Wiring problems

Hi ATmega folks!

I’ll try to explain my problem:
I got an MPU6050 connected to 3.3v arduino’s pin and arduino’s GND and the same with motor shield connected to 5v and GND. I understand this is right due to the common GND. It’s the diferent voltage a problem?
I use the pc USB for the Arduino and a lypo battery for the motors(need high current).

I put a JPG as an attachment, so you can see what I’ve done(even if I got two motors).

I will learn and won’t be asking so stupid questions in the future.

Is there a problem ?

You need pull up resistors on the two I2C lines to 3v3 about 1K8. You also need to use a library that does not enable the internal pull-ups by default.

You can only get about 50mA from the 3v3 pin on that Arduino, is that enough?

3.3V regulator on Uno is good for 150mA. 3.3V from FTDI chip on Duemilanove, Nano, is only good for 50mA.

Which board are you really using?