I was originally just testing my ESP8266 NodeMCU v3 board using a public broker. When I tried to make the change to my local MQTT server I changed the User_config.h file and uploaded to the board. However it seems the board is still connecting to the old server. How can I fix this?
Thanks.
Hello,
if you were using wifi manager maybe try to clean memory when you upload the program,
from the tools menu of the arduino ide choose “erase flash” and select “all flash contents”
Is there.a way to just erase fhe flash without erasing the OMGgateway firmware on the ESP8266? I want it to keep running the software it has, just get back to the wifi manager so I can re-enter the new MQTT gateway details.
It depends on the version you are using and your hardware setup,
if you stop your wifi, power on the gateway and wait for some time (I would say 10 minutes) the flash should be erased and the portal pop up.
With the version v0.9.3 you may send an mqtt message to erase it.
Blocking it from my wifi got it back to the wifi manager which allowed me to set the MQTT gateway again. Problem with sending the erase command through MQTT is that it only works if the device is connected to the MQTT broker 
I read something about holding down TRIGGER_PIN on one of the help pages but I was unclear which one that was on my ESP8266.