Power Limits of Arduino Duemilanove

I recently purchased the Duemilanove and am working on familiarizing myself with the board POWER limits so that I don't damage it. My questions are as follows:

  1. What is the max current that can be supplied through the VIN pin? Is this ultimately dependent upon the power source?

  2. What is the max current that can be supplied through the +5V pin? Is this also ultimately dependent upon the power source?

From the main overview on the Duemilanove, the following information is shown:

DC Current per I/O Pin 40 mA
DC Current for 3.3V Pin 50 mA

The power pins are as follows:

  • VIN. The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.

  • 5V. The regulated power supply used to power the microcontroller and other components on the board. This can come either from VIN via an on-board regulator, or be supplied by USB or another regulated 5V supply.

  • 3V3. A 3.3 volt supply generated by the on-board FTDI chip. Maximum current draw is 50 mA.

  • GND. Ground pins.

The voltage regulator has an 800ma theoretical, but real life you'll get about 500ma from it.

The higher the input voltage, the hotter the chip gets, and the less usable current supplied gets.

Connecting a few sensors, and a few LED's is more than fine.

If you're trying to hook up motors, or other high current draw devices, you'll need a second power supply.