Adafruit Motor Shield driving 12V motors

Hi
I think that I am probably going to purchase an Adafruit Motor Shield to drive 4 12V DC motors. Is it required to have an external 12 V source plugged into the shield or can I go off of the Arduino's power?

Thanks

Depends on the current of the motors. For 4 motors you're probably better off with an external power source. You will also have less issues with the Arduino magically resetting when you turn your motors on (a result of sharing the same ground path).

A good rule of thumb (IMHO) is not to draw more than ~500mA from the Arduino power (Vin). 4x motors will quite likely go above that.

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The Gadget Shield: accelerometer, RGB LED, IR transmit/receive, speaker, microphone, light sensor, potentiometer, pushbuttons

Cool. Now for an external power source for the shield, would a 9.6V source drive those 12V motors, or would I have to get some sort of a 12V source. I could live without all the extra power. In case you were wondering, I was looking at these motors: Maker Shed: Official store of Make: and Maker Faire since 2005

Thanks

Now for an external power source for the shield, would a 9.6V source drive those 12V motors, or would I have to get some sort of a 12V source.

Sure, you can always run motors at lower current.

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The Ruggeduino: compatible with Arduino UNO, 24V operation, all I/O's fused and protected