[SOLVED] Blynk Board Project #13

Hi there,

I just purchased a Blynk Board, and I have a question regarding virtual pins. The tutorial specifically instructs me to connect the terminal chat to V21, and a Value Display to V25. Connected to the Blynk board is a magnetic door switch set, from 3.3V to pin 16. And as I supposed, everything worked correctly… But I do not know why.

Why does the value display know to say ‘Open’ or ‘Close’? Is that the value that the magnetic switch sends? If so, why is V25 connected to pin 16 for that information to be relayed? Why does the terminal chat need to be connected to V21, and how does that know to print what it does?

I apologize if this is a rather simple concept I am missing, but I appreciate any and all help. Thanks,


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The virtual pin is just abstraction. In general, you may map any virtual pin to any real pin - http://help.blynk.cc/blynk-basics/what-is-virtual-pins

This is because SparkFun prepared ready sketches for you with pre-flashed pin numbers.

As I said before you can use any pin. It does know what it does because this behavior is programmed in the sketch.

Ah, so the Blynk board has been pre-programmed… How could I program it myself? In an arduino sketch? Thank you so much for the help.

Yes. You may start from Arduino IDE.

When I upload a sketch, am I uploading it to my blynk board, or an Arduino that is connected to a blynk board? Or could i theoretically do both?

To Blynk Board. Arduino is just providing you with IDE.

When uploading a sketch, what I know to change the port to the Blynk Board, but what “Board” setting should be selected?


Thank you, Dmitriy for all the help!

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