Send data from cayenne to arduino possible ?!

yes, uso tranquillamente cayenne da anni,per conferma ho provato ha inserire tutto sul’ hardware nuovo e cmq fuziona con la prova base che hai dato ora

you mean, it works with pubsub also?

no con pubsub no

ho provato anche ad aprire le porte sul router ,ma niente

the port is not the issue here, as cayenne library code works.
Can you try this code and connect to any other MQTT broker https://github.com/knolleary/pubsubclient/blob/master/examples/mqtt_esp8266/mqtt_esp8266.ino

gia fatto, e fuzniona, mi dice che stampa

i did not get what you meant by above.

having done the test you posted to me, it works

which broker did you connect to?

broker.mqtt-dashboard.com

can you join me on http://slack.mydevices.com/

solved, my problem is that I inserted the device as GENERIC ESP8266 instead it must be inserted as ARDUINO GENUINO

You mean, while adding a new device, you needed to select a arduino device?

yes, if you don’t select an arduino device the sending won’t work with the sketch you gave me

Strange, anyways great debug.

technical question, in the schetch there is the payload variable that gives me the value I ask for. how do i get it out? that is, it comes out for example “temp, c = 22.0”
miserve insert this into a variable and send it
but I don’t understand the byte payload variable with for loop how to manipulate it

char buff[10];
void mqttCallback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    // Show the received message "stream" in the serial monitor.
    Serial.print((char)payload[i]);
    buff[i] = (char)payload[i];
  }
  Serial.println();
  Serial.print("buff:");
  Serial.print(buff);
  }