typedef struct {
  int16_t adc;
  int16_t human;
} kf_t;

const __flash kf_t kf_fuel[] = 
                  {{1024, 0}, {972, 0},{951, 3},{950, 4},{929, 6},
                  {907, 7},{886, 10},{864, 12},{843, 13},{842, 15},
                  {821, 16},{820, 18},{798, 19},{775, 22},{752, 25},
                  {729, 30},{706, 34},{684, 39},{669, 43},{662, 45},
                  {639, 48},{616, 52},{594, 57},{571, 63},{552, 70},
                  {562, 72},{548, 73},{526, 76},{502, 84},{481, 91},
                  {457, 97},{432, 100},{0, 100}};

const __flash kf_t kf_oel_temp[] =
                  {{1024, 150},{976, 150},{962,140}, {942, 130},
                  {930, 125},{917, 120},{889, 110},{858, 100},
                  {826, 90},{794, 80},{762, 70},{728, 60},{695, 50},
                  {662, 40},{628, 30},{611, 25},{594, 20},{560, 10},
                  {527, 0},{0, 0}};

const __flash kf_t kf_h2o_temp[] = 
                  {{1024, 120},{917, 120},{889, 110},{858, 100},
                  {826, 90},{794, 80},{762, 70},{728, 60},{695, 50},
                  {662, 40},{628, 30},{611, 25},{594, 20},{560, 10},
                  {527, 0},{0, 0}};

uint8_t adc2human(int16_t adc, const __flash kf_t* kf) {
  uint8_t min, max, i, j;
  int32_t tmp;

  if (adc < 0) adc = 0;
  if (adc > 1023) adc = 1023;
  min = 1;
  max = 31;
  i = (min+max)/2;

  for (j=0; j < 5; j++) {
    if (kf[i].adc > adc) min = i; else max = i;
    i = (min+max)/2;
  }
  tmp = (adc - kf[i].adc) * (int32_t)(kf[i-1].human - kf[i].human);
  tmp = tmp / (kf[i-1].adc - kf[i].adc) + kf[i].human;
  return tmp;
}

int main(void){
  uint8_t fuel_level;

  fuel_level = adc2human(0, kf_fuel);        // 100
  fuel_level = adc2human(450, kf_fuel);        // 98
  fuel_level = adc2human(960, kf_fuel);        // 2
  fuel_level += adc2human(1023, kf_fuel);      // 0

  uint8_t oel_temp;
  oel_temp = adc2human(0, kf_oel_temp);        // 0
  oel_temp = adc2human(545, kf_oel_temp);      // 5
  oel_temp = adc2human(969, kf_oel_temp);      // 145
  oel_temp += adc2human(1023, kf_oel_temp);      // 150

  uint8_t h2o_temp;
  h2o_temp = adc2human(0, kf_h2o_temp);        // 0
  h2o_temp = adc2human(577, kf_h2o_temp);      // 15
  h2o_temp = adc2human(903, kf_h2o_temp);      // 115
  h2o_temp += adc2human(1023, kf_h2o_temp);      // 120

  while (1){

  }
}