Hello, I got on my serial port info that ESP8266 (wemos d1 mini) can’t connect to MQTT Server ;/ [but It connectet to my WIFI successfuly]
Got it from COM5
Attempting MQTT connection...failed, rc=-4 try again in 5 seconds
Attempting MQTT connection...failed, rc=-4 try again in 5 seconds
and so on.....
#ifdef ESP8266
#include <ESP8266WiFi.h>
#elif defined(ESP32)
#include <WiFi.h>
#else
#error "Board not found"
#endif
#include <PubSubClient.h>
#include <ModbusRTU.h>
#define SLAVE_ID 2
#define Relay1 0x001
#define Relay2 0x002
#define Relay3 0x003
#define Relay4 0x004
#define Relay5 0x005
#define Relay6 0x006
#define Relay7 0x007
#define Relay8 0x008
#if defined(ESP8266)#include <SoftwareSerial.h>
// SoftwareSerial S(D1, D2, false, 256);
// receivePin, transmitPin, inverse_logic, bufSize, isrBufSize
// connect RX to D2 (GPIO4, Arduino pin 4), TX to D1 (GPIO5, Arduino pin 4)
SoftwareSerial S(3, 1); // 3 - RX, 1 - TX Wemos D1 Mini
#endif
int DE_RE = 5; // For MAX485 chip
ModbusRTU mb;
bool cbWrite(Modbus::ResultCode event, uint16_t transactionId, void * data) {
#ifdef ESP8266
Serial.printf_P("Request result: 0x%02X, Mem: %d\n", event, ESP.getFreeHeap());
#else
Serial.print("Request result: 0x");
Serial.print(event, HEX);
#endif
return true;
}
// NETWORK CONNECTION
const char * ssid = "xx";
const char * password = "xxxxx";
const char * mqtt_server = "7e2xxxxxxxxxxxxx71a.s1.eu.hivemq.cloud"; // Local IP address of Raspberry Pi or cloud mqtt broker
const char * username = "xxxxxxxxxx";
const char * pass = "xxxxxxxxxxxxxxx";
// Subscribed Topics
#define sub1 "device1/relay1"
#define sub2 "device1/relay2"
#define sub3 "device1/relay3"
#define sub4 "device1/relay4"
#define sub5 "device1/relay5"
#define sub6 "device1/relay6"
#define sub7 "device1/relay7"
#define sub8 "device1/relay8"
WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
#define MSG_BUFFER_SIZE(50)
char msg[MSG_BUFFER_SIZE];
int value = 0;
// Connecting to WiFi Router
void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting 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("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void callback(char * topic, byte * payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
if (!mb.slave()) {
if (strstr(topic, sub1)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the LED if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0001, 0x0100, cbWrite); // 0x001 - relay 1, 0x002 - relay 2 and so on
// 0x0100 - turn on relay, 0x0200 turn off relay
} else {
mb.writeHreg(SLAVE_ID, 0x0001, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub2)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0002, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0002, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub3)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0003, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0003, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub4)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0004, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0004, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub5)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0005, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0005, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub6)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0006, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0006, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub7)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0007, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0007, 0x0200, cbWrite); // turn off the light
}
} else if (strstr(topic, sub8)) {
for (int i = 0; i < length; i++) {
Serial.print((char) payload[i]);
}
Serial.println();
// Switch on the light if an 1 was received as first character
if ((char) payload[0] == '1') {
mb.writeHreg(SLAVE_ID, 0x0008, 0x0100, cbWrite);
} else {
mb.writeHreg(SLAVE_ID, 0x0008, 0x0200, cbWrite); // turn off the light
}
} else {
Serial.println("unsubscribed topic");
}
}
mb.task();
yield();
}
// Connecting to MQTT broker
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Create a random client ID
String clientId = "ESP8266Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str(), username, pass)) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("outTopic", "hello world");
// ... and resubscribe
client.subscribe(sub1);
client.subscribe(sub2);
client.subscribe(sub3);
client.subscribe(sub4);
client.subscribe(sub5);
client.subscribe(sub6);
client.subscribe(sub7);
client.subscribe(sub8);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
Serial.begin(115200);
#if defined(ESP8266)
S.begin(9600, SWSERIAL_8N1);
mb.begin( & S, DE_RE);
mb.master();
#endif
setup_wifi();
client.setServer(mqtt_server, 8883);
client.setCallback(callback);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
}
I use HiveMQ free cloud mqtt broker
In my HiveMQ console I got port 8883 (TLS ), and the url which I put on my node-red node mqtt-broker-node in server attribute and the port 8883 and clicked “Use TLS” and in the Secruity label I enter username and password and I put in on my esp’s code.
const char * mqtt_server = "7e2xxxxxxxxxxxxx71a.s1.eu.hivemq.cloud"; // Local IP address of Raspberry Pi or cloud mqtt broker
const char * username = "xxxxxxxxxx";
const char * pass = "xxxxxxxxxxxxxxx";
// Connecting to MQTT broker
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Create a random client ID
String clientId = "ESP8266Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str(), username, pass)) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("outTopic", "hello world");
// ... and resubscribe
client.subscribe(sub1);
client.subscribe(sub2);
client.subscribe(sub3);
client.subscribe(sub4);
client.subscribe(sub5);
client.subscribe(sub6);
client.subscribe(sub7);
client.subscribe(sub8);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
setup_wifi();
client.setServer(mqtt_server, 8883);
client.setCallback(callback);
}
