Hi, I am very new in using Bluetooth module in Arduino
after watching a bunch of tutorials I have come to a conclusion that you must add a voltage divider in order to decrease 5V from the arduino to 3.3V and also not get your HC 05/06 fried
But why can't just people use the 3.3V pin in the arduino uno instead of making a voltage divider?
I am very new to this Bluetooth communication thing and I really want to learn please answer
I think that you misunderstand the use of the voltage divider. It has nothing to do with the power to the module. The voltage divider goes between the Arduino (5V) TX pin and the Bluetooth module (3.3V) RX pin to keep the input to RX under 3.3V. If the modules that you have say "power 3.6-6V" on the back, just power the module with 5V.
Thank you really help me, if my Bluetooth module still has "power 3-6V" at the back can I still put a voltage divider?
This is the widely used connection between UNO and HC-05/HC-06.
HC-05/HC-06 is a 5V module.
RX-pin is not 5V tolerant.
The voltage regulator is required (as shown in the diagram posted by GolamMostafa, shown below) when connecting a 5V TX from an Arduino board to the 3.3V RX of the Bluetooth module regardless of the module supply voltage.