Video Link http://electronicsprojectsludhiana.com/videos/rf-control-device/
In this project we will control devices using RF technology. We can control no. of devices.
The project is to control the electrical/electronics devices through RF remote control which is built using HT12E and HT12D chips. The remote control is built using RF encoder chip HT12E that will generate different codes. These codes will be transmitted by 434 MHz RF transmitter. At the receiving side these codes will be received by 434 MHz RF receiver and decoded by RF decoder chip HT12D. These codes are fed to 89C51 to take a controlling the relay drive circuit or triac circuit.Triac or relay will control 220v devices.
In this project we show that how we design a RF system to control. In this project we use 12v relay 400 ohm for running controlling devices. In this project we use 89c51 microcontroller as a main processor. We use this processor to run the vehicle. This controller is basically a 40 pin ic. In this project we use two sensor also. These sensor are connected to the port p3.4 and port p3.5
In this project we will make a transmitter for RF data transmission. Pin no 1of RF tx module is ground . second is for data , third for VCC and fourth for antenna Transmitter.
Working:
RF transmitter – RF remote control which is built using HT12E and HT12D chips. The remote control is built using RF encoder chip HT12E that will generate different codes. These codes will be transmitted by 434 MHz RF transmitter. At the receiving side these codes will be received by 434 MHz RF receiver and decoded by RF decoder chip HT12D. In the transmitter side which will attach with car we will sensor for accident detection. Sensors will give signal to HT12E . HT12E is a 18 pin ic. It converts bit data input to serial output. It has 12 address lines to send data to particular receiver.
RF receiver- Output of HT12D connected to MCU at port pin no 1 to 4. In this project we are using UHF frequencies of RF. LED’s connected at port 2 pin p2.0,p2.1,p2.2,and p2.6. LCD rs, rw ,en connected to p2.5,p2.4 and p2.3.HT12 E and HT12D ‘s pin 1 to 9 connected to ground giving low. These are address pins of HT12E and HT12D. Pin no 10 to 14 of HT12 E are inputs of IC and 17 no pin is output pin. Pin no 10 -14 of HT12D is ouput pin and 14 is input pin. Crystal pin of HT12E is 15 and 16 .this project we will make one transmitter and RF receiver. RF remote control which is built using HT12E and HT12D chips. The remote control is built using RF encoder chip HT12E that will generate different codes. These codes will be transmitted by 434 MHz RF transmitter. At the receiving side these codes will be received by 434 MHz RF receiver and decoded by RF decoder chip HT12D.
89S52 MICRCONTROLLER.
89S52 MICROCONTROLLER. Is a 40 pin version of 51 family,. Program written for this controller is same for the 8051 controller. In this controller there is total 32 input and output pins. For controlling the process control.
OPTOCOUPLER ( PC 817) In this project we use optocoupler to provide a electrical isolation between process control circuit and motor drive circuit. In this project we use separate supply for processor and control circuit. Pc 817 is 4 pin ic. In this coupler two pin is input and two pin is output.
CRYSTAL. In this project we use two crystal. One for the dtmf decoder and second with the microcontroller Main use of the crystal is to provide a external frequency for the internal oscillator. With the dtmf decoder we use crystal 3.58 Mhz and with the microcontroller we use 12 Mhz crystal.