One of the next things that comes up when trying to make the laser tag unit better is increasing the distance that you can send tags. What we want to do is to send the light coming out of our infrared LED further. There are two methods we can use to shine the light further. We can make our LED shine brighter, or we can use a lens to focus the light.
Adding a Transistor
We want to make the infrared LED shine brighter. In order to do that, we need to have more current (remember that from Lesson 1?). However, our arduino pin can only output 0.04 Amperes of current. We want to output 0.25 Amperes of current. That way, our light will be over 10 times brighter. But if we have that much current go through an arduino pin, that pin will be toast. Fortunately, there is something we can use to fix this problem. It is called a transistor. A transistor is an electrical switch. It turns on when you apply a voltage to it, and connects two pins. You can purchase transistors that can have much higher currents flow through them than an arduino pin.
We will add a transistor to our circuit in Lab 6 to make the infrared LED send a signal farther. To do that, we will go to Lab 6.