This document describes the design and implementation of a magnetic door lock system using an Arduino board. The system uses a keypad to enter a secret code, and unlocks a solenoid on the door when the correct code is entered. It provides status using LED lights. The system stores the code in EEPROM and can be programmed to a new code via the keypad. The document outlines the hardware components, circuit diagram, software code, and concludes with potential applications and extensions of the system.

1. A Magnetic Door Lock employing Arduino
Technology
BY,
SRAVANTHI RANI SINHA S

2. A Magnetic Door Lock employing Arduino
Technology
• To sense the correctness of a secret code
using the Arduino technology.
• When the correct code is entered through
keypad, it lights a green LED in addition to
operating a small solenoid.

3. 1. Arduino Introduction
2. Variety and Shields and Sensors
3. Applications
4. Design and Development of Magnetic DOOR
lock

4. Arduino is a board
USB to Serial Digital In/Out Pins
USB Port
Atmega328p
Power Supply
Power Pins Analog Input Pins

5. Hardware Features
Microcontroller ATmega168/ATmega328
Operating Voltage 5V
Microcontroller ATmega168
Input Voltage (recommended)
Operating Voltage 5V 7-12V
Input Voltage (limits) 7-12V
Input Voltage (recommended)
Input Voltage (limits) 6-20V
6-20V
DigitalI/O Pins
Digital I/O Pins 14 (of which 6 provide PWM(of which 6 provide PWM output)
14 output)
Analog Input Pins 6
Analog Input Pins
DC Current per I/O Pin 40 mA 6
DC Current per Pin Pin 50 mA
DC Current for 3.3V
I/O 40 mA
16 KB (ATmega168) or 32 KB (ATmega328) of which 2 KB used by
Flash Memory
DC Current for 3.3V Pin bootloader 50 mA
SRAM 1 KB (ATmega168) or 2 KB (ATmega328)
EEPROM 512 bytes (ATmega168) or 116 (ATmega328)
KB KB (ATmega168) or 32 KB
Flash Speed
Clock Memory 16 MHz (ATmega328) of which 2 KB used by
bootloader
1 KB (ATmega168) or 2 KB
SRAM
(ATmega328)
512 bytes (ATmega168) or 1 KB
EEPROM
(ATmega328)
Clock Speed 16 MHz

6. BLOCK DIAGRAM OF ATMEGA MICROCONTROLLER

7. ATMEGA168 MICROCONTROLLER
Its features includes:
• 23 general purpose I/O lines
• 32 general purpose working registers
• 3 flexible timer/counters with compare/capture/PWM mode, a SPI
serial port
• 16K bytes of in-system programmable Flash with Read-while-Write
capabilities.
• 512 bytes of EEPROM and 1K bytes SRAM.
• In Idle mode CPU stops working while allowing the SRAM,
timers/counters, USART, SPI port and interrupt system to continue
functioning.
• It also has 6 channel 10-bit ADC, a programmable watchdog timer
with internal oscillator .

11. 2. Arduino Variety, Shields and Sensors

12. Arduino Variety

13. Arduino Shield
Add-on module to extend arduino’s
capabilities. Also called Daughterboard
or Cape

14. Shields

15. Communication Shields
Ethernet WiFi RFID
GPS
Bluetooth GPRS

16. Sensors
IR Thermometer Smoke Detector Pressure
Polar Heart Rate Sensor RTC pH Sensor

17. 3. Applications

18. Heart Rate Monitor Interface

19. Arduino Electric Blinds
http://bitly.com/zfZT3H
Gear Motor

20. Barcode scanner

21. Lego and Arduino
http://bitly.com/wLBvY0
NXShield

22. Design and Development of
Magnetic Door lock
COMPONENTS AND EQUIPMENT
• Arduino Diecimila or
Duemilanove board or clone
• D1 Red 5-mm LED
• D2 Green 5-mm LED
• R1-3 270 resistor
• K1 4 x 3 keypad
• 0.1-inch header strip
• T1 BC548
• 5V solenoid (< 100 mA)
• D3 1N4004

23. The schematic diagram

24. The Bread Board Layout

25. The software for this project
#include <Keypad.h> void loop()
#include <EEPROM.h> {
char* secretCode = "1234"; char key = keypad.getKey();
int position = 0; if (key == '*' && ! Locked)
boolean locked = true; {
const byte rows = 4; // unlocked and * pressed so change code
const byte cols = 3; position = 0;
char keys[rows][cols] = getNewCode();
{{'1','2','3'},{'4','5','6'},{'7','8','9'},{'*','0','#'}}; updateOutputs();
byte rowPins[rows] = {2, 7, 6, 4}; }
byte colPins[cols] = {3, 1, 5}; if (key == '#‘){
Keypad keypad = Keypad(makeKeymap(keys), rowPins, locked = true;
colPins, rows, cols); position = 0;
int redPin = 9; updateOutputs(); }
int greenPin = 8; if (key == secretCode[position]){position ++;}
int solenoidPin = 10; if (position == 4)
void setup() { {
pinMode(redPin, OUTPUT); locked = false;
pinMode(greenPin, OUTPUT); updateOutputs();
loadCode(); }
flash(); delay(100);
updateOutputs(); } }

26. void updateOutputs() void loadCode()
{ {
if (locked){ if (EEPROM.read(0) == 1){
digitalWrite(redPin, HIGH); secretCode[0] = EEPROM.read(1);
digitalWrite(greenPin, LOW); secretCode[1] = EEPROM.read(2);
digitalWrite(solenoidPin, HIGH);} secretCode[2] = EEPROM.read(3);
else{ secretCode[3] = EEPROM.read(4);}
digitalWrite(redPin, LOW); }
digitalWrite(greenPin, HIGH); void saveCode()
digitalWrite(solenoidPin, LOW);} {
} EEPROM.write(1, secretCode[0]);
EEPROM.write(2, secretCode[1]);
void getNewCode(){ EEPROM.write(3, secretCode[2]);
flash(); EEPROM.write(4, secretCode[3]);
for (int i = 0; i < 4; i++ ) EEPROM.write(0, 1);
{ }
char key; void flash()
key = keypad.getKey(); {
while (key == 0){key = keypad.getKey();} digitalWrite(redPin, HIGH);
flash(); digitalWrite(greenPin, HIGH);
secretCode[i] = key; delay(500);
} digitalWrite(redPin, LOW);
saveCode();flash();flash(); digitalWrite(greenPin, LOW);
} }

27. Putting It All Together

28. Conclusion and future scope
• A Magnetic Door Lock employing Arduino
technology is presented. we have
implemented a fail safe maglock ,fail secure
maglock also can be implemented.
• Instead of keypad Reader using the variety of
sensors and shields various combinations of
Magnetic Door Lock can be produced and
installed according to the requirements of any
Industry.

29. References
• http://arduino.cc/
• ITP Physical Computing
• http://www.ladyada.net
• http://www.sparkfun.com
• http://www.openlabtaipei.org/ (Openlab Taipei)
• http://seeedstudio.com
• http://coopermaa2nd.blogspot.com
Thank you,
Sravanthi Rani Sinha s
(09BD1A04A0)