I have been trying with no luck to get the Raspberry Pi talking to an Arduino. I am using a 3.3 V-to-5 V converter to swap voltages. I did put an LED on the UART TX pin, and it looks like it was inverting the data. If this is true, what circuit do I need to get it communicating with the Arduino?
I am using a Cool Components Logic Level Converter. It is a transistor for 3.3 V to 5 V and resistor for 5 V to 3.3 V.