Hello
I want to do a simple app that will do like that:
in press of a button, the app will trigger text box on.
this place will filled with some text from the arduino.
How to do that arduino will send text to the app and it will place it into the text box? and not the opposite? I saw only opposite - data from app turn on led.
I saw this block, but what is number of bytes? what i need to put into? i saw somene put -1 but didnt understand why.
The project that im trying to make:
arduino uno with bluetooth, magentic card reader and relay.
i want to turn on something that will connected to the relay, after a card is swipped. the bluetooth is for send some data to app.