"display was not declared on this scope" while using oled display

Using Arduino Programming Questions
1

Hello,

I am new here. I am working on an automated sprinkler system using ds3231. I chose to use an oled display as the display. but when I try to upload it, there is an error message always.
this is my code,

#include "DS3231lib.h"
#include "Wire.h"
#include "Adafruit_GFX.h"
#include "Adafruit_SSD1306.h"
#include "SPI.h"

int Relay = 4;

DS3231lib rtc(SDA, SCL);
Time t;

const int OnHour1 = 06;
const int OnMin1 = 00;
const int OnHour2 = 18;
const int OnMin2 =00;
const int OffHour1 = 06;
const int OffMin1 = 15;
const int OffHour2 = 18;
const int OffMin2 = 15;

void setup() {
Serial.begin(115200);
rtc.begin();
pinMode(Relay, OUTPUT);
digitalWrite(1,OUTPUT);
digitalWrite(Relay, LOW);
SPI.begin();
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.clearDisplay();
display.display();
testscrolltext();
display.clearDisplay();
display.display();
}

void loop() {
t = rtc.getTime();
display.display(); // this is the error line
display.clearDisplay();
display.setTextColor(WHITE);
display.setTextSize(2);
display.setCursor(20,0);
display.print(" hour - ");
display.print(t.hour);
display.println(" minute - ");
display.print(t.min);
delay (5000);
display.clearDisplay();
display.display();

if(t.hour == OnHour1 && t.min == OnMin1){
digitalWrite(Relay,HIGH);
Serial.println("Sprinkler turning on");
}

else if(t.hour == OffHour1 && t.min == OffMin1){
digitalWrite(Relay,LOW);
Serial.println("Sprinkler turning off");
}
if (t.hour == OnHour2 && t.min == OnMin2 ){
digitalWrite(Relay, HIGH);
Serial.println("Sprinkler turning on");

}
else if (t.hour == OffHour2 && t.min == OffMin2){
digitalWrite(Relay, LOW);
Serial.println("Sprinkler turning off");
}

}

The error message is 'display' was not declared on this scope.

please help me

2

Hi Anasura,

imagine you want to order a pizza just saying "I want a pizza"

You will be asked back some questions:

  • where do you want to eat the pizza restaurant or at home?
  • what should be on the pizza?
  • what size shall the pizza have?

Now a pizza is a much lesser complex thing than an Arduino.
This means you have to provide more information to get help
This is the reason why there is a sticky post at the top of the forum
so please read it it.

How to get the best out of this forum

best regards Stefan

3

The error message is 'display' was not declared on this scope.

So where is display declared ?

If you look at

DS3231lib  rtc(SDA, SCL);

you will see an instance of the DS3231 library named rtc being created for use later in the sketch

Where is the equivalent instantiation of the display object ?

4

anusara2006:
The error message is 'display' was not declared on this scope.

please help me

Indeed. Furthermore, display is not declared at all.

5

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.