Diy HC-05 bluetooth breakout board

HC-05 bluetooth module is a bluetooth transceiver that can be set to be either Master or Slave.
In the guide, I will explain how to transform a cheap Bluetooth HC-05 transceiver into a breakout board.


The version without a breakout board is a little cheaper but more difficult to solder to a breakout board.
You can view the board pinout on the images attached to this article.
In my version, i had changed the order of the pins because it was easier to solder. You can skip all the LEDs if you want to reduce power consumption but they are usefull for troubleshooting.

Materials needed:

  • HC-05 bluetooth module
  • small PCB
  • 3mm red LED
  • 3mm green LED
  • 6 pin header
  • soldering iron
  • solder

The pinout of the breakout board will be:

  1. Ground – make a connection between the breakout GND pin to the one of the ground pins of the HC-05 bluetooth module.
  2. Vcc – connect it to Vcc pin of the module. You should power the module with 3.3v
  3. Rx – connect it to Rx pin of the bluetooth module
  4. Tx – connect it with the Tx pin of the module
  5. KEY – connect it to PIO11 pin of the module
  6. STATE – connect it with PIO9 pin of the module and to the positive leg of the greeen LED

The STATE pin will be LOW when the HC-05 is not paired/connected and HIGH when the HC-05 is connected so we can use a green LED to indicate when there is an active connection.
The PIO8 can be used to monitor the status of the connection, so we will solder it to a yellow LED (to longer leg).
When the module will be powered, the yellow led will blink very fast, but after a connection was made, this led will blink slowly.

After done soldering, you can test the module using it to control a DC motor using Arduino .

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