Odd behavior on ADC, please help!

Other Hardware General Electronics
3

The is a pro mini (5V, 16Mhz). It's running the following sketch:

void setup() 
{
  Serial.begin(9600); 

  pinMode(A1, INPUT);
  
  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() 
{  
  int sensorValue = analogRead(A1);   
  
  if(sensorValue > 520)
    digitalWrite(2, 1);
  if(sensorValue > 540)
    digitalWrite(3, 1);
  if(sensorValue > 560)
    digitalWrite(4, 1);
  if(sensorValue > 580)
    digitalWrite(5, 1);
  if(sensorValue > 600)
    digitalWrite(6, 1);
  if(sensorValue > 620)
    digitalWrite(7, 1);    
  if(sensorValue > 640)
    digitalWrite(8, 1);
  if(sensorValue > 660)
    digitalWrite(9, 1);
  if(sensorValue > 680)
    digitalWrite(13, 1);
  if(sensorValue > 700)
    digitalWrite(12, 1);
  if(sensorValue > 720)
    digitalWrite(11, 1);
  if(sensorValue > 740)
    digitalWrite(10, 1);   
  delay(1);
  
  //Serial.println(sensorValue);
  allOff();

}

void allOff()
{
  digitalWrite(2,0); digitalWrite(3,0); digitalWrite(4,0); digitalWrite(5,0);
  digitalWrite(6,0); digitalWrite(7,0); digitalWrite(8,0); digitalWrite(9,0);
  digitalWrite(10,0); digitalWrite(11,0); digitalWrite(12,0); digitalWrite(13,0);
  
  //delay(10);
}

Unfortunately, I have all the negative leads of the LED's connected together with the intention of grounding them which is why I cannot put them individually at the collector. Can I do the following to the same effect as the common-emitter arrangement?

Also, I'm running everything through USB so I can only supply up to 5V to anything. If I have 5V going to the collector and base, it shouldn't be a problem, right?

Thank you for you help!