IEEE/OSA/IAPR International Conference on Informatics, Electronics & Vision

Sustainable Powered Microcontroller-Based Intelligent Security System for Local and Remote Area Applications Taslim Ahmed1*, Sheik Md. Kazi Nazrul Islam1, Imran Chowdhury1,2, Shuza Binzaid3 1

University of Information Technology and Sciences (UITS), Dhaka 1212, Bangladesh 2 Convenient Energy Solution (CoEn), Dhaka, Bangladesh 3 University of Texas at San Antonio, Texas 78249, USA * [email protected]

Abstract—Microcontrollers and their ever growing applications have changed our everyday experience by its feature of programmability, data processing speed and with the consequent intelligences. Through this adventure of invention and engineering, the optoelectronic devices especially the light emitting diodes (LEDs) are used in various fields, such as electronic appliances, optical communication, security, navigation, agro-electronics, etc. To implement these scopes, the LEDs are required to be controlled with a higher degree of precision and flexibility, which is the concern of this work. Towards that various control of a bi-color LED is implemented with a built in alarm system and a liquid crystal display (LCD) for information display; which are automatically controlled by the microcontroller Atmega8. A Light Dependent Resistor (LDR) and a variable resistor (VAR/POT) is used to provide individual input data for comparison, and produces a pre-programmed output to operate the bi-color LED such as LED ON/OFF, LED blinking, LED color changing and alarming. The developed system of a single bi-color LED (0.1-watt) required 0.98µA and 23.5mA current, and 4.88mW and 117.5mW power, during standby and automated blinking sequences (Yellow-Off-Red) respectively; and the buzzer consumed only 0.49mW power for alarming keeping the supply voltage level of 5V. These very low power consumptions and level of power supply voltage lead it to be very compatible with solar power system, and also applicable in local and remote security application. Proteus ISIS 7.7 is used for system design and simulation by which it is proved to be applicable for security purpose. Code Vision AVR is used to write the program code and for burning the microcontroller ATmega8.

I. INTRODUCTION The application of microcontroller based devices are continuing to rise with its greater processing speed and flexible control; and the electrical appliances are getting more miniaturized, less costly and low power consuming. Microcontrollers reduces the number of chips and the amount of wiring and circuit board space, that would be needed to produce equivalent systems using separate chips or discrete elements. Furthermore, each pin of a microcontroller interfaces several internal peripherals, with the pin function selected by software. This allows a wider variety of applications than single specific functions. The world of microchip and microcontroller has left the human races wondering with its incredible intelligence and control, in numerous applications such as cellular phone, automobile engine, control system, remote controls, office machines appliances, programmable interval timer, power tools and toys and analog to digital or digital to analog converters, etc. Thus, this programmable device (microcontroller) provides a unique tool to interface the ‘Nature and Device’, to add a Hi-Tech dimension in the fashion of our everyday life. This phenomenal aspect of opportunity led our thoughts to a vision of interfacing the Light (nature) and the LED (device). To interface the light, an LDR is used which has a negative coefficient of resistance and this property is utilized for the intelligent control of an LED, correspond to a time varying light intensity. But to design a system with artificial intelligence with higher data processing rate, small size, low power consuming and most importantly cost efficient; is always a prior goal for system designers. And in this challenge, microchip or microcontrollers are able to deliver powerful features that would otherwise be impossible, or too costly to implement. LEDs are gaining more and more popularity for their use in many applications and appliances, due to

276

their relative low power consumption, low cost, size, durability, wide operating range and controllable intensity of illumination. Microcontroller based system makes an LED lamp programmable and intelligent. The advanced features of the Microcontroller ATmega8, provides a flexible control of LED operation with an aspect of higher precision, which is very complex to achieve with some discrete component electronics. More on the accuracy and lower power consumption makes the microcontroller based LED system more efficient, regarding operation control and energy management. Through these inspirations, a bi-color LED controller is an ambition for optical signaling, communication and agro-electronics. Some works been done on this interest and their contributions left a lot of scope to meet. This project work implements this vision of designing and controlling an LED’s ON/OFF state and its illumination pattern (blinking and color changing) according to the change in light intensity; using microcontroller ATmega8. The turning ON operation state, of LED is annotated with a Buzzer by alarming sound. More on an LCD is interfaced to display the information related to light intensity. II. FLOORPLAN & MATERIAL Before proceeding to the precise technical aspects, the required components should be mentioned, also the frame to get the desired behavior from the system. As mentioned before, to control the operation of a bi-color LED intelligently in sense of interpretation of discontinuity in incident light on a particular location for, a microcontroller based system is designed and constructed; where the components (in Table 1) are directly or indirectly interfaced with the microcontroller to retrieve inputs data and drive outputs according to the instructions assigned inside the program code of microcontroller ATmega8.

ICIEV 2012

IEEE/OSA/IAPR International Conference on Informatics, Electronics & Vision Table 1. Components of the system.

Components Resistor Capacitor Integrated Circuit Transistors

Reference R1, R2,R3, R4, R5,R6,R7, POT/VAR C1,C2

330Ω, 10kΩ, 330Ω, 330Ω, 1kΩ, 100Ω, 100Ω, 10kΩ

U1, U2

Atmega8,7805

Q1,Q2,Q3

BC337 (3) 1N4007 (4), LED-Yellow (1), LED-red (1) LCD LM016L, transformer (220V ac to 12V dc)

Diodes

D1-D7

Miscellaneous

LCD, Transformer, LDR, Buzzer

Value

1000uF, 220uF

The flowchart in Fig. 1 describes the logic flow of the sensor and controlling system which is set basically on the SET Voltage (SV) for the reference, where the buzzer and LED will operate accordingly with the changing Real Time Voltage (RTV). The pattern of LED controlling is designed in this way because of ensuring the high scope of precision. This pattern can be modified with the requirements of the local systems. Also other supporting features can be interfaced to it; in fact a display is interfaced to it to show the percentage of voltage across the SV POT, and the LDR.

Fig. 1: Basic logic flowchart of the system.

The block diagram in Fig. 2 depicts the overall concepts of the sensor and control system along with the power management blocks, where double grid

277

power supply can be used by a grid control unit. It facilitates the system be powered up even when the commercial power supply is not available, which makes it sustainable.

Fig. 2: The system block diagram of the intelligent light sensor using microcontroller.

III. CIRCUIT DESIGN & CODING In case of software based design and simulation, a power supplier is constructed to establish a dc voltage of +5V (in Fig. 3), to provide necessary biasing of microcontroller ATmega8 (in the center of Fig. 3) and other circuitry. A bi-color LED is connected with the +5V terminal. A light dependent resistor (LDR) and a series resistor as a voltage divider are connected with the rectifier output voltage (+5V) and the divided voltage is interfaced with the ADC (4) of ATmega8. A buzzer is grounded with a series npn transistor and the transistor drived with the interfaced port PB1 (pin no.2 of Port B). A VAR/POT is connected to the +5V and the ADC (3) of ATmega8. One input obtained from the VAR/POT through ADC (3) is read by ATmega8 as the “SET Voltage (SV)”. Another voltage obtained across the R2 through ADC (4) is varied by the change in intensity of light – is read by ATmega8 as the “Real Time Voltage (RTV)”. When the incident lights on the LDR increases, the resistance of the LDR decreases and the voltage across the series resistance R2 increases. Thus the value of the RTV increases and when the incident light on the LDR decreases. But when the incident lights on the LDR decreases the resistance of the LDR increases and the voltage across the series resistance R2 decreases. Thus the value of the RTV decreases. A bi-color LED (yellow and red) with series resistor R6, R7 – is connected as load or lamp which is drived by the microcontroller ATmega8 through the port ADC (2) and ADC (1) and a liquid crystal display (LCD) is connected with the Port D of ATmega8. The schematic of the system is shown in Fig. 3. To make a microcontroller based system artificially intelligent, a set of program code must be written and burn into the microcontroller. This program code consists of a set of organized instructions or commands, which is followed by microcontroller. Regarding this method of creating artificial intelligence, ‘Code Vision

ICIEV 2012

IEEE/OSA/IAPR International Conference on Informatics, Electronics & Vision AVR version 2.05.0 Professional’ is used to write and burn codes shown in Table 2.

Fig. 4: RTV (51%) > SV (50%); LED is OFF in step 1.

Fig. 3: Schematic of an LED based intelligent light sensor using microcontroller.

There were some other set of codes needed those were generated by Code Vision AVR itself automatically. The codes are written in the exact way followed by the flowchart in Fig. 1 Table 2: Program primary codes for the designed system.

while (1) { adc=read_adc(4)/10; lcd_clear(); lcd_gotoxy(0,0); lcd_putsf("UITS Int. LAMP "); sprintf(lcd,"LDR Voltage=%d%c",adc,37); lcd_gotoxy(0,1); lcd_puts(lcd); delay_ms(500); if(adc>=(read_adc(3)/10)) {PORTB.1=0;PORTC.1=0;PORTC.2=0;m=0;} if(adc