Unexpected waveform results

Glad you got it sorted out.

You might want to give more details of your solution to help others in the future.

Rick G

Stumbled upon your problem researching something else.

Making the level shift is pretty trivial, and while this is not an IC, it's cheap enough that making it yourself is probably not worth your time. You mentioned arduino, so are probably familiar with sparkfun:

www.sparkfun.com/products/8745

Simple mosfet shifter, your application would just need TX LV on the port side and TX HV on the controller side, plus power. Each board can do 2 pins, the RX feature (which is um, not very good IMHO looking at the schematic) is unused.

You still get to hack up a wallwart and add a couple linear regulators (3.3V and 5V, add a couple caps for filtering for good measure if you like.)

If you simply must get an IC and make a board, etc, look at CD40109.