Hi guys. i am trying to make an android application that can publish messages to node red trough the mqtt subscriber node but i dont know what is the code of the application that can help me do that. can anybody help me please ?
Do you mean you want help with developing an Android app which publishes to mqtt? I think you would be better asking that on an Android forum.
However there are a number of mqtt apps for Android available, one of those may be useful to you.
This is not particularly Node Red related but I have done something similar using MIT App Inventor 2 and an MQTT extension
It works great
i used this solution and it worked for me