//  File:  wait_for_deadtime.ino
//
//  Structure of salinity control code to implement a deadtime
//  during which no salinity correction is made.  This code is
//  incomplete and will not compile.

unsigned long last_salinity_update;  //  Time of last correction

void setup() {
  Serial.begin(9600);
  last_salinity_update = millis();   //  Initial value; change later
}

void loop() {
  float LCL, UCL, salinity;
  int deadtime = ... ;

  salinity = salinity_reading( ... );
  update_LCD( ... );

  // -- Check for deadtime
  if ( ( millis() – last_salinity_update ) > deadtime ) {

    if ( salinity>UCL ) {
      //  add DI water:  several missing steps
      last_salinity_update = millis();
    }

    if ( salinity<LCL ) {
      //  add salty water:  several missing steps
      last_salinity_update = millis();
    }
  }
}