Taxes: Donating vacation home rental for charity

I'm thinking about donating a week's use of my Florida vacation home to a local soup kitchen, which would auction it to raise funds. Since I normally rent out the home during that time of year, could I write off the amount that the high bidder pays as a charitable donation?

No. Moreover, even if the high bidder pays fair market rent, the IRS will consider that week personal-use rather than rental time. That won't matter if you primarily use the home as a second residence and just rent it out periodically to bring in some extra cash. But if you want to minimize your use of the home so you can treat it as a rental property for tax purposes, donating the time to charity will work against that goal.