I'd like to drive 3 servo motors for a simple robotic arm (each of which could draw 500mA at max load). I am thinking either I power the board with a supply that has, for example, 9V & ~1.5A and draw from Vin? Alternatively, are there specialized Arduino servo boards out there with separate motor/microcontroller power supplies inputs and servo connector pins? Or would I be better off designing a custom PCB?
Thank you very much!
You might like to have a look at Lynxmotion's BotBoarduino
Looking at the Uno's specs, I don't see anything about current available from Vin... It will be interesting to see what the gurus say on that score. But of course there's nothing to stop you giving the servos their own power while controlling them from 3x Arduino pins.
I use a Dagu spider controller on one of my robots. It's based on an Arduino Mega 1280 and has a 3A switch mode regulator. It has 3 pins (signal/5V/GND) for every input/output. Which makes it very easy to hook up sensors and servos. Sparkfun sells it: https://www.sparkfun.com/products/11498
I then started designing my own boards using 3A switch mode regulators and 3 pins for every I/O. I have made a board with an ATmega328 and another with an ATmega1284. I have used the one based on the ATmega328 on a hexapod with 12 small servos.
http://www.bajdi.com/something-different-a-crash-robot/bajduino-mega-3a-2/
http://www.bajdi.com/?attachment_id=536