The Raspberry Pi family of processors consists mostly of inexpensive but full-featured single-board computers running a Linux operating system; others are stand-alone Micro Computer Units (MCUs) not running any Operating System (OS) at all. But Raspberry Pi computers also contain a set of General Purpose Input and Output (GPIO) Pins that allow "physical computing", i.e. the direct interaction of these computers with their physical environment via electrical signals that are both fully programmable and readable under program control. To aid in the programming and examination of these electrical signals in Python, the go-to-programming-language on the Raspberry Pi, there exist several Python packages, such as pigpio, smbus, and smbus2, to name just the most popular ones. All do more or less the same thing, have their own strengths and weaknesses but usually also have different Application Programming Interfaces (APIs). Some of them are aptly documented; others are not. There is basically no guidance for the uninitiated as to when to use which, and, in fact, depending on which GPIO functionality one needs, different packages have advantages over others, so it is often not possible to work with only one Python package. To make matters worse, the Raspberry Pi family of processors also contains an MCU, the Raspberry Pi Pico, which has its own set of packages to handle GPIO, of course again with their own API. To help navigate this "freedom of choice," which is highly praised in some parts of the Free and Open Source Software (FOSS) community, but otherwise often just referred to as mess, this GPIO_AL package was designed. It provides a common API across all Raspberry Pi platforms, including the Raspberry Pi Pico, and uses the most appropriate packages for each individual task "under the cover" and completely transparently for the programmer of higher level applications. In other words, it forms an Abstraction Layer (AL) above the hardware and the plethora of its drivers with a consistent API across all platforms. Thus, a particular "physical computing" application can be coded on one Raspberry Pi platform and then transferred to another without any code modifications.
In its humble beginnings, this GPIO_AL package consists of a class to handle the configuration of I/O Pins, setting and reading their voltage levels, and the ability to have user-code called whenever the voltage at those Pins changes. It further contains a class to handle I2C bus communication with peripheral devices, a communication scheme that has become vastly popular in recent years for a plethora of sensors. Lastly, it contains an exception class to indicate that something went wrong and detailing exactly what and how severe it was.
For a complete documentation of this Python module, please see the docs directory https://ekkehard.github.io/RBPiGPIO_AL/.
- Rev. 1.0.0 -- Initial commit
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Please see the LICENSE.md and CNOTICE.md files for more detailed license information.