CIRCUIT DIAGRAM WIRELESS TRANSMITTER

WIRELESS RECEIVER

CIRCUIT DIAGRAM DESCRIPTIONComponents Included•MCU: PIC167877A with 8K Bytes Program Flash, 368 Bytes SRAM data ,256 Bytes of EEPROM•One 6V EM Relay •I2C based Serial EEPROM AT24C16•RTC DS1307 with 56Byte NV RAM•LCD 16x2 display with backlight contrast adjustment •RS232 DB9 connector for System Interface • 11.0592Mhz crystal oscillator •RF Transmitter and Receiver Module(433.92 Mhz)•Temperature sensor (LM 35)

CIRCUIT DIAGRAM DESCRIPTION:The fire sensor input is given to the analog channel of the PIC controller and it is been converted and monitored by the PIC and it is displayed in the LCD. Whenever the fire is detected then the data is transmitted through the RF transmitter module and it is received in RF receiver module and according to the data the robot is moved and on the way if any bomb is detected through the proximity sensor then a alarm is heard and a indication also displayed in the LCD. The LCD is connected to the PORTD and PORTE of PIC16f877a.The temperature sensor is connected to the analog channel at RA0.The wireless module is connected at PIC16f877a transmission and reception pin.The motor driver are connected to the PORTB pinsThe BUZZER is connected to the PORTC.0 pin.

Microchip PIC16F877 Microcontroller FEATURES High-Performance RISC CPU:•Only 35 single-word instructions to learn•All single-cycle instructions except for program branches, which are two-cycle•Operating speed: DC – 20 MHz clock input DC – 200 ns instruction cycle•Up to 8K x 14 words of Flash Program Memory,•Up to 368 x 8 bytes of Data Memory (RAM),

Peripheral Features:•Timer0: 8-bit timer/counter with 8-bit prescaler•Timer1: 16-bit timer/counter with prescaler, can be incremented during Sleep via external crystal/clock• Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler• Two Capture, Compare, PWM modules

Capture is 16-bit, max. resolution is 12.5 nsCompare is 16-bit, max. resolution is 200 nsPWM max. resolution is 10-bit

• Synchronous Serial Port (SSP) with SPI™ (Master mode) and I2C™ (Master/Slave)• Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI) with 9-bit address detection• Parallel Slave Port (PSP) – 8 bits wide with external RD, WR and CS controls (40/44-pin only)• Brown-out detection circuitry for Brown-out Reset (BOR)

Analog Features:•10-bit, up to 8-channel Analog-to-Digital Converter (A/D)•Brown-out Reset (BOR)•Analog Comparator module with Two analog comparators•Programmable on-chip voltage reference (VREF) module•Programmable input multiplexing from device inputs and internal voltage reference•Comparator outputs are externally accessible

PIC16F877A BLOCK DIAGRAM AND PIN DESCRIPTIONPIN Diagram

TWS-434: The transmitter output is up to 8mW at 433.92MHz with a range of approximately 400 foot (open area) outdoors. Indoors, the range is approximately 200 foot, and will go through most walls.....The TWS-434 and RWS-434 are extremely small, and are excellent for applications requiring short-range RF remote controls. The transmitter module is only 1/3 the size of a standard postage stamp, and can easily be placed inside a small plastic enclosure.

The TWS-434 transmitter accepts both linear and digital inputs, can operate from 1.5 to 12 Volts-DC, and makes building a miniature hand-held RF transmitter very easy. The TWS-434 is approximately the size of a standard postage stamp.

RF Module TX/RX with HT12E & HT12D

TWS-434 Pin Diagram

RWS-434:

The receiver also operates at 433.92MHz, and has a sensitivity of 3uV. The RWS-434 receiver operates from 4.5 to 5.5 volts-DC, and has both linear and digital outputs.

RWS-434 Pin Diagram

Sample Receiver Application Circuit

Driving Relays:

Using the outputs of the HT-12D or HT-648L decoder ICs to drive relays is quite simple. Here are schematics showing how to drive relays directly from the data-output pins of the decoder.

NPN Relay Driver Circuit

PNP Relay Driver Circuit

2. TEMPERATURE SENSOR

Temperature sensor (LM35) used to sense the temperature. The LM 35 is the temperature sensor with the sensitivity of 10mv/ ‘c.LM 35 pin diagram

3. RELAY INTERFACE A 6V EM Relay is connected to the processor through RC1/CCP1 pin through BC547 Driver transistor. When the RC2 pin is switched high, the relay will be turned ON. The Relay output COM , NC and NO are terminated respectively through JP10 FRC Connector which can be extended for external applications.

3. MAX-232 Serial Interface

RS232 System InterfaceThe MAX232 Serial driver is used for system Interface.

The Tx and Rx line of the processor is connected to the T1IN and R1OUT pin the Serial driver. The TXD and RXD pin of the serial driver is connected to the 2 and 3 pin of the DB9 connector and this connector is used for system interface

4. DS1307 RTC InterfaceThe DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM.Address and data are transferred serially through an I2C*, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year

5. LCD DISPLAY INTERFACE The LCD can be interfaced to the processor using the JP13 connector. RB0, RB1 and RB2 pin of the processor is onnected to the RS,R/W and EN pin of the display. The RD0:RD7 pin of the processor will act as a data line and is connected to the D0:D7 pin of the Display. The Below fig shows the LCD Connection diagram.

6. MOTOR DRIVE UNIT

The system consists of two separate dc motor which are kept for symmetric and angular movement of the robot. For driving these two independent motors a H-bridge motor driver is used. The microcontroller output is given to the pins IN1A, IN1B, IN2A and IN2B input pins of L293 D motor driver IC. These pins are given to a control logic unit. These logic input terminals control each H-bridge output..

7. POWER SUPPLY