// https://forum.arduino.cc/t/help-needed-on-quick-flash-happening-during-led-chase-sequence/1206800/8

//this code is create an LED Chaser using 12 LEDs: three blue, 3 green, three yellow, and three white
//the wiring runs from Nano I/O pin to resistor; resistor is connected to LED anode; LED cathode is connected to ground
int bLED1 = 2;
int bLED2 = 3;
int bLED3 = 4;
int gLED1 = 5;
int gLED2 = 6;
int gLED3 = 7;
int yLED1 = 8;
int yLED2 = 9;
int yLED3 = 10;
int wLED1 = 11;
int wLED2 = 12;
int wLED3 = 13;
int dT = 100;  //delay time
int dTchase;   //delay time variable for chase function

void setup() {
  // put your setup code here, to run once:
  // pinModes set as outputs for LEDs
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  //to call the function use: voidname();
  allLEDoff();  //call function to digitalWrite all LED pins low
  delay(dT);
  chase();        //runs the chase function
  dTchase = 125;  //changes the delay variable
  // the pattern continues gradually decreasing the delay so the LEDs appear to move faster
  chase();
  dTchase = 100;
  chase();
  dTchase = 83;
  chase();
  dTchase = 75;
  chase();
  dTchase = 62;
  chase();
  dTchase = 50;
  chase();
  dTchase = 38;
  chase();
  dTchase = 25;
  chase();
  dTchase = 12;
  chase();
  dTchase = 12;
  chase();
  dTchase = 8;
  chase();
  dTchase = 8;
  chase();
  dTchase = 5;
  chase();
  dTchase = 5;
  chase();
  dTchase = 4;
  chase();
  dTchase = 3;
  chase();
  dTchase = 2;
  chase();
  dTchase = 1;
  allLEDon();   // calls the function to turn on all the LEDs
  delay(3000);  // holds the LEDs on
  allLEDoff();  //calls the function to turn off all LEDs
  delay(6000);  // holds LEDs off
}

void chase() {  //this is where you digital write the LED pins on and off in chase pattern
  delay(dT);
  digitalWrite(bLED1, HIGH);
  delay(dTchase);
  digitalWrite(bLED2, HIGH);
  delay(dTchase);
  digitalWrite(bLED3, HIGH);
  delay(dTchase);
  digitalWrite(gLED1, HIGH);
  digitalWrite(bLED1, LOW);
  delay(dTchase);
  digitalWrite(gLED2, HIGH);
  digitalWrite(bLED2, LOW);
  delay(dTchase);
  digitalWrite(gLED3, HIGH);
  digitalWrite(bLED3, LOW);
  delay(dTchase);
  digitalWrite(yLED1, HIGH);
  digitalWrite(gLED1, LOW);
  delay(dTchase);
  digitalWrite(yLED2, HIGH);
  digitalWrite(gLED2, LOW);
  delay(dTchase);
  digitalWrite(yLED3, HIGH);
  digitalWrite(gLED3, LOW);
  delay(dTchase);
  digitalWrite(wLED1, HIGH);
  digitalWrite(yLED1, LOW);
  delay(dTchase);
  digitalWrite(wLED2, HIGH);
  digitalWrite(yLED2, LOW);
  delay(dTchase);
  digitalWrite(wLED3, HIGH);
  digitalWrite(yLED3, LOW);
  delay(dTchase);
  digitalWrite(wLED1, LOW);
  delay(dTchase);
  digitalWrite(wLED2, LOW);
  delay(dTchase);
  digitalWrite(wLED3, LOW);
  delay(dT);
}
void allLEDon() {
  digitalWrite(bLED1, HIGH);
  digitalWrite(bLED2, HIGH);
  digitalWrite(bLED3, HIGH);
  digitalWrite(gLED1, HIGH);
  digitalWrite(gLED2, HIGH);
  digitalWrite(gLED3, HIGH);
  digitalWrite(yLED1, HIGH);
  digitalWrite(yLED2, HIGH);
  digitalWrite(yLED3, HIGH);
  digitalWrite(wLED1, HIGH);
  digitalWrite(wLED2, HIGH);
  digitalWrite(wLED3, HIGH);
}
void allLEDoff() {
  digitalWrite(bLED1, LOW);
  digitalWrite(bLED2, LOW);
  digitalWrite(bLED3, LOW);
  digitalWrite(gLED1, LOW);
  digitalWrite(gLED2, LOW);
  digitalWrite(gLED3, LOW);
  digitalWrite(yLED1, LOW);
  digitalWrite(yLED2, LOW);
  digitalWrite(yLED3, LOW);
  digitalWrite(wLED1, LOW);
  digitalWrite(wLED2, LOW);
  digitalWrite(wLED3, LOW);
}