Monitoring The Room And Controlling Its Temperature And Light Intensity From A Remote Location Over A Network

Transcription

1 Copyright, International Journal of Monitoring The Room And Controlling Its Temperature And Light Intensity From A Remote Location Over A Network Parveen K Patra 1, Durga P Tripathi 2 1 Faculty,Roland Institute of Technology, Berhampur, ODISHA 2 Faculty,Roland Institute of Technology, Berhampur, ODISHA patra.praveen@gmail.com,dpt.tara@gmail.com Abstract This paper illustrates the application of monitoring the room and also controlling the temperature and light intensity from a remote place through a web. it is easy to find out whether any person has enter into the room or how many person are present inside the room and depend on the temperature and light intensity of a room we can make a switch off or switch on the light and fan of the room from a remote place. Keywords PIR sensor, RELAY, LDR, Arduino AT Mega 328, LM35 SENSOR, Arduino Ethernet shield. I. INTRODUCTION In this paper, it is well described about the detection of any person entering or leaving the room, determining the room temperature and light Intensity by using some hardware which sends information to the Arduino board. The Arduino board sends the status of the room to the remote user which may take action for controlling the room temperature and light of a room and thus saves the power and energy. shield which contain the W5100 IC which is responsible for sending request and response over the network. This Ethernet shield is controlled by the ATmega328 microcontroller in Arduino Uno. II.HARDWARE PLATFORM A. PIR SENSOR PIR sensor (passive infrared sensor) is an electronic sensor that is used to detect or sense any motion or movement of human being, animal or other object within the range of the sensor. PIR sensor detects the movement by measuring infrared light radiating from the object in its field of view. Its principle of operation is based on that all objects with a temperature above absolute zero emit heat energy in the form of radiation which is not visible to human eye. PIR sensor detects the changes in the amount of infrared radiation impinging upon it due to the object or human being passes in front of it. Change in radiation depends upon the temperature and surface characteristic of the object in front of the PIR sensor. The main algorithm that is implemented is very simple and robust. A motion sensor will sense any movement near the entrance of a room, temperature sensor will sense the temperature of a room and light sensor will sense the light intensity of a room. This sensor will continuously sense and send the information Arduino is basically an open source platform which is very easy to use, and, interfacing with Arduino is simple. The Ethernet Figure. PIR motion sensor The core of the PIR sensor is a solid state sensor or set of sensors made from piezoelectric materials Page 96

2 which generate energy when exposed to heat. Sensors are approximately 40 mm2 and the material commonly used is gallium nitride, caesium nitrate, and polyvinyl fluorides. Its output is in the form of digital pulse (3v) when any motion is detected otherwise the output is digital low. Its sensitivity range is up to 20 feet detection range. B. RELAY Copyright, International Journal of Figure. Relay Relay is one of the most important electromechanical devices highly used in industrial application specifically in automation. Relay are simple switches which are operated both electrically and mechanically. Relay consists of an electromagnet and also set of contacts. It consists of a coil of wire wrapped around a soft iron core, an iron yoke. The switching mechanism is carried out with the help of the electromagnet. A relay generally has 2 parts, a coil which operates at the rated DC voltage and a mechanically movable switch. The electronic and electrical circuit are electrically isolated but magnetically connected to each other, hence any fault on either side does not affect on other side A relay is used where it is necessary to control a circuit by a low power signal or where several circuits must be controlled by one signal. It is generally used for electronic to electrical interfacing i.e. it is used to switch on or off electrical circuits operating at high AC voltage using a low DC control voltage. As shown in the figure, it consists of 5 terminals. Two terminals are used to give the input DC voltage also known as the operating voltage of the relay. Relays are available in different operating voltages like 6V, 12V, 24V etc. The rest of the three terminals are used to connect the high votage AC circuit. The terminals are called common, normally open (NO) and normally closed (NC). C. LIGHT DEPENDENT RESISTOR The sensor that we used in our project is Light Dependant Resistor (LDR).It is made up of Cadmium Selenide (CdS). CdS is mainly used as a pigment. CdS and Cadmium Selenide are used in manufacturing of photo resistor (light de pendent resistors) sensitive to visible and near infrared light. Figure. Internal structure of photo resistor In thin-film form, CdS can be combined with other layers for use in certain types of solar cells. CdS was also one of the first semiconductor materials to be Page 97

3 used for thin film Transistors (TFTs). However interest in compound semi-conductors for TFTs largely waned after the emergence of amorphous silicon technology in the late 1970s. In thin-film form, CdS can be combined with other layers for use in certain types of solar cells. CdS was also one of the first semiconductor materials to be used for thin film Transistors (TFTs). However interest in compound semi-conductors for TFTs largely waned after the emergence of amorphous silicon technology in the late 1970s. It exhibits photoconductivity. It can also be referred as photoconductor. Its resistance decreases with increasing light intensity and vice versa. In bright light its resistance can go down to few ohm.in dark, its resistance goes in the range of mega ohm. Copyright, International Journal of example of an extrinsic semiconductor. Photo resistor is basically photocells. D. Arduino ATmega328 Arduino Atmega328 is used. The image of an Arduino board is shown in Figure 1(a) and the pin diagram is shown in Figure 1(b) which will help to know the detailed hardware configurations of the Arduino board used. Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. Arduino can programmed according to users own need. The power supply can be via USB or external power supply. The power source is selected with a jumper, a small piece of plastic that fits onto two of the three pins between the USB and power jacks. There is sufficient number of pins for To use them as a sensor, we need to measure the voltage drop across the resistor with the analog port of Arduino board ( because a change in resistance means a change in voltage). A photo resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron (and its hole partner) conduct electricity, thereby lowering resistance. A photoelectric device can be either intrinsic or extrinsic. An intrinsic semiconductor has its own charge carriers and is not an efficient semi-conductor, e.g. silicon. In intrinsic devices the only available electrons are in the valence band, and hence the photon must have enough energy to ex-cite the electron across the entire band gap. Extrinsic devices have impurities, also called do pants, and added whose ground state energy is closer to the conduction band; since the electrons do not have as far to jump, lower energy photons (i.e., longer wavelengths and lower frequencies) are sufficient to trigger the device. If a sample of silicon has some of its atoms replaced by phosphorus atoms (impurities), there will be extra electrons available for conduction. This is an (a) (b) Figure (a): Actual Arduino image, Figure (b):rduino pin settings Both analog and digital. Before programming is done on Arduino, the board used has to be selected (AT mega 328) from the tools option of Arduino software. Serial port (COM1/COM2/COM3) in use has to be selected also from the tools menu. The platform is then set for programming. After the desired code is written it has to be uploaded to the microcontroller of the Arduino and then Arduino is expected to work as desired. Page 98

4 Copyright, International Journal of ATmega328 Flash Memory SRAM 32KB; 0.5KB used by boot loader 2KB EEPROM Clock speed Digital I/O pins 1KB 16MHz 14( of which 6 provides PWM output) Analog Input pins 6 Table 1: Specifications for our Arduino E. LM35 Temperature Sensor: LM35 is an integrated circuit sensor that can be used to measure temperature with an electrical output proportional to the temperature (in 0c). The sensor circuitry is sealed and therefore it is not subjected to oxidation and other processes. With LM35 temperature can be measured more accurately than with a thermistor. It also process low self heating and does not cause more than 0.1 0c temperature rise in still air. The operating temperature range is from -550c to 150 0c. The output voltage varies by 10mV in response to every 0c rise/fall in ambient temperature, i.e. its scale factor is 0.01 v/0c. It generates a higher output voltage compared to thermocouple, so output voltage need not be amplified. Figure. LM35 Temperature Sensor These sensors use a solid-state technique to determine the temperature that is to say they don t use mercury like in old thermometers. Instead they use the fact as temperature increases the voltage across a diode increases at a known rate. Pin Function Name No 1 Supply voltage; 5V (+35V to - Vcc 2V) 2 Output voltage (+6V to -1V) Output 3 Ground (0V) Ground This is actually the voltage drop between the base and emitter of a transistor. By precise amplifying the voltage change, it is easy to generate an analog signal that is directly proportional to temperature. As these sensors have no moving parts, they are precise, never wear out, don t need calibration, work under many environmental conditions, and are consistent between sensor and reading. Moreover they are very inexpensive and quite easy to use. F. W5100 Ethernet Shield The arduino Ethernet shield allows you to easily connect your arduino to the internet. This shield enables your arduino to send and receive data from anywhere in the world with an internet connection. You can use it to do fun stuff like control robots remotely from a website, or ring a bell every time you get a new twitter message. This shield opens up endless amounts of possibility by allowing you to connect your project to the internet in no time flat. Page 99

5 Copyright, International Journal of The whole process is divided into many parts. A. Movement Detection Using PIR Sensor In this part, any movement near the entrance is detected. By using PIR motion sensor, whether any person is entering or leaving the room. Figure. Arduino Ethernet Shield Setting it up is simple as plugging the header pins from the shield into your arduino It is based on wiz net W5100 Ethernet chip. The Wiz net W5100 provides a network (IP) stack capable of both TCP and UDP. It support up to four simultaneous socket connection. PIR1 PIR2 ENTRACE The two PIR sensors PIR1 and PIR2 are placed at the opposite end of the entrance. Then some logic is implemented which will count the number of person present into the room Algorithm: 1. Read the time T1 in seconds when PIR1 detects movement. 2. Read the time T2 in seconds when PIR2 detects movement. 3. If T1 > T2 then Counter = Counter Else Counter = Counter Counter value gives number of person present inside the room. B. Temperature Detection Using LM35 Figure. Block Diagram of Arduino Ethernet Shield There is also an onboard micro SD slot which enables you to store a heck-of a lot of data, and serve up entire websites. This requires the use of an external SD library. The board also has space for the addition of a power over Ethernet (PoE) module, which allows you to power your Arduino over an Ethernet connection. III.METHODOLOGY In this part, the temperature of the room is detected by the LM35 temperature sensor and gives the output in analog form. Now microcontroller recieves the signal and send it to the remote user in the form of html over the network. After receiving the temperature of the room the remote user may take some action to control the temperature of the room like SwitchON the FAN if temperature is high or SwitchOFF the FAN if temperature is low. Algorithm: 1. Read the sensor output in the range Convert the output into temperature T1 in Page 100

6 0c. 3. If T1 is High then FAN should be ON. 4. If T1 is Low then FAN should be OFF. C. Light Intensity Measurement Using LDR In this part, the light intensity of a room is measured by using LDR. LDR gives the output in 10 bit resolution. Now microcontroller send the light intensty of the room to the remote user. Now user take some action such as if the light intensity of the room is low the he may SwitchOn the AC Light or if the Light Intensity is High the he may SwitchOFF the AC light. Algorithm: 1. Read the sensor output in range. 2. If light intensity L < 300 the Switch ON the AC light. 3. If L > 900 then Switch OFF the AC light. D. Sending/Receiving Data over Network In this part, the output of all the sensor are send to the remote user over a network using TCP/IP protocol. W5100 IC in arduino ethernet shield responsible for TCP/IP data communication over a network by using request/response method. After getting the response from the user some signal has been send to arduino output pin where the hardware devices are connected to implement the user action. IV. DISCUSSIONS AND CONCLUSION The main aim of this project is to monitor the room from a remote place. If you want to control the Fan and Light of a room from the another location then this project gives the better solution. So by this project we use the AC power according to our requirement so we are saving the power if no one is present inside the room or if any requirement is not there. If you want to monitor the room for any security purpose from a remote place then this project is a better solution. Copyright, International Journal of ield Sensor-Tutorial/ 6. r 7. References Page 101