powering arduino?

Hi guys,

I have a robot where the circuit is powered by 2 AA batteries and the adruino duemilanove is plugged into my computer with a usb. the circuit works properly when the usb is plugged in. but when i take it out, the microcontroller does not turn on.

how do i fix this?

Could you give some more details even a diagram or picture would be really helpful!

It sounds from that description that you haven't re-connected the power :P

/me

im not home at the moment so can’t make any diagrams or take pictures. but i guess to simply my problem more:

how can i use a battery to power my adruino board?

You need to put the positive into Vin and negative into GND on the power header.

http://arduino.cc/en/Main/ArduinoBoardDuemilanove

/me

perfect! thanks man :slight_smile:

I have a robot where the circuit is powered by 2 AA batteries

Two AA batteries will give you aboput 3 Volts, which isn't enough for an Arduino. You need about 7V, so you'll need five AA batteries at least, more likely six. You must connect the Ground of the Arduino to the Ground of the device you're trying to control.