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Topic: MQTT void callback, nothing happens (Read 54 times) previous topic - next topic

Hello,

I'm testing with my arduino and MQTT cloud.
For the publish everything goes well, the arduino publishes "hello world"

But with the void callback function nothing happens.
With my MQTT.fx client, I'm subscribed to the topics "status" and "commando".
At the "status" I see that the arduino is a live.

When I publish with my MQTT.fx client to the topic "commando".
I can see it arrived in my client, but not in the serial monitor of the arduino.

Why is the void callback function not used?

Code: [Select]

#include <SPI.h>
#include <PubSubClient.h>
#include <Ethernet.h>

#define server "m20.cloudmqtt.com"
int port = 13365;

// Update these with values suitable for your network.
byte mac[]    = {  0xDE, 0xED, 0xBA, 0xFE, 0xFE, 0xED };
byte ip[]     = { 192, 168, 0, 120 };

unsigned long time;
char message_buff[100];

EthernetClient ethClient;
PubSubClient client(server, port, callback, ethClient);

void setup()
{
  // init serial link for debugging
  Serial.begin(115200);
 
  Ethernet.begin(mac, ip);
  if (client.connect("arduino-MQTT","test","test")) {
    client.publish("/arduino/status/","hello world");
    client.subscribe("/arduino/commando/");
    Serial.println("Connected");
  }
 
  if (Ethernet.begin(mac) == 0)
  {
      Serial.println("Failed to configure Ethernet using DHCP");
      return;
  }
}

void loop()
{
  // MQTT client loop processing
  client.loop();
}


void callback(char* topic, byte* payload, unsigned int length) {
 
  if (strcmp(topic, "/arduino/commando/") == 0) {
    String msg = toString(payload, length);
    Serial.println(msg);
  }else{
    Serial.println("arduino topic not found");
  } 
}

//
// toString function
//
String toString(byte* payload, unsigned int length) {
  int i = 0;
  char buff[length + 1];
  for (i = 0; i < length; i++) {
    buff[i] = payload[i];
  }
  buff[i] = '\0';
  String msg = String(buff);
  return msg;
}

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