A quick google for "3v to 5v transistor" gives me dozens of circuit diagrams that look like option A below with a NPN transistor and a pull-up resistor. If I build the diagram in iCircult, it works as expected. However, when I wire it up on a breadboard, it doesn't work quite the way it should. Without any power to the base, I get Vout = 4.95v. With power to the base I get Vout = 0v so it is inverting my wave.
A few experiments later, I solve my problem using a PNP transistor and a pull-down resistor (option B). In both cases I am taking Vout from the Collector side of the transistor.
It's a pretty simple circuit, you'd think it would just work. I double and triple checked the connections. I have also posted a photo of the breadboard below. I always seem to have weird problems like this when working with transistors, so now I am sort of on a quest to understand why option A doesn't work like it should for me?