#define RED_PIN 3
#define GREEN_PIN 4
#define YELLOW_PIN 5
#define PH_RES A0

void setup() {
Serial.begin(9600);
pinMode(RED_PIN,OUTPUT);
pinMode(GREEN_PIN,OUTPUT);
pinMode(YELLOW_PIN,OUTPUT);
pinMode(PH_RES, INPUT);
}

void loop() {
int valueSensor = analogRead(PH_RES);
Serial.print("yrov. osv=  ");
Serial.println(valueSensor);
if (valueSensor>=35 && valueSensor <=45)
digitalWrite(RED_PIN,HIGH);
else
digitalWrite(RED_PIN,LOW);
if (valueSensor >=215 && valueSensor<= 230)
digitalWrite(GREEN_PIN,HIGH);
else
digitalWrite(GREEN_PIN,LOW);
if (valueSensor>=112 && valueSensor<=210)
digitalWrite(YELLOW_PIN,HIGH);
else
digitalWrite(YELLOW_PIN,LOW);
delay(300);
}