Ok, i m a total noob concerning Arduino but i ll definitly learn everything about it if the thinkg i want to build is possible with it.
Heres what i want to do :
Let 's say i have a wacom tablet (usb), i want to make it wi fi, so i use arduino to make a usb to wi-fi module (+ power ) and i want that the receiver of that wi fi signal is an iphone or ipad with a custom app that can read the strokes drawn on the tablet.
Is that possible ?
regards
The Arduino is a USB slave and the waco tablet is a USB slave. Slaves don't talk well to each other. You need a USB host shield (sparkfun) and then still you have to write a driver for it. Look for USB HID drivers or so. Done that you need to add wifi caps to the app (sparkfun has a wifi shield too) .
A (tiny) bit realistic option imho is to use the FEZ board (www.tinyclr.com), it has a USB host on board and in the manual there is an example for an USB mouse (and I can confirm that the code works) if the waco tablet can "talk mouse" that part of the equation would become a "copy/paste" project. The FEZ states its hardware compatible with Arduino shields, so add a wifi shield and extend the code with some networking. (no experience).
Said all that and suppose it works, ..... than your PC should have a way to talk wifi to the arduino and translate that to a something the tablet driver understands. Again a big project on its own.
No I don't say its impossible although I think it is way^3 beyond a beginners project.
Not cheap but this claims to do the job WiRanger® - Icron Technologies Corp.
Note: I do like this kind of dreaming! So don't loose the dreams but try something less big first 
Thanks for the pointers !
i know it s beyond beginner level, but i have a friend who can help me for code and stuff, i m just doing R&D and then come to a sketch about i want to do and assist him while he s building and coding it.
but definitly want to do the R&D myself !
thanks again 
HOST shield - SparkFun USB-C Host Shield - DEV-21247 - SparkFun Electronics
WIFI shield - SparkFun WiFly Shield - WRL-09954 - SparkFun Electronics
I remember the first Wacom I had was RS-232! Then I had an ADB Wacom. My current Wacom is USB. Instead of wifi, I wonder if it may work suitably if you tried bluetooth instead as a way of getting the data to the handheld device.
Ok thanks
Just gathering infos, if it so hard to make i ll put it aside
but i know it has been made i can give you a link in pm of a video showing what i want to achieve, i know it's based on a Usb Tablet.
If you really want to go down this path,
I'd take a look at the teensy boards: Teensy USB Development Board
IMHO, teensy is a much better platform than the official Arduino for something like this.
Not to mention that for less money you get up to 4 x the memory and i/o pins.
Teensy boards support the Arduino toolset and libraries but also have REAL usb support in hardware. This means that with just software changes, the board can behave like any usb device, and more importantly, a USB host which is what you will need to talk to your USB tablet which is a USB device.
USB host is something that the standard Arduino boards cannot do.
Well, they can but they must bit bang the USB interface to do it, and that is very complex very time critical code that consumes nearly 100% of the cpu so it does not really work with Arduino software.
Combine a teensy board, along with a Bluetooth serial device that creates a virtual com port back to your host, iphone/ipad in your case,
(using something like this: http://www.nkcelectronics.com/bluetooth-module-serial-port.html)
and you can do whatever you want by simply using serial messages
between the AVR and the iphone/ipad app.
The teensy would act as a USB host to the tablet, then use serial to talk to the bluetooth module which talks to the iphone/ipad (not sure if the iphone/ipad is a master or slave or can be either).
You could literally mount the bluetooth module on top of the teensy++
using a strip/protoboard and have a very compact solution.
If your tablet is usb powered, you will have to have supply enough
power to the teensy to run the tablet too.
The biggest challenge will be to write the code (driver) to talk to the tablet that will be running on the teensy.
Looks like you could review some working source code
(http://linuxwacom.sourceforge.net/) to help understand
the interfaces to the tablet.
While definitely doable, it is definitely not a beginner project.
--- bill
thanks again for all those great advices; once again i know it"s not a beginner level.
if i have some linux experience and as you mentionned using linux code for the driver of the tablet should i benefit using instead of arduino the chumby hacker board ? Sensor tutorials
i d really want ahdhoc wifi instead of bluetooth because of the range ( i need the longest range possible for the application i want to use it for ).
Old arduino can use the host shield and the Uno's usb chip can be reprogrammed to be a usb host. The host shield seems to be the best choice.
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1288115951
I am not certain the arduino can read the data from the tablet. Would you be willing to try a touch screen and have it send the data?
Here is the wishield
http://www.asynclabs.com/store?page=shop.product_details&flypage=flypage.tpl&product_id=26&category_id=6
http://www.liquidware.com/wikipages/name/TouchShield
I'm not sure if they are compatible and they are not cheap. I've not used them so you'll have to read documentation and/or ask before purchasing.