My arduino with ethernet sheild W5100 cannot connect to cayenne


My devices : Arduino Mega 2560 with W5100 ethernet shield

Web Dashboard

this is my code .

This example shows how to connect to Cayenne using an Ethernet W5100 shield and send/receive sample data.

The CayenneMQTT Library is required to run this sketch. If you have not already done so you can install it from the Arduino IDE Library Manager.


  1. Set the Cayenne authentication info to match the authentication info from the Dashboard.
  2. Compile and upload the sketch.
  3. A temporary widget will be automatically generated in the Cayenne Dashboard. To make the widget permanent click the plus sign on the widget.

//#define CAYENNE_DEBUG // Uncomment to show debug messages
#define CAYENNE_PRINT Serial // Comment this out to disable prints and save space
#include <CayenneMQTTEthernet.h>

// Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
char username[] = “xxxxxxxxxxxxxxxxxxxxxxxxx”;
char password[] = “xxxxxxxxxxxxxxxxxxxxxxxxx”;
char clientID[] = “xxxxxxxxxxxxxxxxxxxxxxxxx”;

void setup() {
Cayenne.begin(username, password, clientID);

void loop() {

// Default function for sending sensor data at intervals to Cayenne.
// You can also use functions for specific channels, e.g CAYENNE_OUT(1) for sending channel 1 data.
// Write data to Cayenne here. This example just sends the current uptime in milliseconds on virtual channel 0.
Cayenne.virtualWrite(0, millis());
// Some examples of other functions you can use to send data.
//Cayenne.celsiusWrite(1, 22.0);
//Cayenne.luxWrite(2, 700);
//Cayenne.virtualWrite(3, 50, TYPE_PROXIMITY, UNIT_CENTIMETER);

// Default function for processing actuator commands from the Cayenne Dashboard.
// You can also use functions for specific channels, e.g CAYENNE_IN(1) for channel 1 commands.
CAYENNE_LOG(“Channel %u, value %s”,, getValue.asString());
//Process message here. If there is an error set an error message using getValue.setError(), e.g getValue.setError(“Error message”);


uncomment this //#define CAYENNE_DEBUG and check your serial monitor for any error. post a screenshot of your serial monitor.



It was error since i compile in arduino ide .


I can connect now. Thank you so much .:smiley:


Hi guys,

I got a similar problem as realplastic01 and I am using the exact same Hardware.

Are there any special settings I have to set on my internet connection?



I don’t have any issue to connect at this time.
Could you please check again ?


Hey eptrak,

I was trying now at a different location. The solution is quiet simple. At the first location I think that the port: 1883 is not open. (I know really dumb and faulty of mine). At home I am able to open port 1883.
So for all make sure ur internet router allows traffic via port 1883