No connection to arduino


Morning @rsiegel , I’m having connection problems with my Arduino Mega, since today at 5 am he lost connection and did not update any more. I already reset the arduino board and even without success. Was there something to be done?


Could you share the output from the Arduino IDE serial monitor while you’re attempting to connect?



I have 4 arduinos cards connected to Cayenne only 2 are working since 2h00 PM.
-the ethernet shield S5100 + arduino uno.
-wemos D1 connected by wifi.

my 2 others card can’t reach to connect to cayenne.

and so on…


Sorry the two cards that can’t connect are arduino uno + ESP01
and the second one is a arduino mega + ESP01.

it happen suddenly.
I think the server of cayenne is not working well.


Could you try connectivity of your Arduino device with one of our supported Ethernet or WiFi shields, or connectivity of the ESP8266 as a standalone device using the code from Add New > Device / Widget > MicroControllers > Generic ESP8266 ?

Connectivity using the ESP as a Wifi shield for some other Arduino device is not really officially supported, though I know we have many users doing so using the steps in this post. But because this is an un-official (at the moment) trick, I don’t think its a good place to start troubleshooting potential issues with our Arduino server. In fact it may be that explains why your Arduino/W5100 combo and Wemos --> Cayenne connection are working OK while your Arduino/ESP-as-shield combos are not.

Perhaps @kreggly has some ideas for troubleshooting those Arduino / ESP-as-shield combo devices?


Try running this sketch in Arduino serial passthrough example to talk directly to the esp and try some AT commands. make sure its getting a IP correctly. Ive had a esp-01 go “dumb” a couple times and default to wrong values.

AT+CWMODE_CUR=1 - puts in station mode
AT+CWLAP - lists access points
AT+CWJAP_CUR=, - join access point
AT+CIFSR - get ip address


It is also tricky which firmware is running on the ESP. Earlier ESP
firmware versions had issues.

Firmware version 1.0.0 (AT v0.22) or later is needed.

I have an ESP02 running fine, and ESP07, and ESP12s, but I have never tried
an ESP01.

Also critical are the connections to the device. ESP12s require an external
capacitor to keep from resetting themselves. We have had users have issues
where they have I/O configured improperly, driving lines that are meant as
input, or the config bits are just not set right, so on boot up you get
unreliable mode selection.

The Mega has multiple serial ports. I would try and pass the output of your
ESP to the serial monitor and see what kind of error messages you are
getting back. There is also an Arduino IDE add on for interpreting those
messages you can install.






thank for yours answers but I was fed up with this project I went running to empty my brain.

I’m back now.

As I said the server was away… I create a new connection to get a new “Auth Code”…

I don’t even change a letter of the code only the “Auth Code” it works well as before.