i set my coin slot into normally open state.so whenever i will drop a coin it should change its voltage from logic 0 to logic 1 right?but whenever i am measuring its voltage directly from the coin signal and to the ground,i only get a consistent 3V reading,it seems like it is not switching.,yielding to a non on and off state of the coin slot and counter for every coin dropped will not reflect to the PIC.then i connect a transistor to the coin signal going to the PIC.yet when i tried it to a simple program,and im not able to light the LED.