esmp3/lib/pubsubclient/examples/mqtt_reconnect_nonblocking/mqtt_reconnect_nonblocking.ino

68 lines
1.4 KiB
C++

/*
Reconnecting MQTT example - non-blocking
This sketch demonstrates how to keep the client connected
using a non-blocking reconnect function. If the client loses
its connection, it attempts to reconnect every 5 seconds
without blocking the main loop.
*/
#include <SPI.h>
#include <Ethernet.h>
#include <PubSubClient.h>
// Update these with values suitable for your hardware/network.
byte mac[] = { 0xDE, 0xED, 0xBA, 0xFE, 0xFE, 0xED };
IPAddress ip(172, 16, 0, 100);
IPAddress server(172, 16, 0, 2);
void callback(char* topic, byte* payload, unsigned int length) {
// handle message arrived
}
EthernetClient ethClient;
PubSubClient client(ethClient);
long lastReconnectAttempt = 0;
boolean reconnect() {
if (client.connect("arduinoClient")) {
// Once connected, publish an announcement...
client.publish("outTopic","hello world");
// ... and resubscribe
client.subscribe("inTopic");
}
return client.connected();
}
void setup()
{
client.setServer(server, 1883);
client.setCallback(callback);
Ethernet.begin(mac, ip);
delay(1500);
lastReconnectAttempt = 0;
}
void loop()
{
if (!client.connected()) {
long now = millis();
if (now - lastReconnectAttempt > 5000) {
lastReconnectAttempt = now;
// Attempt to reconnect
if (reconnect()) {
lastReconnectAttempt = 0;
}
}
} else {
// Client connected
client.loop();
}
}