[attachment=9215]
MOTION DETECTION USING PIR
ABSTRACT
This is a system based on PIR motion detector module. If the motion detection module detects any motion in the room or where it placed, it sends an out put to the micro controller which controls the whole system. When micro controller receives an input from motion detection module, it sends an out put to the relay driver section. When the relay was ON the light became on.
If there is no motion was happened the light remains OFF.
The main sections of this system are:
 PIR MOTION DETECTION MODULE
 Micro controller
 Relay
 Appliance to be controlled.
WORKING
When the PIR motion detection module detects any motion in the room, it sends an out put to the micro controller which controls the whole system. When micro controller receives an input, it sends an out put to the relay driver section. The relay driver section drives the relay ON. When the relay was ON the light became on.
If there is no motion was happened the light remains OFF.
PIR motion detection module
Compact and complete, easy to use Pyroelectric Infrared (PIR) Sensor Module for human body detection. Incorporating Fresnel lens and motion detection circuit. High sensitivity and low noise. Output is a standard 5V active low output signal. Module provides an optimized circuit that will detect motion up to 6 meters away and can be used in burglar alarms and access control systems. Inexpensive and easy to use, it's ideal for alarm systems, motion-activated lighting, holiday props, and robotics applications.
The Output can be connected to microcontroller pin directly to monitor signal or a connected to transistor to drive DC loads like a bell, buzzer, siren, relay, opto-coupler (e.g. PC817, MOC3021), etc. The PIR sensor and Fresnel lens are fitted onto the PCB. This enables the board to be mounted inside a case with the detecting lens protruding outwards.
Features
• Complete with PIR, Motion Detection IC and Fresnel Lens
• Simple 3 connections
• Dual Element Sensor with Low Noise and High Sensitivity
• Supply Voltage: 5V DC
• Standard Active Low Output pin for connecting to microcontroller directly
• Detecting range up to 6 meters
• LED indication
• Module Dimensions: 25mm Length, 32mmWidth, 25mm Height
Applications
• Motion-activated nightlight
• Alarm systems
• Robotics & Holiday animated props
Theory of Operation
Pyroelectric devices, such as the PIR sensor, have elements made of a crystalline material that generates an electric charge when exposed to infrared radiation. The changes in the amount of infrared striking the element change the voltages generated, which are measured by an on-board amplifier. The device contains a special filter called a Fresnel lens, which focuses the infrared signals onto the element. As the ambient infrared signals change rapidly, the on-board amplifier trips the output to indicate motion. The PIR (Passive Infra-Red) Sensor is a pyroelectric device that detects motion by measuring changes in the infrared (heat) levels emitted by surrounding objects. This motion can be detected by checking for a sudden change in the surrounding IR patterns. When motion is detected the PIR sensor outputs a high signal on its output pin. This logic signal can be read by a microcontroller or used to drive a transistor to switch a higher current load.
Warm up time
The PIR Sensor requires a ‘warm-up’ time in order to function properly. This is due to the settling time involved in ‘learning’ its environment. This could be anywhere from 1-2 Minutes. After this warm up time, sensor will be ready to use.
Using the Sensor
• •Connect regulated DC power supply of 5 Volts. Black wire is Ground, Next middle wire is Brown which is output and Red wire is positive supply. These wires are also marked on PCB.
• After powering up, allow startup delay time of 2 minutes before using the sensor. The sensor output might become LOW once or twice during this period since it has to learn about its environment. After 2 minutes, your sensor is ready for use.
• Preset in sensor is for delay time adjustment, Factory setting is 2 seconds. It means when a motion is detected, the sensor will keep output LOW at least for 2 seconds. It is normally not required to adjust this setting. Just in case you need to adjust the delay time, Make note of factory setting position, in case you have to revert back to original setting.
• To test sensor you only need power the sensor by connect two wires +5V and GND. You can leave the output wire as it is. When LED is off the output is at 5V, means no motion detected.
• Walk in front of sensor and the LED will lit up and output becomes 0V. The output is active low and can be given directly to microcontroller for interfacing applications.
Range of Operation
The PIR Sensor has a range of approximately 20 feet(6 meters). This can vary with environmental conditions. The sensor is designed to adjust to slowly changing conditions that would happen normally as the day progresses and the environmental conditions change, but responds by making its output high when sudden changes occur, such as when there is motion.