Differences between PS2 devices and USB devices?

[jeffmorris]

What are the differences between PS2 devices and USB devices? For example, PS2 and USB keyboards. PS2 devices can be connected directly into Arduino boards and USB devices must be connected to USB host boards. Is it possible for me to hack an USB mouse and connect it to Arduino board as if it is PS2 mouse?

[Osgeld]

ps/2 and usb are two completely different beasts, though many USB mouses will work in ps/2 mode, usually a good tip off is if they came with one of those little green adapters

[jeffmorris]

I tried the green USB to PS2 adapter and it worked.

[Zapro]

I tried the green USB to PS2 adapter and it worked.

You do not need the adaptor, there is no electronics inside it. Just use the USB plug and test out which wire is CLK and which is DATA, power/ground in the USB cable is red/black, so that is simple enough.

// Per.