GPIOPinIO Manual
Introduction
This manual describes the GPIOPinLib library and explains the purpose and usages of the library models - GPIOServer and GPIOPin.
GPIOServer
The GPIOServer is an I/O server that handles the updating (periodic reading/writing) of the GPIO pins. From the user experience perspective, it is a container for all the GPIOPin channels and a place where the user can conveniently configure them. For this purpose the GPIOServer component has a Section specifically for listing all the GPIOPins that have been added to it.
Usage
To set up a GPIOServer for an application simply add it as a subcomponent. To add a GPIOPin to the server navigate into it and add the GPIOPin from the resource tree or by using the in the Configuration editor.
GPIOPin
The GPIOPin represents a single physical input/output pin of an integrated circuit board.
Usage
When working with GPIOPins the most important properties are the following:
| Property | Description |
|---|---|
| Nr | Specifies the GPIO pin number (sometimes also referred to as the GPIO line number) that you wish to interact with (see the circuit board's documentation to determine the pin number). |
| Device | Specifies the device name in the operating system via the GPIO chip of the pin can be accessed (see the operating system documentation to determine the device name). Defaults to /dev/gpiochip0, which is the device for accessing the GPIO pins in older versions of Raspberry PI. Use device /dev/gpiochip4 to access GPIO-s in Raspberry PI 5 and newer. |
| Input | Specifies the pin direction from CDP. Set to True for controlling the output GPIO pin state from CDP. Set to False for reading the input GPIO pin state into CDP. |
| Routing | Specifies the signal routing that can be used for controlling the pin (if it is set as an input) or passing the pin's state to CDP. |
To interact (read/write) with a physical I/O pin the user must:
- Add a GPIOPin channel to a GPIOServer. See GPIOServer usage.
- Set the Nr property of the GPIOPin to the pin number of the circuit board.
- If the desire is to control the pin state with CDP, check the Input property checkbox to define that the GPIOPin accepts inputs from CDP. Otherwise, leave the Input property unchecked.
- Set the Routing property to point to a desired signal or another IOServer channel.
Warning: GPIOPin has a meaningful implementation on Linux only. On Windows it has just a dummy implementation.
See also GPIOServer, GPIOPin, and GPIO Setup Guide.
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