bindings-K8055: Bindings to Velleman K8055 dll

Description

This library allows you to control the Velleman K8055, a usb experiment interface board.

The board has:

• 5 digital inputs
• 2 analog inputs
• 8 digital outputs
• 2 analog outputs

How is works

Velleman provides a K8055D.dll, so this is a Windows-only solution, to interact with the board. A FFI interface has been written to interact with the dll functions. For this I had to create a definition file K8055D.def and run dlltool -k -d K8055D.def -l K8055D.dll.a.

Some Background

My first attempt at interfacing this board was using bindings-libusb. After getting is to work on Linux I was unable to compile it on Windows. Because my solution should work on Windows I chose to interface the existing dll.

I haven't given up on the my first solution, it's still the cleanest way to go, having no K8055 specific, native library dependencies and being platform-independent.

Install

As mentioned earlier, we need the K8055D.dll. This can be obtained by downloading the official Velleman K8055 SDK. Extract it and put the dll, DLL_v4.0.0.0/K8055D.dll, somewhere in PATH, e.g. C:\Windows\System32.

Then all you need to do is install the cabal package:

cabal install Bindings-K8055

Example

Press a button, digital in, an run the following code:

import Bindings.K8055

main :: IO ()
main =
  withDevice Card1 (readAllDigital >>= print)

Or using ghci:

> import Bindings.K8055
> withDevice Card1 (readAllDigital >>= print)
0