5 Volts from Arduino pro mini TO 3.3 Volts HC-05 BTBEE module

hi , my project is Text files transferring through Bluetooth from a micro SD card to andriod mobile and
I have used Arduino pro mini AT328P 5 Volts 16 M Hz

I need to give the voltage of 3.3 volts for my Bluetooth module from Arduino pro mini (Arduino pro mini doesn’t have a 3.3 volts power supply pin)

I need a voltage regulator for converting 5 volts to 3.3 volts exactly , any circuite ?

1.Arduino promini powerd using FTDI1427 USB ( plese look at the attached: FTDI to Arduino Pro)

  1. HC-05 BTBEE bluetooth module data sheet (attachment BTBEE)

  2. I have tried LM317 voltage regulator my Bluetooh module got power( RED LED) up but status (GReen LED) is not blinking , this voltage regulator is producing 3 volts only ( attachment )

BTBEE-V1.0 datasheet.pdf (375 KB)

Voltage regulator.PNG

Either get (or build) a logic level converter or just buy one: http://www.aliexpress.com/item/Free-shipping-4-channel-IIC-I2C-Logic-Level-Converter-Bi-Directional-Module-5V-to-3-3V/32308653416.html

Your other option is to switch to 3.3V arduino mini - if you do that remember to get a 3.3V FTDI adapter is your current 5V one won't work with it.

I have used an LM317 variable voltage regulator to drop the 5v to 3.3v.


Use the same regulator and a couple of caps, same as an Uno. Promini regulator is only good for 150mA, don't take that 5V and make 3.3V from it.

It might be simpler, and no more expensive to ditch the module and get a plain vanilla HC-05 on a JY-MCU board that will run on 5v.

The item you refer to is an HC-06 anyway, which may be OK for your needs, but may not be in the long run.

I made it , i have used the same LM317 voltage regulator and now my Bluetoth module is working fine

Attached circuite is producing the 3.4 volts for input of 5 volts ( Note : 0.1U F is ceramic capacitor & 1UF is electrolyte capacitor)

voltrage rgltr.PNG