NEW >>> K8090 8-Channel USB Relay Card

I’d like programming examples for the K8090 in

  • Microsoft Visual Basic 2008 Express Edition
  • Microsoft C# 2008 Express Edition
  • Microsoft Visual C++ 2008 Express Edition
  • Microsoft Visual Basic 6
  • Small Basic
  • Delphi
  • Dev C++
  • Borland C++ Builder
  • Other (post your own choice)

0 voters

[size=150]New: K8090 8-Channel USB Relay Card[/size]

  • USB-controlled relay card
  • Three button modes: toggle, momentary or timer operation
  • Timers up to 18 hours
  • Optional open collector connectivity (push button simulation)
  • Communication with the board via the supplied DLL from multiple programming languages
  • Support for Microsoft .NET
  • Optional VDR (type VDR300) transient suppression for use with inductive loads
  • LED indication for power and relay action
  • Event-driven with asynchronous I/O (no need for software polling)
  • Open protocol with detailed protocol description
  • Works on Windows 2000/NT/XP, Windows Vista and Windows 7 (32/64-bit)

[color=#008000]Included in the download package:[/color]

  • Getting Started Guide
  • Protocol Manual
  • K8090 Communications DLL (K8090D.DLL) with documentation
  • K8090 Component Library for .NET
  • Developer’s Guide with samples in Visual Basic .NET 2008 Express Edition
  • Standalone demo application
  • Drivers for Windows 2000/NT/XP/Vista/7 (32/64-bit)

[size=150]Interested? Find a Velleman dealer near you and order it now[/size]

Test your board with the standalone demo application:

Or write your own software! Control your K8090 from .NET with only a few lines of code. Includes step-by-step examples in Microsoft’s free Visual Basic .NET 2008 Express Edition!

Complete protocol description included in the installation!

And much much more!

These are really interesting facts :bulb: :slight_smile:

Anyone know how long until this kit is released (UK)??


Software and manuals are available from our website. The installer can be downloaded here: …

im no expert on binary but i think you have an error in your binary value (k8090_VisualBasic.pdf bottom of page 11) it says 01000100 when it should say 10000100

You are correct, thanks for noticing! Did you find it easy to understand the examples and the documentation?

I am not a programmer so the examples in the DLL guide did not make any sense, but the VB documentation and protocol manual were easy to understand. :smiley:

I have already made my control app, it is my first programming project :slight_smile:
But since the card is still not availabled to buy i am unable to test it :frowning:

Great that you found it to be easy to understand, the dll documentation was meant to be a little more technical :slight_smile: The K8090 will get more examples in other languages as time progresses. Even in Small Basic for those taking their first steps in programming and electronics.

The K8090 is now available at your local Velleman dealer !!!

[size=150]België / Belgique / Belgium[/size]
Verkooppunten in België
Distributeurs en Belgique
Distributors in Belgium

Verkooppunten in Nederland

Distributeurs en France

[size=150]United Kingdom[/size]
Distributors in the UK

Händler in Deutschland

You will need to find a shop near you and ask them for a good price, i’m sure they will be able to help you plus they will be able to tell you what the shipping will cost will be if you want it shipped. Pricing can differ per country.

Can the relays be used to switch high voltage (A/C 240v) devices? e.g. lamps, pumps etc?

My little dream is an iphone app to control my k8090 over local network , someone can do that?

I ( also plan to do that, but I don’t no if velleman supports this plan?
If yes, let me know.


I have done a little prototype, dream came true !

Available soon

The K8090 install package contains a new tool called K8090C.exe which will be installed to the C:\Program Files\Velleman\K8090\Tools folder.

This is a console tool to operate the relays on the board without the need for programming.


p - port name - COM1, COM2, .., COM20, ..
c - channel number - 1, 2, 3, 4, 5, 6, 7, 8
f - function - ON, OFF, TOGGLE


This example toggles the third relay of the board connected to port COM17.

The iPhone application is amazing zachari, very impressive! It’s an added value for the K8090

Thanks for all the work you’ve put into creating the K8090 iPhone application and the server, the whole R&D team has already been looking at the demo video on Youtube :wink:

Excuse me, the example does not serve, I retested k8090c.
other information, k8090c only recognizes these commands?


p - port name - COM1, COM2, …, COM20, …
c - channel number - 1, 2, 3, 4, 5, 6, 7, 8
f - function - ON, OFF, TOGGLE

Refer to the protocol manual for a complete list of possibilities. The k8090C.exe is a simple application that only supports ON, OFF and TOGGLE. It also doesn’t process feedback from the card. Since it is a DOS application, it returns 0 on success, and 1 on error.

Have you published you iphone k8090 app anywhere have you got anymore info on the server side of things. I would be intrested in similar app for the K8055.