ESP8266 Community Forum

- Sat Dec 31, 2016 7:17 am #60194 Hello

I like to create a neopixel (24 ledring) gauge with an esp8266 with mqtt.
Like to use pubsubclient to subscribe to 4 topics
1) color1 (string) hex color (first color)
2) color2 (string) hex color (second color
3) gauge (int) value
4 mode (string) gauge mode (different mode types like fading color, etc...
But i have no idea how to get pubsubclient subscribe to 4 mqtt topics.

Can anyone set me in a good direction

Like to use this script

Code: Select all#include <ESP8266WiFi.h>
#include <PubSubClient.h>

// Update these with values suitable for your network.

const char* ssid = "........";
const char* password = "........";
const char* mqtt_server = "broker.mqtt-dashboard.com";

WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;

void setup_wifi() {

  delay(10);
  // We start by connecting to a WiFi network
  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());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  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') {
    digitalWrite(BUILTIN_LED, LOW);   // Turn the LED on (Note that LOW is the voltage level
    // but actually the LED is on; this is because
    // it is acive low on the ESP-01)
  } else {
    digitalWrite(BUILTIN_LED, HIGH);  // Turn the LED off by making the voltage HIGH
  }

}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("ESP8266Client")) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("outTopic", "hello world");
      // ... and resubscribe
      client.subscribe("inTopic");
    } 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() {
  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

void loop() {

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

  long now = millis();
  if (now - lastMsg > 2000) {
    lastMsg = now;
    ++value;
    snprintf (msg, 75, "hello world #%ld", value);
    Serial.print("Publish message: ");
    Serial.println(msg);
    client.publish("outTopic", msg);
  }
}

- Sat Dec 31, 2016 8:27 pm #60220 I think I foundation solution. De
Is this the wat tot do it ?

Code: Select allvoid callback(char* topic, byte* payload, unsigned int length) {

  String receivedtopic = topic;
  String receivedpayload ;
 
  for (int i = 0; i < length; i++) {
    receivedpayload += (char)payload[i];
  }
 
  Serial.print(receivedtopic);
  Serial.print(" => ");
  Serial.println(receivedpayload); 

  if ( receivedtopic == "inside") {
    lcd.setBacklight(HIGH);
    lcd.display();
    lcd.home (); // set cursor to 0,0
    lcd.print ("Inside is: ");
    lcd.setCursor (13, 0);
    lcd.print(receivedpayload);
  }

  if ( receivedtopic == "outside") {
    lcd.setCursor (0, 1);
    lcd.print ("Outside is: ");
    lcd.setCursor (13, 1);
    lcd.print(receivedpayload);
  }
}