Interfacing with usb mouse, would this idea work?

I've gone through Martijn The's process of reading x/y data from an optical mouse, martijnthe.nl/2009/07/interfacing-an-optical-mouse-sensor-to-your-arduino/ and have been going through forums and posts and have seen a few questions regarding using the same process to feed data into the mouse (or other mouse).

Going through the datasheet for the optical sensor, that SDIO pin is only available as a read value, no write ability. But writing to the sensor wouldn't really make much sense anyway.

Tracing the SDIO pin from the sensor, it goes directly to the microprocessor (only other chip on the board, so I'm assuming that's what it is, and I found a similar datasheet to the one on my mouse microblog.routed.net/wp-content/uploads/2007/01/ma6221-s7k.pdf).

So, in theory, couldn't i cut the wire to the sensor, and connect that directly to digital I/O on the arduino? That way I'm in theory getting a USB HID interface (possibly wireless to boot!).

However, it seems to simple that this would work, and hasn't been done already, as there seem to be some discussion as to using HID and Teensy, serial to usb converters, etc.

Would somebody be able to explain to me why this wouldn't work (if it won't)?

Also, if it is worth a shot, any idea what data comes from the SLCK pin? The data won't be coming from the sensor, so I'm guessing I'll need to push that through too.

If this doesn't work, I can of course get a teensy, and build from there, but I thought this might be worth a shot.

Wow, sorry to have been so unclear in my initial post. Thanks for taking the time to ask questions and not just ignore the post.

I have got Martjin's technique for reading x-y coordinates from the sensor.

What I am attempting to do is control the cursor on screen, first just with code written on the arduino, and then using inputs buttons, switches, accelerometer, who knows what else.

I can appreciate that writing to a mouse doesn't make much sense. I supposed it would be better stated that i am attempting to use the mouse-to-pc interfaces which are already created, rather than trying to write complete HID interfaces which seems very complicated.

Hopefully I've made that clearer.

Thanks again.

Or are you trying to use an Arduino to simulate a USB HDI mouse so you can use other kinds of transducers to simulate mouse movements? That would seem more like simulating a USB mouse, rather than interfacing with one. You would be interfacing with the USB interface on the PC.

Yes, this is what I am trying to do, use arduino to simulate a USB mouse. I have been unable to find a method for doing this.

Coming from a software programming background, I was breaking into steps get data, put data, etc,etc. Maybe that isn't the correct methodology to be using.