Rhythmic Breathing Trainer

float measure() {
/* Read and convert windspeed and temperature from analog inputs of sensor

  This function analog reads the current windspeed and temperature and uses a series of empirically
  derived relationships to convert both windspeed to units of miles per hour and temperature to
  degrees Celsius.

  :returns: float containing windspeed in miles per hour
  :returns: float containing temperature in Celsius
*/

TMP_Therm_ADunits = analogRead(analogPinForTMP);
RV_Wind_ADunits = analogRead(analogPinForRV);
RV_Wind_Volts = (RV_Wind_ADunits*(voltage / bit_depth)); //Converts to voltage

TempCtimes100 =
(0.005*((float)TMP_Therm_ADunits*(float)TMP_Therm_ADunits))-(16.862*(float)TMP_Therm_ADunits)+9075.4;
TempC = TempCtimes100/100.0;
zeroWind_ADunits =
-0.0006*((float)TMP_Therm_ADunits*(float)TMP_Therm_ADunits)+1.0727*(float)TMP_Therm_ADunits+47.172;
zeroWind_volts = (zeroWind_ADunits*0.0048828125)-zeroWindAdjustment;
WindSpeed_MPH =  pow(((RV_Wind_Volts-zeroWind_volts)/.2300),2.7265);
return WindSpeed_MPH, TempC;
}

float calibrate() {
/*
  Measure the ambient temperature and windspeed and the patient's maximum inhale and exhale windspeeds.

  This function is called when the calibration button is pressed on the device. Once the function begins,
  it outputs the wait_code to the Serial monitor, which is interpretted by the computer interface and
  tells the user to "wait." During this waiting period, it measures the ambient temperature and windspeed
  for the delay time specific by ambient_delay. Then, it sends alternating codes for exhale and inhale to
  the Serial monitor, which the user interface interprets, telling the user to breathe out and in as hard
  as possible for the delay time specifed by max_delay. During each of these delays, it measures windspeed,
  doing this 3 times in total and then averaging the values. It the outputs the average ambient temperature
  and windspeed and the maximum inhale and exhale windspeeds.

  :returns: float containing average ambient windspeed
  :returns: float containing average ambient temperature
  :returns: float containing average maximum exhale windspeed
  :returns: float containing average maximum inhale windspeed
*/
flag = 1;
starttime = millis();
Serial.println(wait_code);
while (flag == 1) { //ambient temp/speed calibration
  digitalWrite(calibrate_indicator, HIGH);
  WindSpeed_MPH, TempC = measure();
  temps_total += TempC;
  speed_total += WindSpeed_MPH;
  count += 1;
  nowtime = millis();
  if ((nowtime - starttime) >= (ambient_delay)) {
    avg_temp = temps_total / float(count);
    avg_speed = speed_total / float(count);
    count = 0;
    temps_total = 0;
    flag = 0;
    for (int i = 0; i < 3; i++) {
      Serial.println(exhale_code); //max exhale speed calibration
      delay(max_delay);
      WindSpeed_MPH, TempC = measure();
      max_speed_total += WindSpeed_MPH;
      count_max += 1;

      Serial.println(inhale_code); //max inhale speed calibration
      delay(max_delay);
      WindSpeed_MPH, TempC = measure();
      max_speed_total_in += WindSpeed_MPH;
      count_max_in += 1;

    }
    avg_overall_max_out = max_speed_total / float(count_max);
    avg_overall_max_in = max_speed_total_in / float(count_max_in);
  }
}
Serial.println(calibration_over_code);
digitalWrite(calibrate_indicator, LOW);
return avg_temp, avg_speed, avg_overall_max_out, avg_overall_max_in;
}

int levels(float avg_temp, float avg_speed, float avg_overall_max_out, float avg_overall_max_in) {
/*
  Calculate the level of the patient's breath based on windspeed as compared to average and maximum
  windspeeds

  This function measures the patient's current windspeed and temperature, and then sorts the breaths
  into inhales or exhales. Inhales occur when the temperature of the breath is below the ambient
  temperature, and exhales occur when the temperature of the breath is above the ambient temperature.
  Once the breaths are sorted, the range of each of the five levels is determined by calculating
  the difference between maximum windspeed and ambient windspeed and dividing by the number of levels,
  5. Then, the specific level for the current breath is calculated by dividing the current speed by the
  range previously calculated. If it is an inhale, the level is positive. If it is an exhale, the level
  is negative. If there is no breath (the current windspeed is lower than the ambient speed), the level
  is zero.

  :param avg_temp: float containing the ambient temperature in Celsius
  :param avg_speed: float containing the ambient windspeed in miles per hour
  :param avg_overal_max_out: float containing average maximum exhale windspeed
  :param avg_overal_max_in: float containing average maximum inhale windspeed
  :param num_levels: int containing the total number of levels (usually 5)
*/

float range_in = 1.0;
float range_out = 1.0;

WindSpeed_MPH, TempC = measure();

if (WindSpeed_MPH > avg_speed && TempC <= avg_temp) { //breathing in
  range_in = (avg_overall_max_in - avg_speed) / float(num_levels);
  value = WindSpeed_MPH / range_in;
}
else if (WindSpeed_MPH > avg_speed && TempC >= avg_temp) { //breathing out
  range_out = (avg_overall_max_out - avg_speed) / float(num_levels);
  value = -WindSpeed_MPH / range_out;
}
else if (WindSpeed_MPH < avg_speed) {
  value = 0;
}
return value;
}