int PR1_OUT = 0; // PA4
int PR1_IN = 1; // PA5
int PR2_OUT = 2; // PA6
int PR2_IN = 3; // PA7
int PR3_OUT = 4; // PB5
int PR3_IN = 5; // PB4
int SOL_OUT = 10; // PC0

void setup() {
  Serial.begin(9600);
  pinMode(PR1_OUT, OUTPUT);
  pinMode(PR2_OUT, OUTPUT);
  pinMode(PR3_OUT, OUTPUT);
  pinMode(PR1_IN, INPUT);
  pinMode(PR2_IN, INPUT);
  pinMode(PR3_IN, INPUT);
  pinMode(SOL_OUT, OUTPUT);
}

void loop() {
  digitalWrite(PR1_OUT, HIGH);
  int valPR1 = analogRead(PR1_IN);
  digitalWrite(PR2_OUT, HIGH);
  int valPR2 = analogRead(PR2_IN);
  digitalWrite(PR3_OUT, HIGH);
  int valPR3 = analogRead(PR3_IN);
  Serial.print(valPR1);
  Serial.print(",");
  Serial.print(valPR2);
  Serial.print(",");
  Serial.println(valPR3);

  if (valPR1 < 870 || valPR2 < 870 || valPR3 < 870 ) {
    delay(300);
    digitalWrite(SOL_OUT, HIGH);
    delay(100);
    digitalWrite(SOL_OUT, LOW);
    delay(100);
    digitalWrite(SOL_OUT, HIGH);
    delay(100);
    digitalWrite(SOL_OUT, LOW);
    delay(100);
    digitalWrite(SOL_OUT, HIGH);
    delay(100);
    digitalWrite(SOL_OUT, LOW);
    delay(100);
  }
  delay(10);
}