CHAPTER :- 1 Project Overview 1. Introduction Of Project 1. 1 Project Definition: Project title is “AUTOMATIC ROOM LIGHT CONTROLLER WITH BIDIRECTIONAL VISITOR COUNTER “. The objective of this project is to make a controller based model to count number of persons visiting particular room and accordingly light up the room. Here we can use sensor and can know present number of persons. In today’s world, there is a continuous need for automatic appliances with the increase in standard of living, there is a sense of urgency for developing circuits that would ease the complexity of life.
Also if at all one wants to know the number of people present in room so as not to have congestion. This circuit proves to be helpful. 1. 2 Project Overview 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 receiver are obstructed , this obstruction is sensed by the Microcontroller CHAPTER :- 2 BLOCK DIAGRAM AND ITS DESCRIPTION 2. 1Basic Block Diagram
Enter Exit Relay Driver A T 8 9 S 5 2 Signal Conditioning Exit Sensor Enter Sensor Light Signal Conditioning Power Supply Fig. 2. 1 Basic Block Diagram 2. 2 Block Diagram Description The basic block diagram of the bidirectional visitor counter with automatic light controller is shown in the above figure. Mainly this block diagram consist of the following essential blocks. 1. Power Supply 2. Entry and Exit sensor circuit 3. AT 89S52 micro-controller 4. Relay driver circuit 1. Power Supply:- Here we used +12V and +5V dc power supply. The main function of this block is to provide the required amount of voltage to essential circuits. 12 voltage is given. +12V is given to relay driver. To get the +5V dc power supply we have used here IC 7805, which provides the +5V dc regulated power supply. 2. Enter and Exit Circuits:- This is one of the main part of our project. The main intention of this block is to sense the person. For sensing the person and light we are using the light dependent register (LDR). By using this sensor and its related circuit diagram we can count the persons. 3. 89S52 Microcontroller:- It is a low-power, high performance CMOS 8-bit microcontroller with 8KB of Flash Programmable and Erasable Read Only Memory (PEROM).
The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the MCS-51TM instruction set and pin out. 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 Flash on a monolithic hip, the Atmel AT89S52 is a powerful Microcontroller, which provides a highly flexible and cost effective solution so many embedded control applications. 4. Relay Driver Circuit:- This block has the potential to drive the various controlled devices.
In this block mainly we are using the transistor and the relays. One relay driver circuit we are using to control the light. Output signal from AT89S52 is given to the base of the transistor, which we are further energizing the particular relay. Because of this appropriate device is selected and it do its allotted function. CHAPTER :- 3 SCHEMATIC DIAGRAM Transmission Circuit:- Fig. 3. 1 Transmitter circuit Receiver Circuit:- Fig. 3. 2 Receiver circuit * CIRCUIT DESCRIPTION: There are two main parts of the circuits. 1. Transmission Circuits (Infrared LEDs) 2. Receiver Circuit (Sensors) . Transmission Circuit: Fig. 3. 3 Transmitter circuit This circuit diagram shows how a 555 timer IC is configured to function as a basic monostable multivibrator. A monostable multivibrator is a timing circuit that changes state once triggered, but returns to its original state after a certain time delay. It got its name from the fact that only one of its output states is stable. It is also known as a ‘one-shot’. In this circuit, a negative pulse applied at pin 2 triggers an internal flip-flop that turns off pin 7’s discharge transistor, allowing C1 to charge up through R1.
At the same time, the flip-flop brings the output (pin 3) level to ‘high’. When capacitor C1 as charged up to about 2/3 Vcc, the flip-flop is triggered once again, this time making the pin 3 output ‘low’ and turning on pin 7’s discharge transistor, which discharges C1 to ground. This circuit, in effect, produces a pulse at pin 3 whose width t is just the product of R1 and C1, i. e. , t=R1C1. IR Transmission circuit is used to generate the modulated 36 kHz IR signal. The IC555 in the transmitter side is to generate 36 kHz square wave. Adjust the preset in the transmitter to get a 38 kHz signal at the o/p. round 1. 4K we get a 38 kHz signal. Then you point it over the sensor and its o/p will go low when it senses the IR signal of 38 kHz. 2. Receiver Circuit: Fig. 3. 4 Receiver circuit The IR transmitter will emit modulated 38 kHz IR signal and at the receiver we use TSOP1738 (Infrared Sensor). The output goes high when the there is an interruption and it return back to low after the time period determined by the capacitor and resistor in the circuit. I. e. around 1 second. CL100 is to trigger the IC555 which is configured as monostable multivibrator. Input is given to the Port 1 of the microcontroller.
Port 0 is used for the 7-Segment display purpose. Port 2 is used for the Relay Turn On and Turn off Purpose. LTS 542 (Common Anode) is used for 7-Segment display. And that time Relay will get Voltage and triggered so light will get voltage and it will turn on. And when counter will be 00 that time Relay will be turned off. Reset button will reset the microcontroller. CHAPTER :- 4 HARDWARE DESIGN ; DESCRIPTIONS Hardware Design:- Infrared Sensor TSOP1738 Microcontroller AT89S52 Relay 7-Segment Display Timer IC 555 Fig. 4. 1 Snap of the entire circuit 4. 1 Procedure Followed While Designing:
In the beginning I designed the circuit in DIPTRACE software. Dip trace is a circuit designing software. After completion of the designing circuit I prepared the layout. Then I programmed the microcontroller using KEIL software using hex file. Then soldering process was done. After completion of the soldering process I tested the circuit. Still the desired output was not obtained and so troubleshooting was done. In the process of troubleshooting I found the circuit aptly soldered and connected and hence came to conclusion that there was error in programming section which was later rectified and the desired results were obtained. . 2 List of Components: Following is the list of components that are necessary to build the assembly of the Digital Speedometer Cum Odometer: * Microcontroller – AT89S52 * IC – 7805 * Sensor – TSOP 1738 (Infrared Sensor) * Transformer – 12-0-12, 500 mA * Preset – 4. 7K * Disc capacitor – 104,33pF * Reset button switch * Rectifier diode – IN4148 * Transistor – BC 547, CL 100 * 7-Segment Display 4. 3 Description of Components 4. 3. 1 Microcontroller AT89S52: 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 pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory pro- grammar. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel 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 or hardware reset. FEATURES:- * 8 KB Reprogrammable flash. * 32 Programmable I/O lines. * 16 bit Timer/Counter—3. * 8 Interrupt sources. * Power range: 4V – 5. 5V * Endurance : 1000 Writes / Erase cycles * Fully static operation: 0 Hz to 33 MHz * Three level program memory lock * Power off flag * Full duplex UART serial channel * Low power idle and power down modes * Interrupt recovery from power down modes * 256 KB internal RAM * Dual data pointer 4. 3. 2TSOP1738 (INFRARED SENSOR)
Fig. 4. 2 Infrared Sensor Description: The TSOP17.. – Series are miniaturized receivers for infrared remote control systems. PIN diode and preamplifier are assembled on lead frame, the epoxy package is designed as IR filter. The demodulated output signal can directly be decoded by a microprocessor. TSOP17.. is the standard IR remote control receiver series, supporting all major transmission codes. Features: * Photo detector and preamplifier in one package * Internal filter for PCM frequency * Improved shielding against electrical field disturbance * TTL and CMOS compatibility * Output active low Low power consumption * High immunity against ambient light * Continuous data transmission possible (up to 2400 bps) * Suitable burst length . 10 cycles/burst Block Diagram: Fig. 4. 3 Block Diagram of TSOP 1738 Application Circuit: Fig. 4. 4 Application circuit 4. 3. 3 555 ( TIMER IC): Fig. 4. 5 Timer IC(555) Description: The LM555 is a highly stable device for generating accurate time delays or oscillation. Additional terminals are provided for triggering or resetting if desired. In the time delay mode of operation, the time is precisely controlled by one external resistor and capacitor.
For astable operation as an oscillator, the free running frequency and duty cycle are accurately controlled with two external resistors and one capacitor. The circuit may be triggered and reset on falling waveforms, and the output circuit can source or sink up to 200mA or drive TTL circuits. Features: * Direct replacement for SE555/NE555 * Timing from microseconds through hours * Operates in both astable and monostable modes * Adjustable duty cycle * Output can source or sink 200 mA * Output and supply TTL compatible * Temperature stability better than 0. 05% per °C * Normally on and normally off output * Available in 8-pin MSOP package Applications: * Precision timing * Pulse generation * Sequential timing * Time delay generation * Pulse width modulation * Pulse position modulation * Linear ramp generator 5. 3. 4 LTS 542 (7-Segment Display) Description: The LTS 542 is a 0. 52 inch digit height single digit seven-segment display. This device utilizes Hi-eff. Red LED chips, which are made from GaAsP on GaP substrate, and has a red face and red segment. Fig. 4. 6 7 Segment Features: * Common Anode * 0. 52 Inch Digit Height * Continuous Uniform Segments Low power Requirement * Excellent Characters Appearance * High Brightness ; High Contrast * Wide Viewing Angle 5. 3. 5 LM7805 (Voltage Regulator) Fig. 4. 7 Voltage Regulator Description: The KA78XX/KA78XXA series of three-terminal positive regulator are available in the TO-220/D-PAK package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output current.
Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents. Features: * Output Current up to 1A * Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V * Thermal Overload Protection * Short Circuit Protection * Output Transistor Safe Operating Area Protection 5. 3. 6 RELAY CIRCUIT: Fig. 4. 8 Relay A single pole dabble throw (SPDT) relay is connected to port RB1 of the microcontroller through a driver transistor. The relay requires 12 volts at a current of around 100ma, which cannot provide by the microcontroller.
So the driver transistor is added. The relay is used to operate the external solenoid forming part of a locking device or for operating any other electrical devices. Normally the relay remains off. As soon as pin of the microcontroller goes high, the relay operates. When the relay operates and releases. Diode D2 is the standard diode on a mechanical relay to prevent back EMF from damaging Q3 when the relay releases. LED L2 indicates relay on. CHAPTER :- 5 SOFTWARE DESIGN FLOW CHART: Start Infrared Signal Transmission Interrupted from Sensor1 Interrupted from Sensor 2 Turn On Relay Counter Incremented Counter Decremented
Counter set to 0 Relay Turn Off Turn On Light Turn Off Light Fig. 4. 7 Flow Chart * If the sensor 1 is interrupted first then the microcontroller will look for the sensor 2. And if it is interrupted then the microcontroller will increment the count and switch on the relay, if it is first time interrupted. * If the sensor 2 is interrupted first then the microcontroller will look for the sensor 1. And if it is interrupted then the microcontroller will decrement the count. * When the last person leaves the room then counter goes to 0 and that time the relay will turn off. And light will be turn off. CHAPTER :- 6 TESTING AND RESULTS
Testing And Results We started our project by making power supply. That is easy for me but when we turn toward the main circuit, there are many problems and issues related to it, which we faced, like component selection, which components is better than other and its feature and cost wise a We started our project by making power supply. That is easy for me but when I turn toward the main circuit, there are many problems and issues related to it, which are I faced, like component selection, which components is better than other and its feature and cost wise also, then refer the data books and other materials related to its.
I had issues with better or correct result, which I desired. And also the software problem. I also had some soldering issues which were resolved using continuity checks performed on the hardware. We had issues with better or correct result, which we desired. And also the software problem. We also had some soldering issues which were resolved using continuity checks performed on the hardware. We started testing the circuit from the power supply. There we got over first trouble. After getting 9V from the transformer it was not converted to 5V and the circuit received 9V.
As the solder was shorted IC 7805 got burnt. So we replaced the IC7805. also the circuit part around the IC7805 were completely damaged.. with the help of the solder we made the necessary paths. CHAPTER :- 7 FUTURE EXPANSION FUTURE EXPANSION * By using this circuit and proper power supply we can implement various applications Such as fans, tube lights, etc. * By modifying this circuit and using two relays we can achieve a task of opening and closing the door. CHAPTER :- 8 APPLICATION, ADVANTAGES ; DISADVANTAGES APPLICATION, ADVANTAGES ; DISADVANTAGES Application * For counting purposes * For automatic room light control * Advantages * Low cost * Easy to use * Implement in single door * Disadvantages * It is used only when one single person cuts the rays of the sensor hence it cannot be used when two person cross simultaneously. CHAPTER :- 8 BIBILOGRAPHY Bibliography * Reference Books * Programming in ANSI C: E BALAGURUSAMY * The 8051microcontroller and embedded systems: MUHAMMAD ALI MAZIDI JANICE GILLISPIE MAZIDI * The 8051 microcontroller: KENNETH J. AYALA * Website * www. datasheets4u. com * www. 8051. com