guys, I am new to arduino. I am trying to power my HC-05 (5v with regulator to 3.3v) from Arduino Pro Mini 3.3v but I can't get it to power on.
There is a problem: The site I bought HC-05 from says that it needs 3.3-6 volts to power on but the back of HC-05 shows only 5v pin. To confirm that it runs only on 5v I need to connect it to external 5v supply.
But how do I make the connection? What do I connect to negative of the battery if I choose to externally power it?
Second Problem: If my HC-05 turns out to need only 3.3v input voltage, how many coins cells do I connect in series to power both pro mini and HC-05 module.
I am using a coin cell (3.3v) for powering the pro mini.