Add WiFi101 AWS IoT example

Author: sandeepmistry

examples/WiFi101_AWS_IoT/WiFi101_AWS_IoT.ino

@@ -0,0 +1,95 @@
+// This example uses an Arduino/Genuino Zero together with
+// a WiFi101 Shield or a MKR1000 to connect to shiftr.io.
+//
+// IMPORTANT: This example uses the new WiFi101 library.
+//
+// IMPORTANT: You need to install/update the SSL certificates first:
+// https://github.com/arduino-libraries/WiFi101-FirmwareUpdater#to-update-ssl-certificates
+//
+// You can check on your device after a successful
+// connection here: https://shiftr.io/try.
+//
+// by Gilberto Conti
+// https://github.com/256dpi/arduino-mqtt
+
+#include <WiFi101.h>
+#include <MQTTClient.h>
+#include <ArduinoBearSSL.h>
+
+const char ssid[] = "ssid";
+const char pass[] = "pass";
+
+const char server[] = "xxxxxxxxxxxxxx.iot.xx-xxxx-x.amazonaws.com";
+
+// Get the cert data by:
+// 1) Creating a CSR using the ArduinoBearSSL -> Tools -> ECC508CSR example for key slot 0
+// 2) Creating a new thing and uploading the CSR for it
+// 3) Downloading the public key for the thing in AWS IoT
+// 4) Convert the base64 encoded cert to binary
+const byte cert[] = {
+  // ...
+};
+
+WiFiClient wifiClient;
+BearSSLClient net(wifiClient, 0, cert, sizeof(cert));
+MQTTClient client;
+
+unsigned long lastMillis = 0;
+
+unsigned long getTime() {
+  return WiFi.getTime();
+}
+
+void setup() {
+  Serial.begin(115200);
+
+  ArduinoBearSSL.onGetTime(getTime);
+  
+  WiFi.begin(ssid, pass);
+
+  // Note: Local domain names (e.g. "Computer.local" on OSX) are not supported by Arduino.
+  // You need to set the IP address directly.
+  //
+  // MQTT brokers usually use port 8883 for secure connections.
+  client.begin(server, 8883, net);
+  client.onMessage(messageReceived);
+
+  connect();
+}
+
+void connect() {
+  Serial.print("checking wifi...");
+  while (WiFi.status() != WL_CONNECTED) {
+    Serial.print(".");
+    delay(1000);
+  }
+
+  Serial.print("\nconnecting...");
+  while (!client.connect("arduino")) {
+    Serial.print(".");
+    delay(1000);
+  }
+
+  Serial.println("\nconnected!");
+
+  client.subscribe("/hello");
+  // client.unsubscribe("/hello");
+}
+
+void loop() {
+  client.loop();
+
+  if (!client.connected()) {
+    connect();
+  }
+
+  // publish a message roughly every second.
+  if (millis() - lastMillis > 1000) {
+    lastMillis = millis();
+    client.publish("/hello", "world");
+  }
+}
+
+void messageReceived(String &topic, String &payload) {
+  Serial.println("incoming: " + topic + " - " + payload);
+}