This test run on Raspberry Pi 2/Raspbian Jessie (2016-05-27)
To run Raspberry Pi Configuration:
> Menu > Preferences > Raspberry Pi Configuration
Select Interfaces tab, and click to enable I2C, OK.
Install i2c-tools, such that you can scan any connected I2C devices, and find its I2C address.
$ sudo apt install i2c-tools
Power off Raspberry Pi, connect I2C device and power on.
run the i2cdetect with option 1 for rev 2 board, or option 0 for rev 1 board.
$ sudo i2cdetect -y 1
$ sudo i2cdetect -y 0
(The connected device with I2C address 0x3C shown in the video is a I2C OLED display, refer to next post: Raspberry Pi display on 128x64 I2C OLED with SSD1306, using Python)