Powering Ardunio UNO from 9 Volt battery and connecting it to USB

Hi all

can i use a 9 volt battery to power on my Ardunio ?

i tried to power my Arduino from raspberry pi the Arduino powered up but it could not run a motor (it have a different external power source for the motor) so i want to power my Arduino from a 9 volt battery and connect it to the raspberry pi to make serial communication.

1-will my plane work ? 2-is it ok to power Arduino from the external port and the USB together ? 3-Can i use the same 9 volt battery to power up the Arduino and the motor together ?

How did you connect it? Did you connect all the GND lines of everything together?

yes i had connected the motor and the arduino ground together

How did you connect the Arduino to the Raspberry Pi?

A battery will work, but I think it should work from the Pi if you have an external supply for the motor.

Battery won't last long driving a motor. Better to use 6xAA battery pack.

Arduino will operate from battery while Vin/2 is > 3.3V. Vin comes from the barrel jack and the reverse polarity diode, so the barrel jack needs to be ~ 7.3V.

How are you connecting to the motor? Some transistor that you control from an arduino pin?