Analog Comparitors

Hardware Arduino Due
1

Hello all,

Are there any analogue comparitors available on the Due? The examples online that I find don't seem aplicable to the Due's processor. I am looking through the data sheet, but working examples would be greatly appreciated if people have some!

Thanks,

Wesley.

2

I think DUE's ADC has comparator mode, look in the adc.h and adc.c

void adc_set_comparison_mode(Adc *p_adc, const uint8_t uc_mode);
uint32_t adc_get_comparison_mode(const Adc *p_adc);
void adc_set_comparison_window(Adc *p_adc, const uint16_t us_low_threshold,
                                                                        const uint16_t us_high_threshold);
void adc_set_comparison_channel(Adc *p_adc, const enum adc_channel_num_t channel);

Section 44.7.9 to set interrupt on comparator, bit 26 - COMPE.
44.7.14 - setting EMR register.

Just an example, haven't use comparator yet, but here how you can wrap it up:

void adc_setup ()
{
  pmc_enable_periph_clk(ID_ADC);
//  adc_init(ADC, SystemCoreClock, ADC_FREQ_MAX, ADC_STARTUP_FAST);
  adc_init(ADC, SystemCoreClock, 21000000UL, ADC_STARTUP_FAST);
  NVIC_EnableIRQ (ADC_IRQn);               // enable ADC interrupt vector
  adc_disable_all_channel(ADC);
  adc_enable_interrupt(ADC, ADC_IER_RXBUFF);    <<--- THIS SHOUD BE ADC_IER_COMPE
  adc_set_bias_current(ADC, 0x01); 
  //  adc_enable_tag(ADC);
  adc_enable_channel(ADC, ADC_CHANNEL_7);  // AN0
  adc_enable_channel(ADC, ADC_CHANNEL_6);  // AN1
  adc_enable_channel(ADC, ADC_CHANNEL_5);  // AN2
  adc_enable_channel(ADC, ADC_CHANNEL_4);  // AN3
  adc_start(ADC); 
}

void ADC_Handler (void)
{
  if((adc_get_status(ADC) & ADC_ISR_RXBUFF) ==	ADC_ISR_RXBUFF) {   <<-- AGAIN "COMPE"
    // YOUR ACTION ON EVENT 
   }
}
3

Thanks!

I've been scan reading the data sheet and beggining to recognise a few of the variables you've listed there.

Mighty steep learning curve for a python programmer but looks like the Due will make a cracking stepper driver...