ABSTRACT:

The main aim of the project is to design a versatile device that can control stepper motor by using RF technology of wireless communication. This device can be used to control the speed and direction  of the stepper motor.

The RF modules used here are STT-433 MHz Transmitter along with an RF encoder HT12E, STR-433 MHz Receiver along with an RF decoder HT12D.

The project is designed in such a way that a PC will be interfaced to the controller through serial communication, using which we will input the data to the controller using the hyper terminal of PC to control the motor. Here we will use a serial line driver IC MAX232   to interface the PC with controller. And for the visual effects, the front end will also be developed by using a good user interface software VB .NET to input the data to the controller through serial communication. The RF transmitter is also interfaced to the controller through an RF encoder to encode the data received by the controller and to transmit the data. Hence the encoded data will be transmitted by the transmitter over the wireless medium and will be received by the RF receiver which will be interfaced to the controller through an RF decoder, on the receiver side. The RF decoder is used to decode the received data into a 4 bit digital data which will be fed to the controller. And a stepper motor will also be interfaced to the controller through a driver IC ULN2003A. Now, it is the job of the controller to read the data received from the decoder and to  perform the predefined task of rotating the motor clockwise, anticlockwise and increasing, decreasing the speed of the stepper motor. 16X2 LCD is provided at the receiver side to display the status of the DC motor.

 This project uses regulated 5V, 500mA power supply. Unregulated 12V DC is used for relay. 7805 three terminal voltage regulator is used for voltage regulation. Full wave bridge rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.

TECHNICAL SPECIFICATIONS:

HARDWARE:

Micro controller         :           AT89S52

Crystal                        :           11.0592 MHz

LCD                            :           HD44780

RF transmitter             :           STT-433MHZ

RF receiver                 :           STT-433MHZ

RF encoder                 :           HT12E

RF decoder                 :           HT12D

Stepper motor

Driver IC                     :           ULN2003A

PC

Serial line driver IC    :           MAX232

Power supply

Transformer                :           12V step down 

Filter                           :           1000uf/25V

Voltage Regulator      :           7805

SOFTWARE :

Keil microvision

proteus

UC flash

APPLICATIONS: Industrial applications