Led staying on after being pulled to a LOW state while using Millis()

Using Arduino Microcontrollers
1

A little background:
So I made a stand-alone Arduino using the atmega328-p QFN chip that incorporates NPN transistors in order to drive some LED's.

PCB layout:

Screenshot 2024-11-18 215206
Screenshot 2024-11-18 2152061224×667 22.5 KB

I'm having an issue where when using the Millis() function, the LED stays dim after a digitalWrite LOW is sent to the output of the microcontroller.

The strange part is that when using "delay();", The LED turns completely off instead of staying slightly dim when using Millis().

LED's when using delay:

IMG_8404-ezgif.com-optimize

LED's when using millis()

ezgif.com-video-to-gif-converter (1)

Here is the code that is using Millis()

unsigned long BIAUXms = 0;
unsigned long currentms=0;
void setup() {
  // put your setup code here, to run once:
pinMode(7,OUTPUT);
pinMode(8,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
BIAUX();
currentms= millis();
}

void BIAUX(){
  
  if(currentms-BIAUXms>=50){
    digitalWrite(8,HIGH);
  }
 if(currentms-BIAUXms>=100){
    digitalWrite(8,LOW);
  }
  if(currentms-BIAUXms>=150){
    digitalWrite(8,HIGH);
  }
 if(currentms-BIAUXms>=200){
    digitalWrite(8,LOW);  
  }
  if(currentms-BIAUXms>=250){
    digitalWrite(8,HIGH);
  }
 if(currentms-BIAUXms>=450){
    digitalWrite(8,LOW);       
  }
  //Swtich Leds
  if(currentms-BIAUXms>=500){
    digitalWrite(7,HIGH);
  }
 if(currentms-BIAUXms>=550){
    digitalWrite(7,LOW);      
  }
  if(currentms-BIAUXms>=600){
    digitalWrite(7,HIGH);
  }
 if(currentms-BIAUXms>=650){
    digitalWrite(7,LOW);  
  }
  if(currentms-BIAUXms>=700){
    digitalWrite(7,HIGH);
  }
 if(currentms-BIAUXms>=900){
    digitalWrite(7,LOW);
        BIAUXms=currentms;
  }
}

Here is the code that is using delay()

void setup() {
  // put your setup code here, to run once:
pinMode(7,OUTPUT);
pinMode(8,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(7,HIGH);
delay(50);
digitalWrite(7,LOW);
delay(50);
digitalWrite(7,HIGH);
delay(50);
digitalWrite(7,LOW);
delay(50);
digitalWrite(7,HIGH);
delay(175);
digitalWrite(7,LOW);
delay(50);

digitalWrite(8,HIGH);
delay(50);
digitalWrite(8,LOW);
delay(50);
digitalWrite(8,HIGH);
delay(50);
digitalWrite(8,LOW);
delay(50);
digitalWrite(8,HIGH);
delay(175);
digitalWrite(8,LOW);
delay(50);

}

Any help would be greatly appreciate!

2

Think about what the above snippet will do when currentms-BIAUXms is 899.

The LED will be turned on, then immediately back off. Followed by on/off/on/off/on/off... as fast as the processor can manage. So the LED will appear to stay on, though a little dimmer.

You need to rethink your code.

3

To add to my post, The 2 LED's are running of NPN 1 ( Digital Pin 7) and NPN 6 (Digital Pin 8). The LED that stays DIM after being set to LOW is digital Pin 7.

4

Thank you very much! I rewrote the code and it seems to work perfectly now!

unsigned long BIAUXms = 0;
unsigned long currentms=0;
void setup() {
  // put your setup code here, to run once:
pinMode(7,OUTPUT);
pinMode(8,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
BIAUX();
currentms= millis();
}

void BIAUX(){
  if(currentms-BIAUXms>=900){
    digitalWrite(7,LOW);
    BIAUXms=currentms;
  }
    else if(currentms-BIAUXms>=700){
      digitalWrite(7,HIGH);
    }
    else if(currentms-BIAUXms>=650){
      digitalWrite(7,LOW);  
    }
    else if(currentms-BIAUXms>=600){
      digitalWrite(7,HIGH);
    }
    else if(currentms-BIAUXms>=550){
      digitalWrite(7,LOW);      
    }
    //Swtich Leds
    else if(currentms-BIAUXms>=500){
      digitalWrite(7,HIGH);
    }
    else if(currentms-BIAUXms>=450){
      digitalWrite(8,LOW);       
    }
    else if(currentms-BIAUXms>=250){
      digitalWrite(8,HIGH);
    }
    else if(currentms-BIAUXms>=200){
      digitalWrite(8,LOW);  
    }
    else if(currentms-BIAUXms>=150){
      digitalWrite(8,HIGH);
    }
    else if(currentms-BIAUXms>=100){
      digitalWrite(8,LOW);
    }
    else if(currentms-BIAUXms>=50){
      digitalWrite(8,HIGH);
    }
 
  }