Advantech PCM-3362 user manual Software APIs, Gpio API

4.3.2Software APIs

PCM-3362 supports software APIs including GPIO, I2C, backlight on/off, Brightness control, watchdog, Hardware Monitor, and Power Saving.

4.3.2.1The 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.

4.3.2.2The 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 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.

4.3.2.3The 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.

4.3.2.4The 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 spe- cific 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.

4.3.2.5The Hardware Monitor API

The hardware monitor (abbreviated as HWM) is a system health supervision capabil- ity achieved by placing certain I/O chips along with sensors for inspecting the target of interests for certain condition indexes, such as fan speed, temperature and voltage etc.

However, due to the inaccuracy among many commercially available hardware mon- itoring chips, Advantech has developed a unique scheme for hardware monitoring - achieved by using a dedicated micro-processor with algorithms specifically designed for providing accurate, real-time and reliable data content; helping protect your sys- tem in a more reliable manner.

4.3.2.6The Power Saving API

1.CPU Speed

Chapter 4 Software Introduction & Installation

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