Abstract
The main aim of the project is to design a versatile device that can control DC devices which draw up to a few amps of current. The circuit may be used in either 12 or 24 Volt systems with only a few minor wiring changes. This device has been used to control the speed of the DC motor and to control brightness of an automotive tail lamp.
The RF modules used here are STT-433 MHz Transmitter, STR-433 MHz Receiver, HT640 RF Encoder and HT648 RF Decoder. Switches are provided at the transmitter end, to control the speed and direction of the dc motor which is connected at the receiver side.
The switches are interfaced to the RF transmitter through RF Encoder. The encoder continuously reads the status of the switches, passes the data to the RF transmitter and the transmitter transmits the data. At the receiving end, the RF receiver receives this data, gives it to RF decoder. This decoder converts the single bit data into 8-bit data and presents it to the microcontroller. Now, it is the job of the controller to read the data and perform the corresponding action i.e., to rotate the dc motor clockwise, anticlockwise, increase or decrease the speed of the dc motor. 16X2 LCD is used to display the related messages.
SOFTWARE AND HARDWARE TOOLS:
Software Tools:
- Keil compiler
- Orcad.
- Proload
Hardware Tools:
- Microcontroller AT89S52.
- RF receiver and transmitter
- RF encoder and decoder.
- Switches
- LCD
- DC motor
Block diagram
Transmitter section
Receiver section
