Linux Simple I/O Library

libsimpleio is an attempt to encapsulate (as much as possible) the ugliness of Linux I/O device access. It provides services for the following types of I/O devices:

• Industrial I/O Subsystem A/D (Analog to Digital) Converter Devices
• Industrial I/O Subsystem D/A (Digital to Analog) Converter Devices
• GPIO (General Purpose Input/Output) Pins
• Raw HID (Human Interface Device) Devices
• I²C (Inter-Integrated Circuit) Bus Devices
• Labview LINX Remote I/O Devices
• PWM (Pulse Width Modulated) Output Devices
• Remote I/O Protocol Devices
• Serial Ports
• SPI (Serial Peripheral Interface) Bus Devices
• Stream Framing Protocol Devices
• TCP and UDP over IPv4 Network Devices
• Watchdog Timer Devices

Although libsimpleio was originally intended for Linux microcomputers such as the Raspberry Pi, it can also be useful on larger desktop Linux systems.

The C wrapper functions exported by libsimpleio all follow the same uniform pattern:

• All C wrapper functions are proper procedures (void f() in C).
• All input arguments of primitive types (int, float, etc.) are passed by value.
• All output arguments of primitive types are passed by reference (int *, float *, etc.).
• All composite types are passed by reference.
• int32_t is used wherever possible for int and bool arguments.

All of the C wrapper functions are declared between _BEGIN_STD_C and _END_STD_C for C++. Binding modules are provided for Ada, C#, Java, and Free Pascal. Additional source code libraries are provided for Ada, C++, C#, Java, and Free Pascal that define OOP (Object Oriented Programming) classes for libsimpleio.

Quick Setup Instructions for the Impatient

Instructions for installing libsimpleio are found in UserManual.pdf, on pages 5 and 6.

News

• 10 February 2021 -- Added support for GPIO output pins implemented using PWM outputs. This is useful for controlling an ON/OFF device such as an LED or solenoid valve driven by PWM output.
• 18 March 2021 -- Modified the package building procedure to only install the absolute minimum files for the MuntsOS cross-compiled packages. An issue with dpkg installation script execution order may require you to run the following commands after upgrading to this version of libsimpleio:

  sudo find /usr/local -name '*-tmp' -exec rm {} ";"
  sudo apt install --reinstall munts-libsimpleio
  

  If you have previously installed the MuntsOS cross-compiled packages, you will also need to run one or more of the following commands:

  sudo apt install --reinstall gcc-aarch64-linux-gnu-muntsos-crosstool-libsimpleio
  sudo apt install --reinstall gcc-arm-linux-gnueabihf-muntsos-beaglebone-crosstool-libsimpleio
  sudo apt install --reinstall gcc-arm-linux-gnueabihf-muntsos-raspberrypi1-crosstool-libsimpleio
  sudo apt install --reinstall gcc-arm-linux-gnueabihf-muntsos-raspberrypi2-crosstool-libsimpleio
  

• 25 March 2021 -- Added some rudimentary Python client support for the Remote I/O Protocol for raw HID servers (like this or this), in response to a request from a customer who wants to develop a Python Remote I/O Protocol client program that can run on Windows 10 64-bit. Accomplishing this requires a new Windows shared library libremoteio.dll, which was written in the Ada programming language. It also contains the latest hidapi code. Precompiled library files have been added to win/win64/. A few "proof of concept" Python3 programs are in python/.
• 29 March 2021 -- The new libremoteio.dll also works with Visual Studio C++ programs. Added some Visual Studio C++ projects for creating Remote I/O Protocol client programs for 64-Bit Windows 10.
• 20 April 2021 -- Added support to SERIAL_open() for more baud rates above 1000000 bps. Fixed issue with raw mode on Raspberry Pi serial ports.
• 18 May 2021 -- Added support for stepper motors to Ada and .Net. Renamed basic/ to mybasic/, modula2/ to gm2/, and pascal/ to freepascal/.

Documentation

The user manual for libsimpleio is available at UserManual.pdf.

The man pages specifying the libsimpleio API are available at libsimpleio.html.

Git Repository

The source code is available at:

https://github.com/pmunts/libsimpleio

Use the following command to clone it:

git clone https://github.com/pmunts/libsimpleio.git

Package Repository

Prebuilt packages for Debian Linux are available at:

Make With Ada Projects

• 2017 Ada Embedded Linux Framework
• 2019 Modbus RTU Framework for Ada (Prize Winner!)

I am available for custom system development (hardware and software) of products using ARM Linux or other microcomputers.