'microsecondsToCentimeters' was not declared in this scope

[sheshe]

Hello, I tried to run my code in arduino and it keeps telling me that microsecondsToCentimeters’ was not declared in this scope. Though I don’t see any problem with it and I think it should work perfectly. please help me, it already took to much time from me.

This is the code that I tried to run

#include <LiquidCrystal.h>
const int pingPin = 7; // Trigger pin Ultrasonic Sensor 
const int echoPin =6; // Echo pin of Ultrasonic Sensor
const int motorPin =2;
const int puzzer =4;

// initialize the library with the numbers of the interface pins
 LiquidCrystal lcd(13,12,11,10,9,8);

// Then we initialize all the devices used in the project 
 void setup() {
  Serial.begin(9600); //Starting Serial Terminal 
  delay(2000);
  lcd.begin(16,2);
  pinMode(puzzer, OUTPUT);

  pinMode(motorPin, OUTPUT);
  digitalWrite(motorPin, HIGH);
  lcd.setCursor(1,1);
  lcd.print("pump on");
}

void loop() {
  long duration, cm, lev;
  pinMode(pingPin, OUTPUT);
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(pingPin, LOW);

  pinMode(echoPin,INPUT);
  duration = pulseIn(echoPin, HIGH);
  cm = microsecondsToCentimeters(duration);
  lev = 32 - cm;

  lcd.setCursor(1,0);
  lcd.print("level");
  lcd.setCursor(11,0);
  lcd.print("cm");
  lcd.setCursor(10,0);
  lcd.print(" ");
  lcd.setCursor(8,0);
  lcd.print(lev);

  /*After that we check conditions if water level is LOW or water level is HIGH and take
actions accordingly.*/   
  if (lev>28 && lev<32)
  {

     digitalWrite(motorPin, LOW);
     lcd.setCursor(1,1);
     lcd.print("pump off");   
   }
   if (lev>8 && lev<15)
   {
     digitalWrite(puzzer, HIGH);
     delay(500);
     digitalWrite(puzzer, LOW);
     delay(500);
     digitalWrite(puzzer, HIGH);
     delay(500);
     digitalWrite(puzzer, LOW);
     delay(500);

     digitalWrite(motorPin, HIGH);
     delay(500);
     lcd.setCursor(1,1);
     lcd.print("pump on");
     delay(500);
    }
}

[nrobinson2000]

Hey @sheshe,

This forum is for discussion of Particle devices and services. For future Arduino questions you will be better served by the Arduino forum.

---

Regarding your code, you are trying to use a microsecondsToCentimeters function without declaring it. You’re probably looking for the definition provided in the Ping example in the Arduino documentation:

long microsecondsToCentimeters(long microseconds) {
  // The speed of sound is 340 m/s or 29 microseconds per centimeter.
  // The ping travels out and back, so to find the distance of the object we
  // take half of the distance travelled.
  return microseconds / 29 / 2;
}

[sheshe]

Thank you very much, I’ll check the Arduino forum