It's really easy and quick to add voice control to your arduino project. Whether it is home automation or door lock, or robots, voice control could be one eye catching feature in an arduino project. In this tutorial I"ll show you how to voice control arduino projects without voice recognition shield. We"ll be using a HC-05 Bluetooth module. We"ll connect a Android device with HC-05 Bluetooth. Android Phone will convert voice into string of data using Google voice recognition software. This string of data will be sent to HC-05 Bluetooth module and then to arduino uno. After that, Arduino decodes and process it.

Step 1: Connections

The circuit is very simple. Since the Tx and Rx pin on HC-05 bluetooth module are 3.3v pins you have use voltage dividers to step down 5 volt signal from arduino to 3.3 volt signal.

Arduino--------------- HC-05 Bluetooth

11--------------------------Rx

10--------------------------Tx

5v-------------------------Vcc

Gnd----------------------Gnd

Step 2: Coding

On the Android device we use an Application called as AMR_Voice to convert voice into string of data and send it over bluetooth. You can download this app from Google Playstore by clicking here.

We use the software serial library for this project. You can download the code, it is attached with this instructable.