RETIRED - Using the Logic Level Converter
This Tutorial is Retired!
This tutorial covers concepts or technologies that are no longer current. It's still here for you to read and enjoy, but may not be as useful as our newest tutorials.
View the updated tutorial: Bi-Directional Logic Level Converter Hookup Guide
Contributors:
jimblom
jimblom 
Resources and Going Further
Here are some resources related to the LLC and level-shifting in general:
- Logic Level Converter Schematic
- Logic Level Converter Eagle Files
- Logic Level Converter GitHub Repo
- Philips AN97055 -- An awesome application note covering bi-directional level shifting circuits.
- 3V Tips 'n Tricks -- An informative document published by Microchip with lots of tips and tricks for interfacing between 3V and 5V systems.
Going Further
If you're looking for a place to use the LLC, these tutorials might spark some ideas:
- Electric Imp Breakout Hookup Guide -- The Electric Imp works at 3.3V max, so if you interface it with any 5V systems you may need an LLC.
- Getting Started with pcDuino -- The pcDuino is another 3.3V-based system. This is a powerhouse compared to the Electric Imp, though. It can run Linux or Android, and has all sorts of awesome functionality.
- Using the Arduino Pro Mini 3.3V -- If you want to stick with Arduino, and want to use 3.3V sensors, consider using an Arduino that runs at 3.3V. That way you won't even need to bother with an LLC!