How to Program an Arduino Based Metal Detector

[6666]

Interesting article How to Program an Arduino Based Metal Detector

https://www.instructables.com/id/How-to-Program-an-Arduino-Based-Metal-Detector/

[Teleno]

It's better to use one PWM pin (OCR1A) for driving the MOSFET without servicing any interrupts.

Pages and table references for Atmega328P datasheet at https://www.sparkfun.com/datasheets/.../ATMega328.pdf

/*  Pages and table references for Atmega328P datasheet at    https://www.sparkfun.com/datasheets/Components/SMD/ATMega328.pdf  


    Clock assumed to be 16MHz.                          */


#define F_CPU 1600000L
    
uint sampleDelay = 16 * 10; // 10 us sample delay; 


void init(void) {
  /* Timer 1 in Fast PWM mode 14 (page 136, Table 13-4)  */
  
  TCCR1B |= (1 <<  WGM13) | (1 << WGM12);
  TCCR1A |= (1 << WGM11);
  
  /*  Compare output mode in Fast PWM: 
      set OC1A at BOTTOM (0 count), 
      reset OC1A on compare match. page 135, Table 13-2     */
      
  TCCR1A |= (1 << COM1A1);
  
  /* Compare match registers for  timer 1  */
  
  OCR1A =  4000;               // 250us pulse
  OCR1B =  4000 + sampleDelay; // 16 = 1us
  
  /* The TOP value of timer 1 for Fast PWM 14 is set by the ICR1 register (page 139) */
  
  ICR1 = 16000; // 1ms period, 1000 Hz pulse rate.
  
  /* ADC configured to sample on timer 1 compare match B 
     and generate interrupts on conversion complete */
  
  ADCSRB |=  (1 << ADTS2) | (1 << ADTS0);  // ADC trigger source: compare match B in timer 1
  ADCSRA |=  (1 << ADATE) | (1 <<  ADEN) |  (1 << ADIE); // Autotrigger, enable interrupt, enable ADC
  ADCSRA |=  (1 << ADPS2) | (1 << ADPS1) |  (1 << ADPS0);  // Prescaler 1/128; 125 KHz 
  
  /* Start pulsing */
  
  TCCR1B |= (1 << CS10); // start counter at maximum clock speed
}


int main (void) {
  cli();
  init();
  sei();
  while (1){
    // do your thing
  }
}


ISR(ADC_vect){ 
   // do your thing
} 

[ivconic]

Interesting article How to Program an Arduino Based Metal Detector

https://www.instructables.com/id/How...etal-Detector/

Excellent article!

[Mahally]

Interesting article How to Program an Arduino Based Metal Detector

https://www.instructables.com/id/How...etal-Detector/

That's great! This article is very useful. Thank you

[cristiano.sar]

I built one just for understanding purposes and it's working: https://www.youtube.com/watch?v=LwxB16ynQGs

Thanks!