I just got my very first Arduino Uno, and I've been playing around with the lessons and and looking to take the next step into something more creative. I am more of a programmer than and electronics guy, so I apologize if my question is badly phrased or very vague or even uneducated :
How much power can I safely get out of my Arduino Uno? More specific, what numbers, measurements, and calculations should I look at before attaching sensors and LED components to my board, so I can power everything effectively and not fry my stuff?
Thanks for any help!
The basic board consumes about 25-50ma of +5vdc current. The current avalible to be drawn from the shield +5vdc power pin or output pin(s) depends on what power source is being used. USB is limited to 500ma total by a on-board thermofuse. The external connector's current capacity is limited by the heat dissapation of the on-board +5vdc regulator so is somewhat dependent on how high the external voltage is being applied to the board. Keeping all loads (board and external components) at under 500ma max or less is probably the good rule to follow. However there is nothing to prevent you from using external DC power sources to supply higher current loads like motors and solenoids, etc, there is just a need to interface such high current devices to a arduino through switching devices like transistors, relays, etc.
The arduino is great at controlling external components, but not really designed to power such devices.
Each Arduino digital output pins can provide +5vdc current, but each pin is rated at absolute max of 40ma (don't use that amount), but one should keep it limited to 20ma or so max. All digital pin output current combined needs to be 200ma or less.