Suppose if I were to plug in my Arduino Nano into a USB hub which has one more device plugged to it, and it so happened that the devices maxed out the current limit they could draw from the USB port on my laptop, would it damage my the devices and Arduino board connected to the USB hub? Or would it simply just cannot power up the board that's all?
Nothing should get damaged. USB shuts down if you try to draw too much current.
fungus:
Nothing should get damaged. USB shuts down if you try to draw too much current.
But I remember a while ago when I had a short circuit which probably caused Arduino to draw more than 500mA from the USB, my Arduino board was blown immediately. Would my devices still be okay even if they don't have something like a polyfuse? I'm running on Nano and it doesn't have a polyfuse on it.
A short can only kill an arduino if the shorting occours through something on the board, or as a result of the power shouting down you get latch up because you are having indipendantly powered input to the now unpowered chip.
xEnOnn:
But I remember a while ago when I had a short circuit which probably caused Arduino to draw more than 500mA from the USB, my Arduino board was blown immediately. Would my devices still be okay even if they don't have something like a polyfuse? I'm running on Nano and it doesn't have a polyfuse on it.
If the Nano dies because of a short (and we don't know if it did) it's because wrong things were done to the Nano. That's not the same as plugging in another USB device on a hub.
Powering things with USB sucks. I have lost count of how many external hard disks have been corrupted by not getting enough power from USB.
hmm... Would this then corrupt the bootloader or sketches on Arduino if we don't supply enough power to it?
xEnOnn:
hmm... Would this then corrupt the bootloader or sketches on Arduino if we don't supply enough power to it?
No
Nothing should get damaged. USB shuts down if you try to draw too much current.
USB shuts down if you try to draw too much current
That is certainly true of any laptop. However, hubs are quite variable. Some current limit crisply at .5A. Others droop slowly as .5A is approached. I've got one that will happily send the full 2A supply which can actually be useful.
I do not recommend using USB as a current limiting supply. If this is a real problem you should own a proper supply with a current meter and limiting adjust. I bought one for 80$. Try ebay for the cheapest price.