MPX4250AP to PSI for Arduino

mpx4250ap.ino

float getPressure(int raw) {
  // raw 0-1023, get from analogRead();
  // 0.004887585532746823 is from 5v/1023
  // General info:
  // range of voltage reading is 0v-5v
  // the sensor outputs MPV to (MPV + 4.692v), while the range is (0.133v - 0.204v - 0.274v) to (4.826v - 4.896v - 4.966v)
  // each KPa is 20mV or 0.02V
  float voltage = raw * 0.004887585532746823;
  // Typical MPV is 0.204v@20KPa
  // Maximum pressure is 250KPa
  // pressure = voltage * (250 / (MPV + 4.692))
  float pressure = voltage * 51.06209150326797;

  return pressure * 0.145037738; // convert KPa to PSI
}