Hey,
As an assignment at college me and some friends are working together to build an Arduino powered Locking and alarm system with a keypad for interfacing. This is my first Arduino project so I thought I'd post our progress on here.
Today I finished programming the prototype keypad system as seen in the image bellow.
We are using:
An Arduino Duemilanova
A Matrix keypad with 4 5.6 Kohm resistors on the rows.
2 Ultrabright 5v LEDs (Green and Red) to indicate locked/unlocked status.
The code I wrote is as follows.
#include <Keypad.h>
const byte rows = 4;
const byte cols = 3;
int red = 12;
int green = 11;
char keys[rows][cols] =
{
{'1','2','3'},
{'4','5','6'},
{'7','8','9'},
{'*','0','#'}
};
byte rowPins[rows] = {5, 4, 3, 2};
byte colPins[cols] = {8, 7, 6};
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, rows, cols );
void setup()
{
Serial.begin(9600);
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
}
void loop()
{
char key1;
char key2;
char key3;
char key4;
digitalWrite(red,HIGH);
digitalWrite(green,LOW);
do
{
key1 = keypad.getKey();
if(key1 != NO_KEY)
{
if(key1 == '*')
{
asm volatile ("jmp 0x0000");
}
do
{
key2 = keypad.getKey();
if(key2 != NO_KEY)
{
if(key2 == '*')
{
asm volatile ("jmp 0x0000");
}
do
{
key3 = keypad.getKey();
if(key3 != NO_KEY)
{
if(key3 == '*')
{
asm volatile ("jmp 0x0000");
}
do
{
key4 = keypad.getKey();
if(key4 == '*')
{
asm volatile ("jmp 0x0000");
}
} while (key4 == NO_KEY);
}
} while (key3 == NO_KEY);
}
} while (key2 == NO_KEY);
}
}while (key1 == NO_KEY);
if(key1 == '1' && key2 == '3' && key3 == '3' && key4 == '7')
{
digitalWrite(red,LOW);
digitalWrite(green,HIGH);
delay(3000);
}
}
In summary this code expects the 4 digit key "1337" and changes the states of the LEDs acordingly. I then used
if(keyX == '*')
{
asm volatile ("jmp 0x0000");
}
as a method of using the asterix key to clear the pressed keys, it simply jumps to the 1st instruction.
Upcoming additions:
An alarm system that would sound if the internal sensors are tripped.
Possibly using ultra-sound or light sensors with a laser.
We will be fashioning an enclosure for the keypad that will allow the Arduino to simply slot in as if it were a CPU socket.
Any suggestions are welcome and so are any queries.
Daniel Taylor