Compilation error: 'lcdRS' was not declared in this scope?

Projects Programming
1

What's wrong with my code? i'm trying to use the LCD library but it keeps giving me problems


const int trigPin = 9;   // Ultralydsensor trigpin
const int echoPin = 10;  // Ultralydsensor echopin
const int ledPin = 13;   // LED-pin
const int relayPin = 8;  // Rele-pin

#include <LiquidCrystal.h>

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);


void setup() {
  Serial.begin(9600);  // Initialiser seriell kommunikasjon

  pinMode(trigPin, OUTPUT);  // Sett trigPin som output
  pinMode(echoPin, INPUT);   // Sett echoPin som input
  pinMode(ledPin, OUTPUT);   // Sett ledPin som output
  pinMode(relayPin, OUTPUT); // Sett relayPin som output

  // Initialiser LCD-skjerm
  pinMode(lcdRS, OUTPUT);
  pinMode(lcdE, OUTPUT);
  pinMode(lcdD4, OUTPUT);
  pinMode(lcdD5, OUTPUT);
  pinMode(lcdD6, OUTPUT);
  pinMode(lcdD7, OUTPUT);

  lcd.begin(16, 2);
  
}

void loop() {
  // Send en ultralydimpuls
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Mål avstanden til objektet
  long duration = pulseIn(echoPin, HIGH);
  int distance = duration * 0.034 / 2;  // Beregn avstanden i cm

  // Vis avstanden på seriell monitor
  Serial.print("Avstand: ");
  Serial.print(distance);
  Serial.println(" cm");

   // Skriv "HOLD AVSTAND" og avstanden på LCD-skjermen
  lcdWrite("HOLD AVSTAND");
  lcdSetCursor(0, 1);
  lcdPrint(distance);
  lcdPrint(" cm");
  

  // Hvis avstanden er 0,5 meter eller mindre, slå av releen og blink med LEDen
  if (distance <= 50) {
    digitalWrite(relayPin, LOW);
    digitalWrite(ledPin, HIGH);
    delay(250);
    digitalWrite(ledPin, LOW);
    delay(250);
  }
2

Welcome to the forum

The compiler isn't lying. lcsRS is not declared and nor are several other variables

Where did you get the code ?

3

I'm writing it myself, i'm new to arduino. how should i procceed?

4

declare lcdRS as a valid variable.

or use the declared rs const int rs = 12 or change const int rs = 12 to const int lcdRS = 12.

most likely you'll need to declare

pinMode(lcdRS, OUTPUT);
  pinMode(lcdE, OUTPUT);
  pinMode(lcdD4, OUTPUT);
  pinMode(lcdD5, OUTPUT);

and others.

5

Setting the pinModes for the LCD pins is unnecessary. The library takes care of setting up the pins. See the begin() function definition in the LiquidCrystal.cpp file.

6

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