HC-06 pairing to arduino I have a bluetooth module HC-06 and want to pair it to my Arduino UNO. The thing is when I researched how to do so, I got different answers. What pairing should I use? Thank you in advance. I have highlighted the differences.

First version:
https://www.instructables.com/id/Add-bluetooth-to-your-Arduino-project-ArduinoHC-06/

HC-06>>>Arduino

VCC>>>>3.3v

GND>>>>GND

TXD>>>>RXD

RXD>>>>TXD

Second version:
http://42bots.com/tutorials/hc-06-bluetooth-module-datasheet-and-configuration-with-arduino/

HC-06            &lt;&lt;>> Arduino

HC-06 Ground GND &lt;&lt;>> GND

HC-06 VCC pin  &lt;&lt;>> 5v

HC-06 TX/TXD pin &lt;&lt;>> Arduino RX

HC-06 RX/RXD pin &lt;&lt; resistors >> Arduino TX

[![enter image description here][1]][1]

[![enter image description here][2]][2]
Which you use depends on two factors: the HC-06 carrier board you have, and which Arduino you are using.

If your carrier board has (and most do) a 3.3V regulator then you power the board from 5V.

If your Arduino is a 5V Arduino (such as an Uno) then you need a voltage divider on the (arduino)TX->(hc)RX pins otherwise you risk damaging the bluetooth module.