B4J Question Interfacing with Raspberry PI/PiFace with Android phone

[giggetto71]

Hi All,
I am super new to B4J and I would like to create a simple test app to read inputs and set outputs from/to the raspberry via an Android App running on a phone. I have read many forums and threads but I am more and more confused. What is the "cleanest" architecture? I was thinking to: develop with B4J an app running on Raspberry to handle the Low level I/O interface and the communication layer with the Android app. The I/O portion does not seem too complicated (didn't try yet..just a feeling) but I am confused about the communication layer. Should that be a web server responding to web clients (the android app) or should I go for a MQTT broker running on the raspberry responding to MQTT clients call from the Android App (coded with B4A) running on the phone?
Can someone provide some guidance? THANKS!!!!!
pierluigi

 

[Erel]

Both options (server running on the RPi or MQTT broker running somewhere) are possible.

MQTT is a bit simpler to use.

 

[giggetto71]

Erel,
thanks. I was able to run an MQTT broker and client on the raspberry. Now I would like to run an MQTT client on an Android app (BTW, does it have to be a physical device or I can use an emulator?). Is there a post in this community that you are aware of where I could start from? I mean is there already a B4A example where I can see how to implement a client that talks over the local network to the broker running on my raspberry?
thanks!!

 

[Erel]

I mean is there already a B4A example where I can see how to implement a client that talks over the local network to the broker running on my raspberry?

https://www.b4x.com/android/forum/pages/results/?query=b4a+mqtt