I was thinking of using a BMP085 pressure/temp sensor with a 5V arduino and I started looking into level shifting. There are at least two breakout boards (one from Adafruit and one from Sparkfun) and a several ICs with 4050 somewhere in their names. I'm confused. I want to connect the BMP085 to the i2c bus along with a 16x4 i2c screen and DS1307 RTC both operating a 5V.
What's the best (bi-directional?) level shifter to use to connect BMP085 (which has to operate a 3.3V) to the i2c bus with the other two 5V devices?
I was thinking of using a CD74HC4050E which I think is pretty much the same as the 4050 level shifter in the Nokia 5110 tutorial.
I did that tutorial with CD74HC4050E and checked that the signal (on my DSO quad) going into the Nokia screen was getting pulses about 2/3 as big as the stuff coming out of the arduino pins. (I never bother to calibrate the DSO, b/c it seems like I get annoyed and try another firmware like every other day.) So it seems to work fine. Will this shifter work with i2c?