Moving to the Bluetooth forum.
The Hardware User Guide is here: Hardware User Guide (SDK 2.x and TAG3 Board)
You will also want to familiarize yourself with the WICED Smart Hardware Interfaces
Yes, WICED Sense leverages the I2C bus to connecte multiple sensors to the BCM20737S SiP module.
Full source code for WICED Sense is available here on the forum: WICED Sense Table of Contents