Potentiometer Readings Off

[groundFungus]

@xXDukeNukemXx

 if (digitalRead(BTN1) == HIGH)  // ****** this checks if the button was pressed
  {
    digitalWrite(LED_GO, HIGH);
    START = true;
  }

In the if structure, you check for a HIGH to see if the button pressed. If you change the switch wiring to an active low (LOW when pressed), you also need to change the if to look for a LOW when the switch pressed.

@xXDukeNukemXx

if (digitalRead(BTN1) == LOW)
  {
    digitalWrite(LED_GO, HIGH);
    START = true;
  }