Interfacing Android Phone with Microcontroller

The field of wireless communication is enormous and demands modernization. This proposed system that aims to interface android with microcontroller via Bluetooth, exposes lots of methods to work in this field. The project creates communication between an android mobile and microcontroller by enabling it to transmit and receive inflation and then by android mobile to simply control other devices which are connected to the microcontroller. The method of interfacing android with microcontroller through the Bluetooth device will help to develop this project named “android based smart phone used for induction motor control” because, in this project android mobile is interfaced with the microcontroller through the Bluetooth. This project is designed to control the speed of an induction motor like fan using an Android based smart phone. In home automation-related applications, the convenience of remotely controlling the speed of a fan can be achieved.

What is an Android Mobile?

The Android phone is nothing but it is a power full high-tech smart phone, and it runs on the android operating system. It is developed by the Google and it is used by different smart phone companies.

Microcontroller

The microcontroller is a small computer on a single integrated circuit. The typical microcontroller includes a processor, memory, and peripherals. It is designed to govern the operations of embedded systems in motor vehicles, robots, mobile radio transceivers and etc. There are different types of sizes in microcontroller like 32 bit, 16, bit, and 8 bit.

Block Diagram of the Interfacing Android Phone with Microcontroller

The hardware components required for this block diagram are seven segment display, 8051 microcontroller, Bluetooth device, voltage regulator, transformer, Opto oscillator, and LED. In this the remote operation takes place by any smart phone, Android device, tablet and a graphical user interface. The Android mobile is used as a transmitter through Bluetooth. If the transmitted data is received by the Bluetooth receiver is interfaced to the 8051 family microcontroller.

Every time the data is sent by the android application to deliver the delay firing pulses to the thyristor with the help of the optical isolation. The load power is connected in series with the thyristor and based on the received signal it is controlled. The firing angle is displayed on the seven segment display. A lamp load, whose varying intensity demonstrates the varying power to the motor for speed control, is provided in the place of the motor.

Further, this project can be improved by adding the number of outputs to the microcontroller feeding relay drives to switch on & off the domestic loads together with speed control of the fan.

Step Down Transformer

Generally the step down transformers are used to step down the high voltage to the low voltage like 11000V to 220V or 110V, and from 220V to 110V, 10, 12, 20, 24 volts etc. The basic structure of the step down transfer is shown below.

There are two types of windings in the step down transformer, which are primary & secondary winding. The induced EMF in the secondary winding is directly proportional to the number of turns on both windings of primary & secondary.

Bridge Rectifier

It is a circuit which converts the AC voltage into DC voltage by using the both half cycles of the input AC voltage. This circuit consists of four diodes in the form of bridge and the circuit of bridge rectifiers is shown below.

The AC input voltage is applied to the diagonally opposite to the bridge and for other two ends a load resistor is connected. In the positive half cycle of the AC input voltage D2 & D4 diodes are conducted and the D1 & D3 diodes are in OFF state. Therefore the conducting diodes are in the series with the load resistor hence the load current flows through the load resistor.

 Opto Isolator

It is a component used to transfer the electrical signals between the two isolated circuits with the help of light. The Opto isolator consists of an LED and phototransistor in the same opaque package and we can see in the following image. This isolator prevents the high voltage from affecting the system receiving the signal and the speed of the voltage transient is up to 10KV.

Applications

• The operation is in remote condition
• It can used in the smart offices
• It is totally based on the app based
• This can be extended to the IOT projects where it can also be operated in remote

Advantages

• It will reduce the human effects
• It is very easy to operate because its operation is ion android OS
• Electric shock is avoided

This article will give the information on interfacing android mobile with the microcontroller. I hope by reading this article you have gained some basic information about the interfacing of android mobile with a microcontroller. If you have any queries about this article about the andriod based projects, please feel free to comment in the below section. Here is the question for you, what the functions of the microcontroller?