The VNC2 has 2 USB ports on it, you would make both of them the host ports for the temperature sensors. Connect the VNC2 to a PIC using the UART connection as a USB to UART bridge. The PIC does not need USB on it for what you are trying to do. I was unable to confirm if you can set up both USB ports on the chip as a USB host. If not, then you would need to use two of them, but since there are 2 USB ports built into the chip I would imagine you can. I have no real experience (yet) with this chip, but plan to get one in the near future to play with. Good luck, and keep us posted!