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.

Alire Crates

	libsimpleio.pdf
	mcp2221.pdf
	remoteio.pdf

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/.
• 25 July 2021 -- Prebuild an Ada library project for the Linux Simple I/O Library Ada binding.
• 20 August 2021 -- An Alire library crate for libsimpleio has been published. Some more library crates for the Remote I/O Protocol and the MCP2221 USB I/O Expander are also forthcoming.
• 21 August 2021 -- Added experimental support for cross-compiling libsimpleio programs with cross-toolchains from the Debian package repository. You can cross-compile Ada, C++, and Go (and on Debian 11 Modula-2) programs, with certain limitations: No support for AWS, hidapi, or libusb. Just set the CROSS_COMPILE environment variable to select a cross-toolchain instead of a native compile:

  cd libsimpleio/ada/programs
  export CROSS_COMPILE=aarch64-linux-gnu-
  make test_hello
  

  Select cross-compiled libsimpleio packages have been added to the Munts Technologies Debian Package Repositories for Debian 10 (Buster) and Debian 11 (Bullseye).
• 3 September 2021 -- The Alire crates mcp2221 and remoteio have now been published.

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:

http://repo.munts.com/debian10

http://repo.munts.com/debian11

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.