And you can't have decisions involving weights under free will because...?
How is a calculated decision free?
Why wouldn't it be? This is your claim, so you must have some idea.
I can help you out a bit... Let's say you have a person deciding whether to eat a sandwich, or buy a hamburger. A sandwich is cheaper, doesn't taste as good, and takes less time to acquire. You've been claiming that a 'free decision' can't be 'caused by the inputs and their weights'. That could mean two things:
1) It could mean that a decision has to be determined by the relative weights of the inputs, and that it is impossible for a decision to involve weights without the decision being strictly determined by them. Free will can't comprise of strict determination. by definition, so free will decisions can't involve weights. All you'd need to do is prove that the first sentence there is true, that a decision has to be strictly determined by relative weights.
2) It could mean that a decision has to be either entirely strictly determined, or entirely random, and that no other states are possible. That essentially a variation on the 'free will is impossible because everything is either determined or random' argument. Again, you'd need to prove that the initial statement is actually true.
Either way, it's your job to explain why there's a problem with free will here. I can't really explain the solution to a problem that hasn't been identified.