Getting Started

Chapter 7: Microcontroller Interrupts and Timers

ctc[j++] =
}
else

return 0;
}
}

ctc[j] = '\0';

if(j>4)// must be < 256
{
sendString("Error - Parse_ctc number too large");
return 0;
}
else
{
set_ctc(atoi(ctc));
}

1;

oid set_ctc(int count)
{
char ctc[11];

sendString("Setting the Compare Timer Count to: ");
itoa(count,ctc,10);
sendString(ctc);
sendChar('\r');

MilliSec_init(count);

}

/*
The USART init set the system oscillator to 2 mHz. We set the Timer0

ompare of 250 throws an interrupt every millisecond.

s[i++];

{
sendString("Error - Parse_ctc received a non integer: ");
sendChar(s[i]);
sendChar('\r');

return
}

v

prescaler to clk/8 which gives a 250 kHz input to the timer/counter. A
c
*/
void MilliSec_init(unsigned char count)
{
// Initialize Timer0.

// Enable timer0 compare interrupt
TIMSK0 = (1<<OCIE0A);