HiveMQ using ESP32 and NODERED

Hi here a small tutorial of how to connect the ESP32 with HIVEMQ and use NODE-RED as a dashboard / visualiser.

First here a template code (that work flawlessly for me):Just replace the XXXX with your input/value
make sure you install the needed library.

#include <WiFi.h>
#include <PubSubClient.h>
#include <WiFiClientSecure.h>

//---- WiFi settings
const char* ssid = “XXXX”;
const char* password = “XXXX”;
//---- MQTT Broker settings
const char* mqtt_server = “XXXX”; // replace with your broker url
const char* mqtt_username = “XXXX”;
const char* mqtt_password = “XXXX”;
const int mqtt_port =8883;

WiFiClientSecure espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;

#define MSG_BUFFER_SIZE (50)
char msg[MSG_BUFFER_SIZE];

const char* sensor1_topic= “sensor1”;
const char* sensor2_topic=“sensor2”;

static const char *root_ca PROGMEM = R"EOF(
-----BEGIN CERTIFICATE-----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=
-----END CERTIFICATE-----
)EOF";

void setup() {

Serial.begin(9600);
Serial.print("\nConnecting to ");
Serial.println(ssid);

WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(“.”);
}
randomSeed(micros());
Serial.println("\nWiFi connected\nIP address: ");
Serial.println(WiFi.localIP());

while (!Serial) delay(1);

espClient.setCACert(root_ca);
client.setServer(mqtt_server, mqtt_port);
client.setCallback(callback);
}

void loop() {

if (!client.connected()) reconnect();
client.loop();

publishMessage(sensor1_topic,String(XXXX),true);
publishMessage(sensor2_topic,String(XXXX),true);
}

//=======================================================================Function=================================================================================

void reconnect() {
// Loop until we’re reconnected
while (!client.connected()) {
Serial.print(“Attempting MQTT connection…”);
String clientId = “ESP8266Client-”; // Create a random client ID
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str(), mqtt_username, mqtt_password)) {
Serial.println(“connected”);

client.subscribe(command1_topic); // subscribe the topics here
//client.subscribe(command2_topic); // subscribe the topics here
} else {
Serial.print(“failed, rc=”);
Serial.print(client.state());
Serial.println(" try again in 5 seconds"); // Wait 5 seconds before retrying
delay(5000);
}
}
}

//=======================================
// This void is called every time we have a message from the broker

void callback(char* topic, byte* payload, unsigned int length) {
String incommingMessage = “”;
for (int i = 0; i < length; i++) incommingMessage+=(char)payload[i];
Serial.println(“Message arrived [”+String(topic)+“]”+incommingMessage);
// check for other commands
/* else if( strcmp(topic,command2_topic) == 0){
if (incommingMessage.equals(“1”)) { } // do something else
}
*/
}

//======================================= publising as string
void publishMessage(const char* topic, String payload , boolean retained){
if (client.publish(topic, payload.c_str(), true))
Serial.println(“Message publised [”+String(topic)+"]: "+payload);
}

2 Likes

Hi @Mike,

Thank you so much for being an active member of our community!
We certainly appreciate this a lot.

Cheers,
Florian from the HiveMQ Team.

1 Like

Once the ESP32 is connected to the BROKER you should see 1/100 in your cluster.

afterward you will have to setup credential in your HIVEMQ to do so go to ‘‘Your cluster → manage Cluster → acces management’’ in this section you can add your MQTT Credentials.

after the connection of the client confirmed head over NodeRed and add a MQTT IN flow

double clic on said flow and enter the name of your Topic

after that clic on the pencil on the right to the server

in the SERVER field paste your HIVEMQ URL
Check the USE TLS box
goto SECURITY section and enter your credential previously configured

Once this is done you should see a blue dot underneath the MQTT IN FLOW that confirm you are connected to the broker.

Only thing left is to creat your own dashboard

Hope this help, if you have any question il try to answer them as clearly as i can.

1 Like

Here a picture with a volume trend using Node-Red with HiveMQ

1 Like


Here is a picture of the local display showing the local IP aswell as the Broker used by the ESP32 (at the bottom of the screen)

1 Like

https://drive.google.com/drive/folders/1oTTaHoQWhAlI77lzhTBZC9XNSXaR1LBC?usp=sharing

here a link to the .INO file