How can I publish data from esp32 to emqx in Qos Level 1 or 2 ?
#include <Arduino.h>
#include <WiFi.h>
#include <PubSubClient.h>
// WiFi
const char *ssid = "XXXXXXXXXXXX";
const char *password = "YYYYYY";
IPAddress local_IP(192, 168, X, X);
IPAddress gateway(192, X, X, X);
IPAddress subnet(X, X, X, 0);
IPAddress primaryDNS(0, 0, 0, 0);
// MQTT Broker
const char *mqtt_broker = "XXXXXXXXX";
const char *topic = "esp32/test";
const char *mqtt_username = "emqx";
const char *mqtt_password = "public";
const int mqtt_port = 1883;
WiFiClient espClient;
PubSubClient client(espClient);
const int buttonUpPin = 15;
const int buttonDownPin = 2;
const int buttonClearPin = 0;
int count = 0;
void callback(char *topic, byte *payload, unsigned int length) {
Serial.print("Message arrived in topic: ");
Serial.println(topic);
Serial.print("Message:");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
Serial.println("-----------------------");
}
void publishCount(const char *topic, int c) {
Serial.print("Count: ");
Serial.println(c);
client.publish(topic, String(c).c_str(),MQTTpubQos);
}
void setup() {
Serial.begin(115200);
pinMode(buttonUpPin, INPUT_PULLUP);
pinMode(buttonDownPin, INPUT_PULLUP);
pinMode(buttonClearPin, INPUT_PULLUP);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.println("Connecting to WiFi..");
}
Serial.println("Connected to the WiFi network");
client.setServer(mqtt_broker, mqtt_port);
client.setCallback(callback);
while (!client.connected()) {
String client_id = "esp32-client-";
client_id += String(WiFi.macAddress());
Serial.printf("The client %s connects to the public mqtt broker\n", client_id.c_str());
if (client.connect(client_id.c_str(), mqtt_username, mqtt_password)) {
Serial.println("Public emqx mqtt broker connected");
} else {
Serial.print("failed with state ");
Serial.print(client.state());
delay(2000);
}
}
client.publish(topic,"Hi EMQX & Node-red ! I'm ESP32 ^^",MQTTpubQos);
client.subscribe(topic);
}
void loop() {
if (digitalRead(buttonUpPin) == LOW) {
count++;
publishCount(topic, count);
delay(200);
}
if (digitalRead(buttonDownPin) == LOW) {
count--;
publishCount(topic, count);
delay(200);
}
if (digitalRead(buttonClearPin) == LOW) {
count = 0;
publishCount(topic, count);
while (digitalRead(buttonClearPin) == LOW) {}
delay(200);
}
client.loop();
}
PS. i use PlatformIO to upload on ESP32