I want to connect an Arduino Nano to an Intel Minnowboard Max (it's like a Raspberry Pi). I know Arduino can draw up to 500 mA current through the USB connection. Since I already need the USB to communicate the Arduino with the Minnowboard, it would be nice to not power the Arduino separately as well. However, I wouldn't want the current the Arduino draws from the Minnowboard to overheat Minnowboard's 2.5A 12V power supply. I only have 8 buttons connected to the digital pins of the Arduino Nano. Nano sends the state of the buttons to the Minnowboard via USB (serial). How much current is Arduino drawing in this case?
I would guess around 50 mA, to power the processor and the USB converter. I notice that this question suggests more like 20 mA.
To be certain, you could measure it, but probably 20 to 50 mA would be a ball-park figure.