I already went to your tutorials Nigel, actually, you made a good job, it's much better than the datasheet.
I've tried to debug my code, by setting breakpoints as advised by Pommie, and thanks to that, i've found my mistake !
Instead of doing
i did
The result of my conversion was good, but when I tried to retrieve the value in my variable conv1, i didn't get the right result, as i didn't use the right instruction !
Now I think it's gonna work well !
Thanks all =)