Wetif VMT12, User Manual

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5.3.2 Software APIs
5.3.2.1 The GPIO API
General Purpose Input/Output is a flexible parallel interface that allows a
variety of custom connections. It allows users to monitor the level of
signal input or set the output status to switch on/off a device. Our API also
provides Programmable GPIO, which allows developers to dynamically
set the GPIO input or output status.
5.3.2.2 The I2C API
I2C is a bi-directional two-wire bus that was developed by Phillips for use
in their televisions in the 1980s and nowadays is used in various types of
embedded systems. The strict timing requirements defined in the I2C
protocol has been taken care of by SUSI. Instead of asking application
programmers to figure out the strict timing requirements in the I2C
protocol, the I2C API in SUSI can be used to control I2C devices by
invoking other function calls. SUSI provides a consistent programming
interface for different Advantech boards. That means user programs using
SUSI are portable among different Advantech boards as long as the boards
and SUSI provide the required functionalities. Overall product
development times can be greatly reduced using SUSI.
5.3.2.3 The SMBus API
The System Management Bus (SMBus) is a two-wire interface defined by
Intel
®
Corporation in 1995. It is based on the same principles of operation
of I2C and is used in personal computers and servers for low-speed
system management communications. Nowadays, it can be seen in many
types of embedded systems. As with other API in SUSI, the SMBus API is
available on many platforms including Windows XP and Windows CE.
5.3.2.4 The Display Control API
There are two kinds of VGA control APIs, backlight on/off control and
brightness control. Backlight on/off control allows a developer to turn on
or off the backlight, and to control brightness smoothly.
1. Brightness Control
– The Brightness Control API allows a developer to interface with an
embedded device to easily control brightness.
2. Backlight Control
– The Backlight API allows a developer to control the backlight