tasasaki:
A Sparkfun 9DOF sensor stick seems to need a power supply which outputs 3.5V or more...SparkFun 9 Degrees of Freedom - Sensor Stick - SEN-10724 - SparkFun Electronics
Hm are you sure? I don´t know physics very well. But this guy seemed to get it working with 3.3V and I followed this tutorial Connecting to Sparkfun’s 9DOF “Sensor Stick”: I2C access to ADXL345, ITG-3200, and HMC5843 | Chionotech
this guide uses a different stick, but this one also runs on 3.3V http://www.instructables.com/id/Guide-to-gyro-and-accelerometer-with-Arduino-inclu/
and, last but not least, this schematic (can´t read it really. Just intuition) says all the I/O 3.3V http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/IMU/9DoF-Stick-v13.pdf
This guy in the comments say:
It’s a MIC5205 3.3V. This is an LDO regulator, so VCC only needs to be above 3.5V.
Can this be right? Maybe he did a mistake and he meant "so VCC only needs to be above 3.3V"? Or do I have to calculate something there to get the 3.5V? The MIC5205 spec does not say anything 3.5V.