Need Help with My Project: Failed to enable MUX

Hi, everybody,

I am using an ESP8266 to connect the Arduino Mega 2560 to my WiFi.

I managed to get it all working yesterday. Then all of a sudden, the serial monitor started spitting out errors which appear to show the module having trouble connecting to the cloud.

You’ve put “[SOLVED]” in the title of your topic. Does this mean that this topic can be closed?


haha… sorry for that… first time using this

I’d suggest that you post your code - correctly formatted with triple backticks at the beginning and end.
Triple backticks look like this:

Copy and paste them if necessary, code posted without the correct formatting will be deleted.


Here is mine coding… I have two ESP8266 for testing…
(for this coding)-When I am using ESP8266 (A) to connect Arduino Uno… it can work and connect with blynk successfully… but when i apply it to Arduino Mega (I have change the port and board already)… it show the ESP is no responding and also failed to enable MUX…
(for the same coding) - When ESP8266 (B) is connected with Arduino Uno… it show the ESP is no responding… But this ESP8266 (B) connect with Arduino Mega 2560 just have the problem with FAILED to enable MUX…
any idea abt this kind of situation? its that mine esp8266 flashed problem???

Are you saying that you have previously uploaded sketches to your ESP8266’s (I assume that they are actually ESP-01 boards)?


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yup~ you are right.

In that case, you have overwritten the factory “AT” firmware with your sketch.
To get them to work as WiFi modems again you will need to re-flash them with AT firmware, which can’t be done via the Arduino IDE.


Alright… I will try re-flash them. TQ @PeteKnight.