Arduino UV Meter with 1530 Levels

/*
  * Programmed by : BMIAK Basnayaka
  * Youtube Channel : SetNFix
  * Name : Arduino UV Level Meter with 1530 levels
  * Date : 09th May, 2020
  * email : bmiakbasnayaka@gmail.com
  * Blogspot  :https://setnfix.blogspot.com
  * Website : http://www.setnfix.com
  * Arduino : https://create.arduino.cc/projecthub/SetNFix
  * FaceBook : https://www.facebook.com/setnfix
  * Hackster : https://www.hackster.io/SetNFix
 */


// Pins of 6 LEDs
int led1 = 3;
int led2 = 5;
int led3 = 6;
int led4 = 9;
int led5 = 10;
int led6 = 11;

int ldr = A0;//LDR sensor pin
int sen = A1;//10k Potentiometer

//All the bulbs are off at the beginning
int a=0;
int b=0;
int c=0;
int d=0;
int e=0;
int f=0;


int bright = 0; // Analog level is 0 (LED off 0 -255 on)
int ldrlevel = 0; // Analog read of LDR
int senlevel = 0;// Analog Read of potentiometer



void setup() {
  pinMode(led1,OUTPUT);
  pinMode(led2,OUTPUT);
  pinMode(led3,OUTPUT);
  pinMode(led4,OUTPUT);
  pinMode(led5,OUTPUT);
  pinMode(led6,OUTPUT);
  pinMode(ldr,INPUT);
 pinMode(sen,INPUT);
Serial.begin(9600);
Serial.print("SetNFix Youtube Channel");
 
}

void loop() {

ldrlevel = analogRead(ldr);
senlevel = analogRead(sen);
//delay(100);




bright = map(ldrlevel,senlevel,1023,0,1530);

//if (bright<0) bright =0;
Serial.println(bright);
a = bright;
b = bright - 255;
c = bright - 510;
d = bright - 765;
e = bright - 1020;
f = bright - 1275;

if (a >255) a=255;
if (b >255) b=255;
if (c >255) c=255;
if (d >255) d=255;
if (e >255) e=255;
if (f >255) f=255;


if (a < 0) a=0;
if (b < 0) b=0;
if (c < 0) c=0;
if (d < 0) d=0;
if (e < 0) e=0;
if (f < 0) f=0;


analogWrite(led1,a);
analogWrite(led2,b);
analogWrite(led3,c);
analogWrite(led4,d);
analogWrite(led5,e);
analogWrite(led6,f);


}