power arduino and servo with the same battery

I have an arduino controlling a servo, each one has its own battery and works fine.

i would like to power both with the same battery but when i try the servo makes arduino restart. is there a way to avoid this?

Yes lots of power supply decoupling on the supply of the motor. Connect the motor's supply through an inductor and put a 0.1 ceramic capacitor from ground to each side of the inductor. Then put big capacitors in parallel with that start of with 100uF but you might have to go bigger.

You haven't said what sort of battery you are using. It needs to be able to provide a few amps of current so it can easily meet any short term demands by the motor without the voltage dropping. Plus what @Grumpy_Mike said.

...R

The inductor? (turns, diameter, . . ?)

vffgaston:
The inductor? (turns, diameter, . . ?)

What ever you can get hold of, the bigger the better about 10mH should be good but it is not critical.

The last circuit on this page:-
http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

What ever you can get hold of

Thanks a lot.