I want to run two BMP085 pressure sensors from one I2C circuit. The data sheet says you can do that by setting the XCLR pin to silence one device while you read the other. the problem is the pressure sensor uses 3 volts and the output pins on the UNO are 5 volts and when used the data is incorrect. How can I get 3 volts for the output pins?
I had the same problem, with my main project's sensor suite... The bulk of the sensors were running on 5v and the BMP085 would only do 3.3v.
I ended up buying one of these (http://www.sparkfun.com/products/8745) to sort the problem out. I still need to get it connected and soldered into place, but the thread I started in the Communication part of this forum seems to suggest that it will do the job.
You can try an I2C multiplexor (DssCircuits.com is for sale | HugeDomains ) which takes care of the voltage level translation at the same time letting you connect up to 4 I2C devices with the same address.