Arduino nano metal detector project by Mirko Pavleski

Code:
// PI metal detector for arduino version_18_min (C) alex --- 1967 2015

int ss0 = 0;

int ss1 = 0;

int ss2 = 0;

long c0 = 0;

long c1 = 0;

long c2 = 0;

byte i = 0;

int sss0 = 0;

int sss1 = 0;

int sss2 = 0;

int s0 = 0;

int s1 = 0;

int s2 = 0;





void setup ()

{

DDRB = 0xFF; // port B - all out

DDRD = 0xFF; // port D - all out



for (i = 0; i <255; i ++) // calibration / calibration

{

PORTB = B11111111; // translate the pins of port B to 1, thus opening. key (turn on)

delayMicroseconds (200); // wait 200 microseconds

PORTB = 0; //

delayMicroseconds (20);

s0 = analogRead (A0);

s1 = analogRead (A0);

s2 = analogRead (A0);

c0 = c0 + s0;

c1 = c1 + s1;

c2 = c2 + s2;





delay (3);

}

c0 = c0 / 255;

c0 = c0 - 5;

c1 = c1 / 255;

c1 = c1 - 5;

c2 = c2 / 255;

c2 = c2 - 5;





}



void loop ()

{

PORTB = B11111111; // translate the pins of port B to 1, thus opening. key (turn on)

delayMicroseconds (200); // wait 200 microseconds

PORTB = 0; // close the key by interrupting the current in the search coil (turn off - interrupt circut in search coil)

delayMicroseconds (20);

s0 = analogRead (A0);

s1 = analogRead (A0);

s2 = analogRead (A0);

ss0 = s0 - c0;



if (ss0 <0)

{

sss0 = 1;

}

ss0 = ss0 / 16;

PORTD = ss0; // send to the indicator (send to LEDs)

delay (1);



ss1 = s1 - c1;

if (ss1 <0)

{

sss1 = 1;

}

ss1 = ss1 / 16;

PORTD = ss1; // send to the indicator (send to LEDs)

delay (1);





ss2 = s2 - c2;

if (ss2 <0)

{

sss2 = 1;

}

ss2 = ss2 / 16;

PORTD = ss2; // send to the indicator (send to LEDs)

delay (1);



if (sss0 + sss1 + sss2> 2)

{

digitalWrite (7, HIGH);

digitalWrite (6, HIGH);

digitalWrite (5, HIGH);

digitalWrite (4, HIGH);

digitalWrite (3, HIGH);

digitalWrite (2, HIGH);

digitalWrite (1, HIGH);

digitalWrite (0, HIGH);

delay (1);

sss0 = 0;

sss1 = 0;

sss2 = 0;

}

}