All Coming Together

Today I started to work more on the programing. I got the receiving side mostly figured out. I got it so that when I point the laser at the photocell it will turn on an LED. Now all I need to do is replace the LED with a fire wire cable hooked up to a computer or camera. On the transmitting side I'm having some problems. The Arduino has two different types of ports in this instance a pin and a 5 volt port. The pin is hooked up to the program and the 5V pin just sends out power. I tested both with a multi tester and they both seem to have the same volts and amps. My problem is that I can operate my laser off of the 5V port but not the pin, but I can operate an LED off the pin or the 5V. This is a major setback until I figure it out. I also planned out my title and board with my dad.