Getting Started

Chapter 9 – Digital Meets Analog – ADC and DAC

once per millisecond

IGNAL(SIG_OUTPUT_COMPARE2)

+)

}

to HyperTerminal

{

for(int i = 0; i < signal; i++)

*********************************************************************************

*******

int dummy = 0;

// Take a dummy reading , which basically allows the ADC

l readings

// Interrupt occurs
S
{
int sig = 0;

sig = ADC_read();

if (tenth >= 10)

{

tenth = 0;

for(int i = 0; i < (sig/4); i+

{

sendChar(' ');

}

sendChar('*');

sendChar('\r');

/* // Test code to ou
if (tenth >= 10)

tput wave from table

tenth = 0;
signal /= 50;

{
sendChar(' ');
}
sendChar('');
sendChar('\r');
signal = 0;
}
/

}

/

• ADC common functions

  ---

  
  

  */

  
  

void ADC_init()
{

ADMUX = 1;

// set ADC prescaler to , 1MHz / 8 = 125kHz
ADCSRA = (1<<ADEN) | (1<<ADPS1) | (1<<ADPS0);

// to hack up any hairballs before we take any rea
dummy = ADC_read();