The CY3640 has been discontinued. The current drivers can be found here. We recommend that customers use the provided drivers without modification.
The CY3640 thermometer driver was developed by a third party when we introduced CY3640. At that time, there was no HID driver, so a custom driver was provided for the application.
To reduce the burden of writing a custom driver as in our thermometer example, you might want to take a look at the HID application example written by Jan Axelson. In her example, Jan utilizes the Windows built-in HID driver to send/receive 2 bytes, and she has sample codes based on both the CY630/1xx and CY637xx. For more info, go to www.lvr.com