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#include <PubSubClient.h>
#include <ESP8266WiFi.h>
const char* ssid = ".................";
const char* password = "................";
char* topic = "esp8266_arduino_out";
char* server = "iot.eclipse.org";
WiFiClient wifiClient;
PubSubClient client(server, 1883, callback, wifiClient);
void callback(char* topic, byte* payload, unsigned int length) {
// handle message arrived
}
String macToStr(const uint8_t* mac)
{
String result;
for (int i = 0; i < 6; ++i) {
result += String(mac[i], 16);
if (i < 5)
result += ':';
}
return result;
}
void setup() {
Serial.begin(115200);
delay(10);
Serial.println();
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
// Generate client name based on MAC address and last 8 bits of microsecond counter
String clientName;
clientName += "esp8266-";
uint8_t mac[6];
WiFi.macAddress(mac);
clientName += macToStr(mac);
clientName += "-";
clientName += String(micros() & 0xff, 16);
Serial.print("Connecting to ");
Serial.print(server);
Serial.print(" as ");
Serial.println(clientName);
if (client.connect((char*) clientName.c_str())) {
Serial.println("Connected to MQTT broker");
Serial.print("Topic is: ");
Serial.println(topic);
if (client.publish(topic, "hello from ESP8266")) {
Serial.println("Publish ok");
}
else {
Serial.println("Publish failed");
}
}
else {
Serial.println("MQTT connect failed");
Serial.println("Will reset and try again...");
abort();
}
}
void loop() {
static int counter = 0;
String payload = "{\"micros\":";
payload += micros();
payload += ",\"counter\":";
payload += counter;
payload += "}";
if (client.connected()){
Serial.print("Sending payload: ");
Serial.println(payload);
if (client.publish(topic, (char*) payload.c_str())) {
Serial.println("Publish ok");
}
else {
Serial.println("Publish failed");
}
}
++counter;
delay(5000);
}
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