Added sender with reconnect example

examples/WiFiSimpleSender/WiFiSimpleSender.ino

@@ -77,17 +77,17 @@ void setup() {
 }
 
 void loop() {
-  // call poll() regularly to allow the library to send MQTT keep alives which
-  // avoids being disconnected by the broker
-  mqttClient.poll();
-
   // avoid having delays in loop, we'll use the strategy from BlinkWithoutDelay
   // see: File -> Examples -> 02.Digital -> BlinkWithoutDelay for more info
   unsigned long currentMillis = millis();
 
   if (currentMillis - previousMillis >= interval) {
     // save the last time a message was sent
     previousMillis = currentMillis;
+
+    // call poll() regularly to allow the library to send MQTT keep alives which
+    // avoids being disconnected by the broker
+    mqttClient.poll();
 
     Serial.print("Sending message to topic: ");
     Serial.println(topic);

examples/WiFiSimpleSenderReconnect/WiFiSimpleSenderReconnect.ino

@@ -0,0 +1,137 @@
+/*
+  ArduinoMqttClient - WiFi Reconnect
+
+  This example connects to a MQTT broker and publishes a message to
+  a topic once a second. If the client is disconnected from the broker,
+  it automatically tries to reconnect. 
+
+
+  The circuit:
+  - Arduino MKR 1000, MKR 1010 or Uno WiFi Rev.2 board
+
+
+  This example code is in the public domain.
+*/
+
+#include <ArduinoMqttClient.h>
+#include <WiFiNINA.h> // for MKR1000 change to: #include <WiFi101.h>
+
+#include "arduino_secrets.h"
+///////please enter your sensitive data in the Secret tab/arduino_secrets.h
+char ssid[] = SECRET_SSID;        // your network SSID (name)
+char pass[] = SECRET_PASS;    // your network password (use for WPA, or use as key for WEP)
+
+// To connect with SSL/TLS:
+// 1) Change WiFiClient to WiFiSSLClient.
+// 2) Change port value from 1883 to 8883.
+// 3) Change broker value to a server with a known SSL/TLS root certificate 
+//    flashed in the WiFi module.
+
+WiFiClient wifiClient;
+MqttClient mqttClient(wifiClient);
+
+const char broker[] = "test.mosquitto.org";
+int        port     = 1883;
+const char topic[]  = "arduino/simple";
+
+const long interval = 1000;
+unsigned long previousMillis = 0;
+
+int count = 0;
+
+int attemptReconnect(){
+  if (!mqttClient.connect(broker, port)) {
+    Serial.print("MQTT connection failed! Error code = ");
+    Serial.println(mqttClient.connectError());
+
+  }
+  return mqttClient.connectError(); // return status
+}
+
+void setup() {
+  //Initialize serial and wait for port to open:
+  Serial.begin(9600);
+
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  // attempt to connect to Wifi network:
+  Serial.print("Attempting to connect to WPA SSID: ");
+  Serial.println(ssid);
+
+  while (WiFi.begin(ssid, pass) != WL_CONNECTED) {
+    // failed, retry
+    Serial.print(".");
+
+    delay(5000);
+  }
+
+
+  Serial.println("You're connected to the network");
+  Serial.println();
+
+
+  // You can provide a unique client ID, if not set the library uses Arduino-millis()
+  // Each client must have a unique client ID
+  // mqttClient.setId("14");
+
+  // You can provide a username and password for authentication
+  // mqttClient.setUsernamePassword(SECRET_MQTT_USER, SECRET_MQTT_PW);
+
+
+  Serial.print("Attempting to connect to the MQTT broker: ");
+  Serial.println(broker);
+
+
+  if (!mqttClient.connect(broker, port)) {
+    Serial.print("MQTT connection failed! Error code = ");
+    Serial.println(mqttClient.connectError());
+
+    while (1);
+  }
+
+
+  Serial.println("You're connected to the MQTT broker!");
+  Serial.println();
+
+}
+
+void loop() {
+  // avoid having delays in loop, we'll use the strategy from BlinkWithoutDelay
+  // see: File -> Examples -> 02.Digital -> BlinkWithoutDelay for more info
+  unsigned long currentMillis = millis();
+
+  if (currentMillis - previousMillis >= interval) {
+    previousMillis = currentMillis;
+
+    mqttClient.poll(); // poll to avoid beeing disconnected
+
+
+    Serial.print("Sending message to topic: ");
+    Serial.println(topic);
+    Serial.print("hello ");
+    Serial.println(count);
+
+    // send message, the Print interface can be used to set the message contents
+    mqttClient.beginMessage(topic);
+    mqttClient.print("hello ");
+    mqttClient.print(count);
+    mqttClient.endMessage();
+
+    Serial.println();
+
+    count++;
+
+    if(!mqttClient.connected()){ // if the client has been disconnected, 
+      Serial.println("Client disconnected, attempting reconnection");
+      Serial.println();
+
+      if(!attemptReconnect()){ // try reconnecting
+        Serial.print("Client reconnected!");
+        Serial.println();
+
+      }
+    }
+  }
+}

examples/WiFiSimpleSenderReconnect/arduino_secrets.h

@@ -0,0 +1,4 @@
+#define SECRET_SSID ""
+#define SECRET_PASS ""
+#define SECRET_MQTT_USER ""
+#define SECRET_MQTT_PW ""

examples/WiFiSimpleSenderReconnect/sketch.json

@@ -0,0 +1 @@
+{"cpu":{"name":"Arduino MKR WiFi 1010","com_name":"COM23","fqbn":"arduino:samd:mkrwifi1010","flavour":"default"},"secrets":[{"name":"SECRET_SSID","value":"","isOptional":false},{"name":"SECRET_PASS","value":"","isOptional":false},{"name":"SECRET_MQTT_USER","value":"","isOptional":true},{"name":"SECRET_MQTT_PW","value":"","isOptional":true}]}