial.print("Attempting to MQTT broker: ");
  Serial.print(AWS_IOT_ENDPOINT);
  Serial.println(" ");

  while (!mqttClient.connect(AWS_IOT_ENDPOINT, 8883)) {
    // failed, retry
    Serial.print(".");
    delay(5000);
  }
  Serial.println();

  Serial.println("You're connected to the MQTT broker");
  Serial.println();

  // subscribe to a topic
  mqttClient.subscribe(AWS_IOT_SUBSCRIBE_TOPIC);
}

bool publishMessage()
{
	// Create simple message
	DynamicJsonDocument doc(512);

	doc["time"] = millis();
	doc["deviceName"] = "Arduino SAMD";
	doc["status"] = "OK";

	char jsonBuffer[512];
	size_t buffSize = serializeJson(doc, jsonBuffer); // print to client

	Serial.print("Message on ");
	Serial.print(AWS_IOT_PUBLISH_TOPIC);
	Serial.print(" topic... ");
	// Publish message to AWS_IOT_PUBLISH_TOPIC
	mqttClient.beginMessage(AWS_IOT_PUBLISH_TOPIC,(unsigned long)buffSize);
	mqttClient.print(jsonBuffer);
	if(mqttClient.endMessage() == 1){
		Serial.println("Published!");
		return true;
	}else{
		Serial.println("Error!");
		return false;
	}
}


void onMessageReceived(int messageSize) {
	Serial.println("incoming: [" + mqttClient.messageTopic() + "]" );
	Serial.println("---------------------------" );

	StaticJsonDocument<200> doc;
	deserializeJson(doc, mqttClient);
	serializeJsonPretty(doc, Serial);
	Serial.println();
	Serial.println("---------------------------" );
}