ADC change program

cheng_bei · **Joined:** Sun Dec 27, 2009 1:40 pm **Posts:** 10

My program as below:

Code:

void getbat(void)                            //adc4
{
   unsigned int bat;
   adcinit();
   while(1)
   {
   *AT91C_ADC_CR = AT91C_ADC_START;                      // start ADC conversion      
    while ((*AT91C_ADC_SR & AT91C_ADC_EOC4) == 0);        // wait for ADC conversion  
   bat = (unsigned int) *AT91C_ADC_CDR4 & AT91C_ADC_DATA;   // Read result of ADC conversion
   putchar(bat);
   putchar(bat>>8);

   while ((*AT91C_ADC_SR & AT91C_ADC_EOC6) == 0);        // wait for ADC conversion  
   bat = (unsigned int) *AT91C_ADC_CDR6 & AT91C_ADC_DATA;
    putchar(bat);
   putchar(bat>>8);
   delay(3000000);
   }
}


void adcinit(void)
{
// Setup the A/D converter 

   *AT91C_ADC_CR = AT91C_ADC_SWRST;        // reset ADC                             
   *AT91C_ADC_CHER = AT91C_ADC_CH4 | AT91C_ADC_CH6 ;        // enable ADC channels 0..3              
   *AT91C_ADC_MR = 0x0f1f3f00;            // 10bit,128div,software start  
   *AT91C_ADC_IDR = 0xffffffff;         // Disable adc interrupt
}

cheng_bei · **Joined:** Sun Dec 27, 2009 1:40 pm **Posts:** 10

Now my program can work success. What I need to modify it ,if I want to get a better result???
What I have to pay attention on the software and hardware during the ADC change?? How to select the input resistance,capacitance and so on?? Do I need to judge the flag one by one or I only need to judge the last tunnel ADC_EOC flag (*AT91C_ADC_SR & AT91C_ADC_EOC0,1...7)??? Why I have to read the ADC_CDR not the ADC_LCDR??

:?:

ADC change program

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