GPIO

Introduction

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• A general-purpose input/output (GPIO) is an uncommitted digital signal pin on an integrated circuit or electronic circuit board which may be used as an input or output, or both, and is controllable by the user at runtime. GPIOs have no predefined purpose and are unused by default.
• When a pin is in GPIO mode, software has control over the high/low state of an output pin and direct read access to the state of an input pin. This is in contrast to the pin being controlled by a dedicated hardware function, such as a serial port.
• A GPIO port is a platform-defined grouping of GPIO pins. However, GPIO pins that are part of a GPIO port cannot be retrieved or controlled individually as GPIO pins.
• In order to use a specific pin or port, you should first open and obtain a GPIO Pin or GPIO Port instance for the pin or port you want to use.

IMPLEMENTATION:

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GPIO interfaces are simple—a group of pins that can switch as a group to either input or output. A GPIO port is a group of GPIO pins arranged in a group and pins in that can't be contolled individually. GPIO abilities may include:

• GPIO pins can be configured to be input or output
• GPIO pins can be enabled/disabled
• Input values are readable (usually high or low)
• Output values are writable/readable

Function Definitions:

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GPIO struct represents a single pin and GPIObitband ( ARM Bit Band Technology)

pub struct Gpio {

gpio: *mut GpioBitband,

pin: usize

}

Implementations:

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Impl make_gpio for Pin

pub fn make_gpio(self) -> Gpio

Converts a Pin into GPIO mode.