Automatic Room Light Controller
This Project “Automatic Room Light Controller with Visitor Counter using Microcontroller” is a reliable circuit that takes over the task of controlling the room lights as well us counting number of persons/ visitors in the room very accurately. When somebody enters into the room then the counter is incremented by one and the light in the room will be switched ON and when any one leaves the room then the counter is decremented by one. The light will be only switched OFF until all the persons in the room go out.
The total number of persons inside the room is also displayed on the seven segment displays. The microcontroller does the above job. It receives the signals from the sensors, and this signal is operated under the control of software which is stored in ROM. Microcontroller AT89S52 continuously monitor the Infrared Receivers, When any object pass through the IR Receiver’s then the IR Rays falling on the receivers are obstructed this obstruction is sensed by the Microcontroller.
BLOCK DIAGRAM OF PROJECT: [pic] COMPONENTS REQUIRED:
Voltage Regulator 7805 . Diode IN 4007 3. Relay 4. IR Tx/Rx Pair 5. 7 Segment Display 6. optical fiber cable Description of Microcontroller: 89s52: The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer.
By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel’s AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry.
In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM con-tents but freezes the oscillator, disabling all other chip functions until the next interrupt. [pic] The hardware is driven by a set of program instructions, or software.
Once familiar with hardware and software, the user can then apply the microcontroller to the problems easily. The pin diagram of the 8051 shows all of the input/output pins unique to microcontrollers: [pic]The following are some of the capabilities of 8051 microcontroller: ? Internal ROM and RAM ? I/O ports with programmable pins ? Timers and counters ? Serial data communication The 8051 architecture consists of these specific features: 16 bit PC &data pointer (DPTR) ? 8 bit program status word (PSW) ? 8 bit stack pointer (SP) ? Internal ROM 4k ? Internal RAM of 128 bytes. ? 4 register banks, each containing 8 registers ? 80 bits of general purpose data memory ? 32 input/output pins arranged as four 8 bit ports:P0-P3 ? Two 16 bit timer/counters: T0-T1 ? Two external and three internal interrupt sources ? Oscillator and clock circuits Applications: • Telecom:
Mobile phone system (handset and base station), modems and routers. • Automotive application: Braking system, tracking control, Airbag release system, management unit and Steer- by- wire systems . • Domestic application: Dishwasher, television, washing machine, microwave oven, video recorder, security system, garage door controller, calculator, digital watches, VCRs, digital cameras, remote control, treat mills. • Robotic: Fire fighting robot, automatic floor cleaner, robotic arm .
