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 libK8055D.a.
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.
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_v220.127.116.11/K8055D.dll, somewhere in PATH,
Then all you need to do is install the cabal package:
cabal install Bindings-K8055
Press a button, digital in, and try the following ghci code:
> import Bindings.K8055 > withDevice Card1 (readAllDigital >>= print) 0
Or compiled. Watch out, you need the
libK8055D.a interface library, which was packaged in this cabal
package and was probably installed in
%APPDATA%\cabal\bindings-K8055-0.1.2. By putting it in the
ghc-<version> it should be found by the compiler.
import Bindings.K8055 main :: IO () main = withDevice Card1 (readAllDigital >>= print)