Serbian VLF Metal Detector

SURAH-Al-KAHAF-18 by-Mishary-Rashid-Alafasy

My favorite Surah from Quran Kareem

http://quranplay.com/mp3/1062/surah-18-al-kahf-by-mishary-rashid-alafasy.html

Brief history of Surah 

https://www.islamiclandmarks.com/jordan/cave-of-ashabe-kahf-exterior

ARDUINO BASED UNINTERRUPTIBLE DC TO DC POWER SUPPLY

Microcontroller based DC to DC uninterruptible power supply below
Network of ICs 317 & 7805 limited high DC voltages 60 VDC  upto 5 VDC for the whole circuit working.
Here 16*4 LCD used , optocoupler 817 used to derive FET ,48 Vdc Relay used , 

Codes below

  // By Engineer Obaidullah Khan Kakar 28/2/2018
  #include <LiquidCrystal.h>
  #define NUM_SAMPLES 30
  #define DIV_1    58.13465
  #define DIV_2    58.07185
  #define DIV_3    58.0718
  #define DIV_4    58.07185
  #define V_REF    4.991
  LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
  int sum[4] = {0};             
  unsigned char sample_count = 0;
  float voltage[4] = {0.0};     
  char l_cnt = 0;             
  #define led 8
  #define led 9
  #define led 10
  int sensorPin = A2;
  int sensorPin1 = A3;
  int sensorPin2 = A4;
  unsigned int sensorValue = 0;
  unsigned int sensorValue1 = 0;
  unsigned int sensorValue2 = 0;
  void setup(){
  lcd.begin(16, 4); 
  lcd.print("KSF ELECTRONICS");
  delay(700);
  lcd.clear();
  lcd.print("obaidkakar");
  lcd.setCursor(0,1);
  lcd.print(".blogspot.com");
  delay(800);
  lcd.clear();  // clear screen
 pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  Serial.begin(9600);
}
void loop()
{
  while (sample_count < NUM_SAMPLES) {
   for (l_cnt = 0; l_cnt < 4; l_cnt++) {
   sum[l_cnt] += analogRead(A2 + l_cnt); // input were given to lcd
  }
    sample_count++;
    delay(40);
    }
    // calculate the voltage for each channel
    for (l_cnt = 0; l_cnt < 4; l_cnt++) {
        voltage[l_cnt] = ((float)sum[l_cnt] / (float)NUM_SAMPLES * V_REF) / 1024.0;
    }
     lcd.setCursor(0, 0);
    lcd.print("DC1    ");
    lcd.print(voltage[0] * DIV_1, 1); // pin A2
    lcd.print("VDC ");
    lcd.setCursor(0, 1);
    lcd.print("DC2   ");
    lcd.print(voltage[1] * DIV_2, 1); // pin A3
    lcd.print("VDC ");
    lcd.setCursor(0, 2);
    lcd.print("CUTOFF ");
    lcd.print(voltage[2] * DIV_3, 1); //pin A4
    lcd.print("VDC ");
   sample_count = 0;
    for (l_cnt = 0; l_cnt < 4; l_cnt++)
   {
     sum[l_cnt] = 0;
    }
   sensorValue = analogRead( sensorPin);
   sensorValue1 = analogRead( sensorPin1);
   sensorValue2 = analogRead( sensorPin2);
   delay(400);
   if(sensorValue>168) digitalWrite(8, LOW);
   delay(800);
   if(sensorValue>168) digitalWrite(9, HIGH);
   delay(800);
   if(sensorValue<164) digitalWrite(9, LOW);
   delay(800);
   if(sensorValue<164) digitalWrite(8, HIGH);
   delay(400);
   lcd.setCursor(0, 3);
   if(sensorValue>168) lcd.print("DC1 BATT CONECT  ");
   if(sensorValue<164) lcd.print("DC2 BATT CONECT ");
    }