#define RED_PIN 3
#define GREEN_PIN 4
#define YELLOW_PIN 5
#define PH_RES A0
float yarkost = 2.2;

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);
float procent = valueSensor/yarkost;
if (procent <=30)
digitalWrite(RED_PIN,HIGH);
else
digitalWrite(RED_PIN,LOW);
if (procent >30 && procent <=60)
digitalWrite(GREEN_PIN,HIGH);
else
digitalWrite(GREEN_PIN,LOW);
if (procent >60)
digitalWrite(YELLOW_PIN,HIGH);
else
digitalWrite(YELLOW_PIN,LOW);
delay(300);
}