A Start condition occurs when there is a high-to-low transition on
the SDA pin while the SCL pin is at a stable logic ‘1’ state and will
bring the device out of Standby mode. The master uses a Start condition to initiate any
data transfer sequence; therefore, every command must begin with a Start condition.
The device will continuously monitor the SDA and SCL pins for a Start condition but will
not respond unless one is detected. Refer to Figure 1 for more details.