I'm developing an application that communicates with Arduino (Arduino Uno), I used two ways to communicate so far, via :
1. USB (I used the usb-serial-for-android and Physicaloid libraries) and
2. Bluetooth, sending and receiving data.
Via Bluetooth was a little slow and sometimes the information was simply not sent or received, the USB communication sending data was pretty fast, but still, sometimes the connection does not open, and it's very random, run the application and USB connection does not open, close the application, run again and the connection open, have not tried connecting via Wifi.
My question is this, what is the ideal and safest way to perform connection with Arduino?
Bluetooth connection is best, because HC05 adapters are dirt cheap and those use UART for communication (the same as com- port )