not enough pressure

Using Arduino Programming Questions
1

Newbie here. I'm setting up an irrigation system using Arduino Uno, relays and three solenoids. I live out in the country and my water pressure is minimal and so I cannot irrigate all three zones at once. When solenoid A is open I need B and C to be closed. Once A is satisfied, then move on to B and close A and C.
Etc. It is probably simple enough but for a retired person with no electronic background, I cannot get my head around it.

I hope I have given you enough information. If not please do not hesitate to ask for more. The code follows.

I thank you in advance.

Pax2

const int sensorValueA = A0; 
const int sensorValueB = A1; 
const int sensorValueC = A2;



const int solenoidA = 13;
const int solenoidB = 12;
const int solenoidC = 11;

void setup() {
Serial.begin(9600);

// read the input on 3 analog pins:
//analogRead(sensorValueA); Serial.println(sensorValueA);
//analogRead(sensorValueB); Serial.println(sensorValueB);
//analogRead(sensorValueC); Serial.println(sensorValueC);

pinMode(solenoidA, OUTPUT);
pinMode(solenoidB, OUTPUT);
pinMode(solenoidC, OUTPUT);
  
}

void loop() {  
  int outputValueA;
  int humidityRealA;
  int outputValueB;
  int humidityRealB;
  int outputValueC;
  int humidityRealC;
  
  outputValueA= analogRead(sensorValueA);
  humidityRealA = map(outputValueA, 1023, 200, 0, 100);
  outputValueB= analogRead(sensorValueB);
  humidityRealB = map(outputValueB, 1023, 250, 0, 100);
  outputValueC= analogRead(sensorValueC);
  humidityRealC = map(outputValueC, 1023, 270, 0, 100);
  
  Serial.print ("Sorsor A  ");
  Serial.print(humidityRealA); 
  Serial.println ("%");
  delay (500); 
   Serial.print ("Sorsor B  ");
  Serial.print(humidityRealB);
   Serial.println ("%"); 
   delay (500); 
   Serial.print ("Sorsor C  ");
  Serial.print(humidityRealC);
   Serial.println ("%"); 
  
  delay(500);

  digitalWrite(solenoidA, LOW);
  digitalWrite(solenoidB, LOW);
  digitalWrite(solenoidC, LOW);
 
   if (humidityRealA < 60)
 {
    digitalWrite(solenoidA, HIGH);
    }
    else if (humidityRealA > 85){ 
    digitalWrite(solenoidA, LOW); }

     if (humidityRealB < 60)
 {
    digitalWrite(solenoidB, HIGH);
    }
    else if (humidityRealB > 85){ 
    digitalWrite(solenoidB, LOW); }

     if (humidityRealC < 60)
 {
    digitalWrite(solenoidC, HIGH);
    }
    else if (humidityRealC > 85){ 
    digitalWrite(solenoidC, LOW); }}

Moderator edit:
</mark> <mark>[code]</mark> <mark>

</mark> <mark>[/code]</mark> <mark>
tags added.

2

Add a variable that can keep track of which zone needs to be done. Every time a zone is humid enough, change to the next zone. I think that the below will work; I've chosen what seem to be sensible values (letters) for the zones.

Not tested but does compile.

void loop()
{
  // keep track of the zone; start with A
  static char zone = 'A';

  int outputValueA;
  int humidityRealA;
  int outputValueB;
  int humidityRealB;
  int outputValueC;
  int humidityRealC;

  outputValueA = analogRead(sensorValueA);
  humidityRealA = map(outputValueA, 1023, 200, 0, 100);
  outputValueB = analogRead(sensorValueB);
  humidityRealB = map(outputValueB, 1023, 250, 0, 100);
  outputValueC = analogRead(sensorValueC);
  humidityRealC = map(outputValueC, 1023, 270, 0, 100);

  Serial.print ("Sorsor A  ");
  Serial.print(humidityRealA);
  Serial.println ("%");
  delay (500);
  Serial.print ("Sorsor B  ");
  Serial.print(humidityRealB);
  Serial.println ("%");
  delay (500);
  Serial.print ("Sorsor C  ");
  Serial.print(humidityRealC);
  Serial.println ("%");

  delay(500);

  digitalWrite(solenoidA, LOW);
  digitalWrite(solenoidB, LOW);
  digitalWrite(solenoidC, LOW);

  if (zone == 'A')
  {
    if (humidityRealA < 60)
    {
      digitalWrite(solenoidA, HIGH);
    }
    else if (humidityRealA > 85)
    {
      digitalWrite(solenoidA, LOW);
      zone = 'B';
    }
  }
  else if (zone == 'B')
  {
    if (humidityRealB < 60)
    {
      digitalWrite(solenoidB, HIGH);
    }
    else if (humidityRealB > 85)
    {
      digitalWrite(solenoidB, LOW);
      zone = 'C';
    }
  }
  else if (zone == 'C')
  {

    if (humidityRealC < 60)
    {
      digitalWrite(solenoidC, HIGH);
    }
    else if (humidityRealC > 85)
    {
      digitalWrite(solenoidC, LOW);
      zone = 'A';
    }
  }
  else
  {
    // invalid zone
  }
}
3

Thank you very much for the reply. The sketch does compile and it does switch zone as intended.