Power Options

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I discovered earlier, that I would need an external power supply to drive the servos and that it would need to power the Arduino as well so that the grounds are common. This is no problem as I don't plan on having my clock plugged into the USB port on the computer all the time. I bought some stuff to build my own "Servo shield" to plug in the servos. It's a piece of breadboard and some header pins to connect it all. I was thinking that I would need to split the 5V power leads to provide separate (but equal) power to the servo board and to the Arduino, but I was wrong.
On the Arduino boards, there's a pin marked "Vin" on the Arduino UNO (or 9V on older models) that provides pass-through power when using external power. This is not the limited 5V regulated power to the Arduino, this is the unmodified power from the external supply. (The same pin can be used to power the board if desired.)
My servo board just got really simple. I bring the power and ground from the external supply and provide them as a bus for the 5 servos. I plan on connecting servos to digital pins 2, 3, 5, 6 & 7. Pin 4 is used to switch on the SD card slot on the Ethernet Shield, and pins 10-13 are used to control the Ethernet port. If I need to add other stuff later (perhaps a chime) I still have all my analog pins and a couple digital pins leftover.

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