P2P communication

hi all and Happy New year.
I would establish a communication between Rpi and a smartphone. In other word I would control some input/output connected to Rpi using node-red dashboard displayed in the smartphone.
To do this, I'm using Rpi as hotspot (in this way I connect the smartphone directly to the Right wifi) .this method has some problem. for this reason i m searching for a solution where the Rpi (through node red) send some data directly to smartphone (using Bluetooth for example) and the dashboard is installed on the smartphone side.
any suggestions?
thanks a lot

What dashboard are you installing on the phone side then ? It will need to make a connection back to Node-RED to get the required information, and Node-RED will have to be configured to supply it in the correct format for whatever dashboard you choose to use. Hence why using a browser is often the simpler option as that knows how to talk and display the widgets. You could use the node-red-contrib-uibuilder project to help get you started building your own dashboard which could be considerably lighter in terms of resources at your client/phone end.

You can in theory also run Node-RED locally on an Android device if it support Termux or similar app - see install instructions on the Node-RED site - but then you still need to send it data from your Pi.

What issues are you having with just using the default dashboard ?

thanks a lot for your contribution.
now the main issue is the following: when I connect the smartphone to wifi Rpi hotspot I have to disable the 4g connection (otherwise smartphone doesn't load the node red dashboard). since the Rpi doesn't share internet connection, smartphone loses the Internet connection.