Dll in vvvv

vvvv beta general
#1

hello all, newbie question on vvvv…
is it possible to execute commands nestes in a dll? e.g. i have a velleman-kit (K8055 connected via usb) and want to execute some commands to communicate with the card.
do i need a special device driver for it?

any one an idea?

thanx
wolfgang

#2

you´d need a new vvvv release. you can not use arbitrary dlls from within vvvv

some workarounds are possible:

  • try to reverse engineer the velleman kit. while i havent seen one, i think it is very unlikely that it is not based on one of the few commercially available virtual com port chips. look for the name and vendor of the usb chip and see if there is a generic driver available from the chip vendor. using that driver you should be able to control the board over a virtual com port. if so, anything the dll does can be easily simulated within vvvv by using the RS232 node.

  • write a small command line application to control your device using the dll. use something like gnu-c or turbo-pascal. Use ShellExecute within vvvv to call the program for setting the individual bits.

  • write a small application which responds to data received on a socket. use the TCP or UDP nodes within vvvv to communicate with your application using the ip adress localhost or 127.0.0.0

  • write a small application which responds to windows messages. use the HWND/SendMSG nodes to send data to your application - tell us your results, as we never tried this.

  • you can actually include freeframe-dlls directly into vvvv. just drop the dll onto vvvv and you´re done. while this sounds like the way to go, this is impossible to do in a more generic way: there is no established standard of what is in a dll and how to map the various functions to pins within vvvv. While we are thinking of supporting other dll-formats also, currently the freeframe standard is the only type of dll which can be converted automatically to a vvvv node. You may be able to write a Freeframe-dll which encapsulates your driver, but note that freeframe is by no means a generic plugin format, so it may involve a series of workarounds to do anything else with it but video effects. For example the standard doesnt include outputs. Joreg is working on putting some examples online

#3

Thanks Herr Oschatz,

I though it to be difficult. Mhhhh. It’s no a freeframe-dll - i guess -, because there are output-functions. the only way to get it done is by writing my own pascal-program … i have a source in delphi. probably that will help.
The vellemann kit is from conrad electronics. simple usb-board with 2 analog inputs and 5 digital and 8 digital outputs. I’m trying to get some sensors to work, but i’m not very familiar with electronical things.

but thanks so far
wolfgang