Arduino 3.3V Conversion I am fairly new to Arduino. As far I know all official Arduinos run on 5 volts. Or there is Arduino versions that run from 3.3V? I need use Arduino with devices which chipsets all use 3.3V logic level. Do I need modify Arduino to make it  3.3V powered, like described in this Tips, or there is another way? I plan get Arduino UNO R3 ATmega328P board (comes with bootloader for Arduino UNO ZT).
Arduino Pro Mini comes in 3.3v and 5v versions.