In this chapter, we will use another feature of Android devices to control an Arduino system: voice recognition. We will control a relay that is connected to an Arduino board by sending vocal commands from the phone.
This relay can be connected to many things. For example, it can be connected to an electric door lock so that you could open and close a door by just speaking into your phone. You can also connect the relay to a lamp, to switch the lamp on and off by giving a vocal command to your phone.
In this chapter, you will learn how to:
Connect a relay and a Bluetooth module to an Arduino board so that it can be controlled from the Android application
Build an application using the Android speech API
Control the relay on the Arduino board by voice