Arduino freeze when on battery and USB

[llima]

Hello,

A few months ago I decided that I wouls build a quadcopter, after ome research on control boards, and since I already owned an arduino mega I decided that I would build my own control board, to suit my needs.

Like everyone else I had to get through all the problems with vibrations, and setting up parameters, but eventually I got it to fly nicely.

However, suddenly the quadcopter started having some unexpected behaviours, that I wonder if anyone of you experienced.

Some times when I plug the battery, the quad boots, but it then freezes completely, no response. This always happens also when I plug the battery with the quad connected to the USB. The multiwii software just freezes. This made me think that it should be an hardware issue. In attachment is the control board schematic, I am using a GY-86 sensor, which I do not trust a lot, but I also tried it with a MPU6050 breakout with the same results.

Any ideas or past experience anyone has to share are very apretiated.

[scrat]

Never plug in the battery when you have USB connected at the same time.