Trying to show my light as a percentage

Projects General Guidance
1

Hi everybody so I have this project I am working on it is a ventilator

so far so good but for example I do not have like a O2 tank so I am going to simulate it with a led and for that idea I have this simple sketch about increasing and decreasing the LED light with 2 buttons

int button1 = 4;
int button2 = 3;
int buttonVal1;
int buttonVal2;
int LEDbright = 0;
int led = 8;
int buzz = 13;


void setup() { // put your setup code here, to run once:
  pinMode(button1, INPUT_PULLUP);
  pinMode(button2, INPUT_PULLUP);
  pinMode(led, OUTPUT);
  pinMode(buzz, OUTPUT);
  Serial.begin(9600);
}

void loop() { // put your main code here, to run repeatedly:
  buttonVal1 = digitalRead(button1);
  buttonVal2 = digitalRead(button2);
  Serial.print("button 1 = ");
  Serial.print(buttonVal1);
  Serial.print(", ");
  Serial.print("button 2 = ");
  Serial.println(buttonVal2);
  delay(250);

  if (buttonVal1 == 0){
    LEDbright = LEDbright + 5;
  }
  if (buttonVal2 == 0){
    LEDbright = LEDbright - 5;
  }
  if (LEDbright > 255){
    LEDbright = 255;
    digitalWrite(buzz, HIGH);
    delay(100);
    digitalWrite(buzz, LOW);
  }
  if (LEDbright < 0){
    LEDbright = 0;
    digitalWrite(buzz, HIGH);
    delay(100);
    digitalWrite(buzz, LOW);
  }


  analogWrite(led, LEDbright);
}

What I want is once I connect my LCD I want that when the LED is completely turned off for it to be equal to 21% and as I gradually increase brightness for it to go up to 100%

so im not sure how to do the math for this to work if anybody has any tips thanks.

2

The eye's response to brightness is not a simple linear relationship.

You'd be better displaying the percentage on a text display (think: serial monitor), or a bar graph.

3

Yeah I am going to display the percentage on my display

But for example in my sketch I start at 0 and end in 255 by increasing 5 at a time

All I want is to display those values of 0 to 255 as a percentage from 21% to 100%

Because the brightness of the LED is just for show but the display will show percentage depending on the LED

4

Have you tried the map function?

5

Never used map functions and don't know waht they are but just did a quick googled search and I think that will work thanks a lot @TheMemberFormerlyKnownAsAWOL

6

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