https://hackage.haskell.org/package/wiringPi-1.0 https://github.com/ppelleti/hs-wiringPi I released wiringPi-0.1.0.0 less than two weeks ago, but already I have a new major version, with a breaking change. wiringPi-0.1.0.0 kept close to the C wiringPi library, which required calling a setup function. There were four different setup functions, and the choice of setup function determined the pin numbering scheme, which would affect all subsequent functions which used pin numbers. This sort of far-reaching global state felt very un-Haskell-like, and antithetical to modularity. So, in wiringPi-1.0, the setup function is called automatically the first time a wiringPi function is used. The wiringPi binding always configures the underlying C library to use the "Broadcom GPIO" pin numbering scheme. However, the Pin type now has three different constructors, to allow a pin to use any of the three pin-numbering schemes. These pin numbers are automatically converted to the "Broadcom GPIO" scheme internally. So now you can use any pin numbering scheme on a case-by-case basis, without having to make a global choice. About wiringPi: This is a Haskell binding to the wiringPi library, which allows you to interface with the GPIO pins on the Raspberry Pi. Unlike some other solutions for using the Raspberry Pi's GPIO pins, wiringPi provides access to more advanced features, such as enabling the internal pull-up or pull-down resistors. --Patrick