# Configure an AT-05 Bluetooth - Serial Adapter

## Overview
This module is a little bit cheaper than the other common ones, so I ordered two to evaluate them. Turns out the configuration is not that easy...

{{:elec:notes:at05_btmodule.jpg?direct&200 |AT-05 Bluetooth module}}
{{:elec:notes:at05_footprint.jpg?direct&200 |Footprint}}
{{:elec:notes:at05_schematic.jpg?direct&200 |Schematic}}

## Steps

* You need an Android device, and to download the Blue\_SPP chinese app. I wouldn't recommend using your phone or anything having access to personnal information, the required permissions are quite... large.
* Connect to the BLUE\_SPP bluetooth device, using 1234 as PIN and 115200 as baudrate.
* Enter the _command_ mode: `#AT#SET=***#` where *** is a multiple of 5 sec. 1 => 5s, 2 => 10s, ..., 9 => 45s (9 is the maximum value). I guess it's an inactivity timeout. Every successful command should be answered by "OK".
* Get the current parameters: `#AT#GET#`
* Set the name of the device: `#AT#NAME=newName#`
* Set the PIN code: `#AT#PIN=xxxx#`
* Change the MAC address: `#AT#MAC=xxxxxxxxxx#`
* Change the baudrate: `#AT#UART=B,S#` where:
  * B is the baudrate setting, between 0 and 8:
    * 0 => 2400
    * 1 => 4800
    * 2 => 9600
    * 3 => 19200
    * 4 => 38400
    * 5 => 57600
    * 6 => 115200
    * 7 => 128000
    * 8 => 256000
  * S represents the parity
    * 0 => No check
    * 1 => Odd
    * 2 => Even
* Check the new settings: `#AT#GET#`
* Exit the command mode: `#AT#SET=0#`
* Power-cycle the BT module to apply the new settings


## Links

* [[http://www.aliexpress.com/item/Yunhui-ATK-HC05-Bluetooth-serial-adapter-from-the-machine-51-single-Bluetooth-to-Serial-Communications-Module/2029576928.html|Aliexpress link, with info]]
* [[http://wiki.pinguino.cc/index.php/SPP_Bluetooth_Modules|Common SPP BT adapters]]