78 lines
1.9 KiB
Arduino
78 lines
1.9 KiB
Arduino
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/*
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Basic MQTT example
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This sketch demonstrates the basic capabilities of the library.
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It connects to an MQTT server then:
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- publishes "hello world" to the topic "outTopic"
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- subscribes to the topic "inTopic", printing out any messages
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it receives. NB - it assumes the received payloads are strings not binary
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It will reconnect to the server if the connection is lost using a blocking
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reconnect function. See the 'mqtt_reconnect_nonblocking' example for how to
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achieve the same result without blocking the main loop.
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*/
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#include <SPI.h>
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#include <Ethernet.h>
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#include <PubSubClient.h>
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// Update these with values suitable for your network.
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byte mac[] = { 0xDE, 0xED, 0xBA, 0xFE, 0xFE, 0xED };
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IPAddress ip(172, 16, 0, 100);
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IPAddress server(172, 16, 0, 2);
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void callback(char* topic, byte* payload, unsigned int length) {
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Serial.print("Message arrived [");
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Serial.print(topic);
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Serial.print("] ");
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for (int i=0;i<length;i++) {
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Serial.print((char)payload[i]);
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}
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Serial.println();
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}
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EthernetClient ethClient;
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PubSubClient client(ethClient);
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void reconnect() {
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// Loop until we're reconnected
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while (!client.connected()) {
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Serial.print("Attempting MQTT connection...");
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// Attempt to connect
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if (client.connect("arduinoClient")) {
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Serial.println("connected");
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// Once connected, publish an announcement...
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client.publish("outTopic","hello world");
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// ... and resubscribe
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client.subscribe("inTopic");
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} else {
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Serial.print("failed, rc=");
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Serial.print(client.state());
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Serial.println(" try again in 5 seconds");
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// Wait 5 seconds before retrying
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delay(5000);
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}
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}
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}
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void setup()
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{
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Serial.begin(57600);
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client.setServer(server, 1883);
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client.setCallback(callback);
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Ethernet.begin(mac, ip);
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// Allow the hardware to sort itself out
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delay(1500);
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}
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void loop()
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{
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if (!client.connected()) {
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reconnect();
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}
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client.loop();
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}
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