#include "pots.h"
#include "hardware/adc.h"

#define SAMPLES    16
#define HYSTERESIS 24   /* in 12-bit counts: 0.75 of a 7-bit step past the step's centre */

static int value[2], raw[2];

void pots_init(void){
  adc_init();
  adc_gpio_init(26);   /* also turns off the digital input and pulls */
  adc_gpio_init(27);
  pots_update();
  value[0] = raw[0] >> 5; value[1] = raw[1] >> 5;
}

void pots_update(void){
  int i, k;
  for(i = 0; i < 2; i++){
    int sum = 0, centre, d;
    adc_select_input((uint)i);
    for(k = 0; k < SAMPLES; k++) sum += adc_read();
    raw[i] = sum / SAMPLES;
    centre = value[i] * 32 + 16;
    d = raw[i] - centre;
    if(d > 16 + HYSTERESIS || d < -16 - HYSTERESIS) value[i] = raw[i] >> 5;
  }
}

int pot_value(int pot){ return value[pot]; }
int pot_raw(int pot){ return raw[pot]; }