User manual

35 PCM-3343 User Manual
Chapter 5 Software Introduction & Installation
5.3.2 Software APIs
PCM-3343 supports software APIs including GPIO, I2C, backlight on/off, Brightness
control, and Watchdog .
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 out-
put 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 Philips for use in their tele-
visions 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 pro-
gramming 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 Display Control API
There are two kinds of VGA control APIs, backlight on/off control and brightness con-
trol. 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 embed- ded
device to easily control brightness.
2. Backlight Control
The Backlight API allows a developer to control the backlight (screen) on/off in
an embedded device.
5.3.2.4 The Watchdog API
A watchdog timer (abbreviated as WDT) is a hardware device which triggers
an action, e.g. rebooting the system, if the system does not reset the timer within a
specific period of time. The WDT API in SUSI provides developers with functions
such as starting the timer, resetting the timer, and setting the timeout value if
the hardware requires customized timeout values. For providing accurate, real-time
and reliable data content; helping protect your system in a more reliable manner.